Technical Support Document
for Environmental Protection Agency (EPA) Response to
 Petitions for Reconsideration and Revision of EPA's
  Sulfur Dioxide Regulations [40 CFR 52.125(d)] and
      Attainment Dates [4lPCFRJ2.131(A) to (D) ]
          Affecting Arizona Copper Smelters
 Petitioners:   ASARCO, Inc.
                Inspiration Consolidated Copper Company
                Kennecott Copper Corporation
                Magma Copper Company
                Phelps Dodge Corporation
    Filing Dates:  February, March  and April,  1978
                     Prepared  by

         U.S.  Environmental  Protection  Agency
                       Region IX
                   215  Fremont  Street
            San Francisco,  California  94105

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                    Statement of Purpose

On January 4, 1978 (43 FR 755) the U.S. Environmental
Protection Agency (EPA) promulgated sulfur dioxide control
regulations applicable to the seven copper smelters
located in Arizona [40 CFR 52.125(d)].  These regulations
are air pollution control regulations designed to
continuously limit the amount of sulfur dioxide that can
be emitted from a copper smelter located in the
Phoenix-Tucson Intrastate Air Quality Control Region
(AQCR) or the Arizona portion of the Arizona-New Mexico
Southern Border Interstate AQCR.  The EPA also promulgated
on January 4f 1978 (43 FR 755) attainment dates of
January 4, 1981 for attainment of the primary and
secondary National Ambient Air Quality Standards  (NAAQS)
for sulfur dioxide in  these  two AQCRs  [40 CFR 52.131(A) to
(D)].  These promulgations are part of the Arizona State
Implementation Plan  (SIP) to attain and maintain  the NAAQS
for sulfur dioxide.

During February,  Marc.h and April, 1978 the  five companies
which operate primary  copper smelters  in Arizona  submitted
to EPA administrative  Petitions for Reconsideration  and
Revision of  the aforementioned regulations  and/or
attainment dates  as  they  applied  to each company's copper
smelters.  The companies  and smelters  involved, and  the
dates the Petitions  were  submitted  are as  follows:

    1.   ASARCO,  Hayden,  Arizona:   February  2,  1978.

    2.   Inspiration  Consolidated Copper Company,
         Inspiration,  Arizona:  February 2,  1978.

    3.   Kennecott Copper Corporation, Hayden,  Arizona:
         April 28, 1978.

    4.   Magma Copper  Company, San  Manuel,  Arizona:
         March 8, 1978.

    5.   Phelps Dodge Corporation,  Ajo,  Douglas and
         Morenci, Arizona:   February  2,  1978 (supplemented
         on  February 2 and  22,  1978).

On February  17, 1978  EPA temporarily  deferred the
effective  date of the January 4,  1978  regulations (43  FR
6945).

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                            -2-


This report presents the results of EPA's  review  and
analysis of the issues raised by the  five  smelting
companies in their Petitions for Reconsideration  and
Revision of 40 CFR 52.125 (d) and/or 40  CFR 52.13KA)  to
(D).  For simplicity the  issues  raised  in  the  five
Petitions have been classified  into six major  categories.
The issues related to each  category from all  five
Petitions are grouped together  and discussed  together.   A
brief explanation of proportional rollback (the technique
used by EPA to determine  the smelter  emission limits)
precedes the discussion of  the  issues raised  in the
Petitions.

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                  PROPORTIONAL ROLLBACK MODEL

       An Outline of the Major Procedures and Assumptions
        Used by EPA to Determine Emission Limitations for
     Sulfur Dioxide Emissions from Arizona Copper Smelters


    The technique used to calculate the Arizona copper smelter
emission limitations is known as proportional rollback.  The
major procedures and assumptions are as follows:

1.  Obtain about one year (or more) of ambient sulfur dioxide
    data from several monitors in the vicinity of each copper
    smelter  (July 1973 to November 1974).

         Assumption No. 1;   If the data year  is not
             unusual, monitoring for about one year  (or more)
             implicitly accounts for variable  meteorology
             (dispersion).

         Assumption No. 2;   The ambient monitors  are
             located at the points of maximum  concentrations  for
             each NAAQS averaging time.  This  was  not  achieved
             as discussed below.

2.  Choose  the highest sulfur dioxide ambient reading (A)  from
    any monitor  in the vicinity of a smelter.  The  highest
    value was selected because  (1) the period of  record  was
    incomplete  (see November, 1977 TSDf page  4),  and  (2)  all
    points  of maximum concentration were  not  monitored  (based
    on dispersion modeling  results; see November,  1977 TSD,
    page 7).

         Assumption No. 3;   The highest measured  ambient
             value  is equivalent to the  second highest expected
             value  in the vicinity  of  the  smelter.

    This assumption  is conservative.   If  the  period of  record
    had been complete and  if all points of  maximum
    concentration  had been  monitored,  it  is likely that  the
    true second  high reading would have been  larger than the
    highest value  recorded  and  used by  EPA  in 1973-1974.

3.  Calculate a  rollback  ratio  equal  to B,  where
                                        A

         A  = highest measured sulfur  dioxide  ambient
             concentration
         B  = appropriate National  Ambient Air Quality
             Standard  (NAAQS)  for  sulfur  dioxide.

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                            -2-
    This ratio results from the use of the proportional
    rollback model contained in 40 CFR 51.13(e), assuming
    zero background concentration for sulfur dioxide  (see
    calculations and assumptions in step No. 5) .

4.  Determine the sulfur dioxide emissions from the
    smelter on the day of the highest measured  ambient
    concentration (i.e., current emissions).

         Assumption No. 4;  The 24-hour emission estimates
            provided to EPA by the smelters are
            representative estimates of actual  sulfur
            dioxide emissions on that day.

    Since continuous emission monitoring data was not
    provided by the smelters for the period of  EPA's
    ambient monitoring  (1973 and 1974) , EPA used the
    smelter's emission estimates.  These estimates were
    generally based on 24-hour sulfur balance data.  The
    key assumption in sulfur balance calculations is that
    sulfur entering the smelter on a particular day also
    leaves the smelter on the same day in some  form (as
  '  sulfur in the reverberatory furnace slag, as sulfuric
    acid, or as sulfur dioxide emissions to the ambient
    air) .  This assumption is not completely accurate  in
    all cases because there is some time delay  between the
    period when the sulfur enters the smelter and when it
    leaves the smelter.  However, this assumption is the
    best approximation available, since there  is presently
    no known procedure available to EPA which more
    accurately predicts the percentage of sulfur entering
    a smelter on a particular day which will leave the
    smelter on that day.  In summary, EPA used  the best
    emission data available from the smelters  to determine
    "current emissions."

5.  Calculate the allowable emissions from:
     [allowable! = [current  j|B\
     I emissions I   lemissionsjl A I
                                       'rollback ratio
    This calculation is based on the use of the
    proportional rollback model  [40 CFR 51.13(e)J,  and  it
    is equivalent to the method used by EPA in its
    January 4, 1978 promulgation  (as described on page  8
    of the November, 1977 Technical Support Document) as
    follows:

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                        -3-
The proportional rollback model  [40 CFR 51.13(e)]
states:

     percent reduction required  =  A  - B  (100)
                                    A  - C

     where A = Existing air quality at the  location
               having the highest measured  or
               estimated concentration
           B = National Standard
           C = Background concentration

     Assumption No.  5;  The background concentration
         (C) is zero, since  the copper  smelters  are
         isolated point sources of sulfur dioxide.
         This is equivalent  to assuming that all
         emissions which contributed to the  high
         ambient sulfur dioxide concentration
         originated  from the smelter  (or  two smelters
         in the case of Hayden, Arizona).   The
         assumption  of zero  background  concentration
         benefits the smelter, since  it results  in a
         larger allowable emission  limitation than
         would  result from  an  assumption  of some amount
         of background sulfur  dioxide  concentration.
         Therefore,

         percent reduction  required   =  A - B (100)
                                       A - 0

                                     =  A - B (100) ,
                                          A

         which  is equivalent to  the  formula on page 8
         of the TSD. Also  from  page  8  of the TSD:
         e|=[current ill
         si  (emissions!!
I allowable! = [current
(emissions! (emission!



           =lcurrent  I
            [emissions!

           = fcurrent  "1
             emissions!
- (percent reduction required)
             100
                       1 - 100
                       1 -
     100

  (1 - B/A)

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                            -4-


             = (current  )(E]
               lemissionsftAy

        Assumption  No.  6;   The  24-hour  emission estimates
           provided to  EPA by the smelters represent the
           emissions which actually influenced the
           highest  ambient sulfur dioxide concentrations
            (24-hour and 3-hour).

        This assumption is not  completely accurate in all
        cases  because there are variable emissions and
        variable time delays between the period when
        sulfur  dioxide  is emitted and when it influences
        an ambient  sulfur dioxide monitor reading.
        However, this assumption is the best
        approximation available,  since there is presently
        no known procedure available to EPA which more
        accurately  predicts the sulfur dioxide emissions
        which  influenced an ambient sulfur dioxide
        concentration measurement.

        Assumption  No.  7:  Under the given meteorology
            (disperson)  which existed on the day of the
            highest  ambient sulfur dioxide concentration,
            the ambient concentration is directly
            proportional to the actual smelter emissions
            on that  day (see November 7, 1977 TSD pages 4
            and 5,  for explanation of why  EPA did not use
            dispersion modeling to calculate the smelter
            emission limitations).

         Assumption No. 8:  The highest measured ambient
            sulfur  dioxide concentration  is the same
            concentration  that would occur each year with
            the same meteorology  (dispersion) and
            emissions.

6.  Perform these calculations for  the 3-hour,  24-hour and
    annual NAAQS for sulfur dioxide.  The  smallest  (most
    stringent)  emission limitation which  results  is  used
    as the SIP emission limitation  for that smelter.

         Assumption No. 9:  An hourly emission  rate
            averaged over  a moving  ("running")  6-hour
            period  will ensure that  the  3-hour  NAAQS  for
            sulfur  dioxide is attained and maintained.

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I    Adequacy of Public Notice and Hearings (ICCC, KCC
     and PD):

     Inspiration and Phelps Dodge both claimed that EPA had
     not satisfied the public notice and hearing requirements
     specified by law.  Within this general criticism of EPA
     procedures, Phelps Dodge specifically claimed that:

          1.   The public hearing was not timely in that
               there was excessive time between the proposed
               rulemaking on October 22, 1975 and the final
               promulgation on January 4, 1978, and
          2.   The final promulgation is substantially
               different than the proposed rulemaking.

     In addition, Kennecott argued that it should have been
     provided an opportunity to cross examine EPA's witnesses
     regarding the technological feasibility of achieving
     compliance with  the EPA limits.

     EPA does not believe that it has violated any of the
     public  notice and hearing requirements of either the
     Clean Air Act, 40 CFR 51.4 or the Administrative Pro-
     cedures Act.

     On October 22, 1975 EPA proposed the new smelter regula-
     tions  (40 CFR 49362).  In December, 1975 a public hearing
     was held on the  proposed regulations in Douglas, San
     Manuel, Winkelman, Miami, Morenci and Ajo, Arizona.  Each
     location of the  hearing was attended by EPA  officials,
     smelter operators, State officials, and the  public.
     Testimony was received during the hearing, and written
     comments were submitted to EPA by various individuals
     and organizations following the hearing.  All comments
     and testimony presented to EPA on the proposed rulemaking
     were considered  in the process of promulgating these
     regulations.  During the course of these proceedings
     30 days notice of the public hearing was given.  The
     EPA proposal was available to the public, a  record of
     the hearing was  made, EPA reviewed and summarized the
     comments submitted and the major comments were discussed
     in the  preamble  to the final rules  (43 FR 755) as specified
     at 40 CFR 51.4.  Therefore, EPA has followed the require-
     ments of 40 CFR  51.4 and the Administrative  Procedures
     Act in  this final rulemaking.

     On pages 24-28 of its Petition the Phelps Dodge Corpora-
     tion claims that the regulations are invalid, since the
     public  hearing was not held in a timely fashion and an
     excessive period of time elapsed between the proposed

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                            -2-


    rulemaking on October 22, 1975 and the final promulgation
    on January 4, 1978.  Neither the Clean Air Act nor the
    Administrative Procedure Act specify a maximum time for
    finalizing rules after the date of the proposal.
    Further, it is clear that a reasonable time be allowed
    for review and consideration of public comments.  Due
    to the importance and complexity of the regulations,
    this process took longer than EPA had initially estimated,
    Several factors contributed to the length of the review
    process:

         1.   The regulations are complicated and effect
              7  of the 16 copper smelters in the United
              States.
         2.   EPA's evaluation, summary, and response to
              the numerous  comments presented at the public
              hearing  required  substantial  time.
         3.   Additional air quality modeling was performed
              and evaluated for each  smelter. I-1!
         4.   Throughout 1976  a considerable amount of EPA
              staff time was devoted  to  review  and  analysis
              of Arizona's  proposed smelter regulations.
              At Arizona's  request EPA^prepared comments
              on the proposed  regulations.  Despite
               strongly negative comments from EPA,  Arizona
               subsequently  submitted  these  regulations  to
              EPA  as  SIP Revisions  on January 7,  1977.
              These regulations are discussed in greater
               detail  in Section II  of this  report.
          5.    Finally during the  last half  of  1976  and  the
               first half of 1977  EPA  knew that  amendments
               to the  Clean  Air Act  were pending in  Congress.
               It was  clear  that these new amendments  would
               contain some  provisions affecting smelters,
               but the exact nature  of these provisions  was
               not known.  After the amendments  became law
               on August 7,  1977 the smelter regulations had
               to be changed to be consistent with the new
               Act.

     Considering all of these factors, EPA believes that its
     actions were timely.
JT3These modeling~1results were not used as the basis for
     the final rule, but were used to evaluate whether or
     not the ambient air quality monitors were located at
     the points of highest expected concentrations.

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                        -3-
On pages 24-28 of its Petition the Phelps Dodge Corpora-
tion also claims that the regulations are invalid
because the final regulations are substantially different
than the proposal.  Again EPA disagrees with this
assertion.  The most obvious difference between the
proposal and the final regulations is the absence of
three of the four major paragraphs of 40 CFR 52.125 in
the final rulemaking.  The October 22, 1975 proposal
contained provisions for fugitive emission control  (d),
"ultimate" emission limitations  (e), alternative emission
limitations  (f) and excess emission reporting require-
ments  (g).  The January 4, 1978 regulations contain
only the ultimate emission limitation provisions  [now
paragraph  (d)] because it was determined by EPA that
the 1977 Amendments to the Clean Air Act made inclusion
of the other three provisions inappropriate.

As explained in the preamble to the final rulemaking,
the alternative emission limitation paragraph was removed
because of changes to the Clean Air Act, i.e. the addi-
tion of a new  section 119.  The deletion of the alterna-
tive emission  limit adversely affects the smelters.
However,  the alternative emission  limitation is now
available through section-119, which provides for
deferral  of compliance with the ultimate emission limit
up to  January  1, 1988 through issuance of one or two
nonferrous smelter orders  (NSO).   The nonferrous smelter
order  is  a new enforcement mechanism for implementation
of an  alternative emission limitation, such as was
proposed  for the Arizona smelters  on October 22, 1975.
The ultimate emission limitation contained in 40 CFR
52.125(d) must be in effect before a nonferrous smelter
order  can be issued to a smelter.  EPA rulemaking to
implement section 119 was proposed on January 31, 1979
 (44 FR 6284).

The final rules of January 4, 1978 do not contain
provisions for fugitive emission control or excess  emission
reporting requirements.  As discussed in the preamble,
EPA eliminated these requirements  from the final rule-
making because these requirements presume a knowledge
of the smelter configurations to which they apply.  How-
ever, they will be promulgated for any smelter, if
necessary, when the compliance configuration of that
smelter can be determined.  That would be expected  to
occur if  any smelter elects to comply with the SIP
emission  limitation rather than seeking an NSO, or  upon
denial, expiration or termination of an NSO.  The

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                       -4-
deletion of fugitive emission control requirements does
not adversely affect the smelters, since the deletion
imposes fewer regulatory requirements on the smelters.
The deletion of the malfunction, or excess emission
reporting requirements could adversely affect the
smelters.  However, since EPA will promulgate these
regulations, if necessary, prior to the time when a
smelter achieves compliance, the effect is only
temporary and will not adversely affect the smelters
from a practical standpoint.

As part of the rulemaking process EPA received and
evaluated numerous comments regarding the proposed rules.
The comments were summarized in the preamble to the
final rulemaking.  In addition, the preamble contains
EPA's response to the major comments received.  Where
appropriate, the regulations have been changed to reflect
the comments.  However, if the comments were not appro-
priate and did not result in any change to the regula-
tions, EPA's reasons for rejecting the comments are
discussed in the preamble.  Some of the comments related
specifically to the provisions contained in the "ultimate"
emission limitation paragraph, and some changes were
made to these provisions to reflect comments.  For
example the emission limitation for the Magma Copper
Company is less stringent than originally proposed.
Magma claimed that use of monitoring data from the Slag
Dump monitor was inappropriate since the monitor was
located in an area which was not accessible to the
general public.  EPA confirmed Magma's contention and
used data from another monitor to calculate the SIP
emission limit.  This new limit was less stringent than
the one originally proposed.

Further, Phelps Dodge asserted that the proposed require-
ment that continuous monitors be  located at least eight
stack diameters downstream  from any flow disturbance
would require the expenditure of  $550,000 for the
relocation of sampling ports.  After review of this
requirement, the regulation was changed to permit
location of sampling ports  at other points, if the new
location is approved by the Administrator.  This change
allows the Administrator a  certain amount of adminis-
trative discretion when reviewing the adequacy of the
existing sampling ports, yet it retains the Adminis-
trator's authority to require accurate and adequate
monitoring data.  EPA's response  to these and other
comments are discussed in the preamble to the final
rulemaking at 43 FR  757, January  4, 1978.

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                        -5-
It is EPA's conclusion that the regulation is not
"substantially different" from the proposal since the
changes to the regulation were deletions which do not
adversely affect the smelters.

On page 14 of its Petition, Kennecott argued that it
should have been given an opportunity to cross examine
EPA's experts on the technological feasibility of the
regulations based on Bunker Hill Co. v. EPA, 10 ERC
1401, 1415  (9th Circuit 1977).Kennecott's argument
lacks merit since that situation is clearly different
than in this case.  In Bunker Hill, the 9th Circuit
required that EPA make its technical experts available
for cross examination, since  EPA was imposing a
requirement based on technological feasibility.  The
reasonableness of that EPA requirement hinged on the
feasibility of installing a  sulfur burner at Bunker Hill.
In the Arizona case, technological feasibility is not
an issue.   EPA is establishing an emission  limit suffi-
cient to attain and maintain the national ambient air
quality standards for sulfur dioxide as required by
sections 110(a)(2)(B), 123 and 302(k).  As  discussed in
Section V., EPA is required  to do this regardless of
tHe  technological feasibility of the emission limitation.
The  issue  of technological feasibility can  be considered
in the enforcement process when a timetable for  compliance
with the emission limitation is established, or  under
the  provisions of section  119 (see  Section  III of this
report).

The  issue  of cross examination and  adjudicatory  hearings
was  also discussed in the  preamble  to  the  regulations
 (43  PR 757, last column  and  758,  first column, January  4,
1978) :

      "Legal Considerations.   The  question of whether
      EPA should have  held  an adjudicatory hearing
      during the public hearing for  proposed rulemaking
      was  raised by several commentators.   This question
      has  been litigated  and  resolved  by several  court
      cases.  Most relevant to this  rulemaking, the
      case of Anaconda v. Ruckelshaus,  482 F.2d  1301,
      1306   (10th  Cir.,  1973), held that neither  the  Clean
      Air  Act nor  the  Administrative Procedure Act
      compelled EPA to permit cross-examination  before
      promulgating an  SIP for Montana,  even though  the
      plan contained  S02  emission  standards applicable
      only to the  Anaconda smelter.   Furthermore, the
      legislative  history of the  Clean Air Act Amendments

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                       -6-
     confirms  the intention of Congress that adjudicatory
     hearings  are not required in rulemaking actions of
     this kind.   In this context, it is the Administra-
     tor's judgment that an adjudicatory hearing for
     this action is unnecessary.   [See also, Buckeye
     Power, Inc., et al. v. EPA,  481 F.2d 162,  172
     (6th Cir.,  1973); United~States v. Florida East
     Coast R.  Co., 410 U.S. 244,  240 (1973]."

It is EPA's conclusion that it is not required  to provide
for an opportunity to Kennecott to cross-examine witnesses
on the technological feasibility of the emission limita-
tions, since that is not an issue relevant to this case.

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                             -7-
II.   Approval/Disapproval of the January 7,  1977 Arizona
     SIP Revision (ASARCO, ICCC, KCC, Magma and PDJ ;

     All of the smelters in Arizona questioned whether EPA's
     promulgation of the sulfur dioxide regulations was
     proper, considering that an Arizona SIP revision dated
     January 7, 1977 was awaiting EPA action at the time of
     promulgation.[21  The petitions made three major points:

          1.   The EPA must act upon the January 7, 1977
               Arizona SIP Revision within four months of
               its submission, and in any event EPA must
               act prior to promulgating substitute regu-
               lations f
          2.   The January 7, 1977 Arizona SIP Revision
               conforms to the requirements of section 110(a)
                (2)(B) and assures compliance with the NAAQS,
               and
          3.   The EPA must  approve  the January  7, 1977
               Arizona  SIP Revision.

      EPA does  not agree  that any of  these objections  raised
      by the smelters are  reasons to  invalidate its sulfur
   «  dioxide rulemaking applicable  to the Arizona copper
      smelters.  The  four month  period for  SIP Revision  review
      was not satisfied  in this  case  because  EPA resources
      did not permit a thorough  review of the January  7,  1977
      Arizona SIP Revision within the prescribed time  limit.
      EPA believes that  congressional intent  places greater
      emphasis  on an adequate review than on this timetable,
      and that  an adequate review of SIP Revisions cannot be
      sacrificed merely  because of  the four month deadline.
      Furthermore, EPA is not aware of any  portion of  the
      Clean Air Act which says that it cannot promulgate
      final rules as long as there  is a pending SIP Revision
      in its possession, as the Petitions contend.  In the
      extreme,  Agency action could  be frustrated by such an
      interpretation, merely by State submittal of a continual
      series of SIP Revision packages to EPA.
      These SIP Revision issues were raised by ASARCO at
      pages 3-10; ICCC at pages 1-2; KCC at pages 1-4 and
      13-15; Magma at pages 4-5; and Phelps Dodge at pages 2,
      4 and 11-24 of their respective Petitions.

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                        -8-
Finally, as described in the preamble to the regulations,
EPA believes it has followed the proper sequence of
events leading to its promulgation of the final sulfur
dioxide rules on January 4, 1978 (43 FR 755).  On
July 27, 1972  (37 FR 15081) the Administrator disapproved
Regulation 7-1-4.1  (copper smelters) of the Arizona
Rules and Regulations for Air Pollution Control as it
pertained to existing copper smelters in Arizona.  The
Administrator also proposed on July 27, 1972  (37 FR
15096) regulations for the control of sulfur oxides
emitted by all existing smelters in Arizona.  These
proposed regulations were not finalized, because the
air quality data upon which they were based was later
found to be of questionable validity.  Instead EPA
established a monitoring network and collected air
quality data at 23  sites in the vicinity of the seven
Arizona copper smelters between July 1973 and November
1974.  Using these  air quality data, new sulfur dioxide
regulations for the copper smelters were proposed by
EPA on October 22,  1975  (40 FR 49362).  In December,
1975 a public hearing was held on the proposed regula-
tions at the six smelter towns in Arizona.  During 1976
and 1977 EPA evaluated the comments received  on the
proposed regulations and made appropriate changes to
the regulations that were necessitated by the August 7,
1977 Clean Air Act  Amendments.  On January 4, 1978
 (43 FR  755) the final EPA  sulfur dioxide regulations
for Arizona copper  smelters were published in the
Federal Register.

It was not until December  1975  (late in this  6 year
process) that  the State  indicated that it was working
on regulations to control  sulfur dioxide emissions from
copper  smelters.  During 1976 Arizona solicited comments
on tentative State  Implementation Plan  (SIP)  revisions
for sulfur dioxide  control at existing smelters.  EPA
responded to the State by  letters dated March 26, 1976,
June 25, 1976, and  August  31, 1976 indicating that the
tentative SIP  revisions contained several major defi-
ciencies and that EPA would disapprove the revisions
unless the deficiencies were corrected.  On January 7,
1977 almost 15 months after EPA's proposal of sulfur
dioxide regulations, Arizona officially submitted its
proposed SIP revision to EPA for approval.

During 1977 the EPA final rules for copper smelters
were undergoing internal review and refinement, and
during the last five months of the year they were

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    changed to be consistent with the Clean Air Act Amend-
    ments of August 7,  1977.  In 1977 EPA determined that
    it would be necessary to promulgate its own smelter
    regulations since the initial review of the Arizona
    submittal indicated that it contained several serious
    deficiences.

    Despite the Petitioners claims to the contrary, the
    January 7, 1977 State submittal does not meet the
    requirements of section 110(a)(2)(B) for at least the
    following reasons:

         1.   The ultimate emission limits do not insure
              attainment and maintenance of the NAAQS for
              sulfur dioxide, since they are based on
              technology specifications rather than ambient
              air quality data,
         2.   The ultimate  emission limits do not insure
              attainment and maintenance of the short term
              NAAQS for sulfur  dioxide  (3-hour and 24-hour
              standards), since the emission limitations
              are to be achieved on a monthly average basis,
         3.   The ultimate  and  alternative emission limits
              are not  adequately enforceable because
              compliance is determined  by a monthly "sulfur
              balance" calculation rather than direct
              measurement of actual  stack emissions, and
         4.   The alternative emission  limits permit the
               smelters to use dispersion techniques  [supple-
              mentary  control systems (SCS) and tall stacks].

     In the Clean Air Act Amendments  of  August  7,  1977 Congress
     clarified its  intentions regarding  the use of dispersion
     techniques.  Congressional  treatment of dispersion
     techniques  is reflected in  sections 110, 123  and 302  of
     the amended Act.   Under section  110(a)(2)(B) ,  a State
     Implementation  Plan must include  emission  limitations
     and such other  measures as  are necessary to assure
     attainment and  maintenance  of the National Ambient  Air
     Quality Standards  (NAAQS).   Section 302(k) defines  an
     emission limitation  as  requiring continuous emission
     reduction technology.   Under section  123,  the  degree  of
     emission limitation  (constant control) required of  any
     source in a plan under  section 110  may not be  reduced
     to any extent  by  the unauthorized use  of any  "dispersion
     techniques."£3]  Taken  together,  these sections prohibit
[3]Section 123 defines dispersion technique as a stack height
     which exceeds good engineering practice or any intermittent
     or supplemental control of air pollutants varying with
     atmospheric conditions.  Regulations implementing section
     123 were proposed by EPA on January 12, 1979 (44 FR 2608).

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                           -10-
    the use of unauthorized dispersion techniques in SIPs
    to meet ambient standards.1^1   Rather they require that
    SIPs contain emission limitations adequate to attain
    and maintain NAAQS through the use of continuous emission
    reduction technology (constant controls) alone.  Conse-
    quently, such dispersion techniques cannot be included
    in a control strategy demonstration submitted as part
    of an SIP.  Because the Arizona regulations provide for
    the use of dispersion techniques in lieu of the required
    degree of emission limitation, they cannot be approved
    under section 110 of the Act.

    Action on the approval/disapproval of the January 7,
    1977 SIP revision submittal is deferred at this time,
    since the regulations were formally withdrawn from
    consideration by Arizona on May 30, 1978.  In a letter
    to EPA, Arizona indicated that EPA action on the SIP
    revision submittal should be delayed until Arizona
    reanalyzed its regulations.  By letter dated June 12,
    1978 the Administrator informed the Governor that EPA
    would take no further action on the SIP Revision
    submittal until the package was reactivated or modified.
    To date the package has not been reactivated or modified
    by Arizona as an SIP Revision submittal.  Under these
    circumstances EPA will not take any action on the State
    submittal.

    Finally, EPA disagrees with the Petitioner's contention
    that EPA  is required to approve the January 7, 1977
    Arizona SIP Revision submittal.  Approval of State  SIP
    Revisions is a discretionary act by the Administrator.
    As discussed in the opinion of the U.S. Court of Appeals
    for the Ninth Circuit in  Kennecott Copper Corp. v.  EPA
     (Kennecott II), 572 F.2d  1349, 1354:
[4]   Section 123  does  authorize  sources  currently  using
     dispersion techniques  to receive  full  credit  for  their
     dispersive effects  in  determining the  required  degree
     of  SIP emission limitation,  if  the  stack  height was  in
     existence or the  dispersion technique  implemented prior
     to  the passage  of the  Clean Air Act of 1970.  With one
     minor  exception (which applies  to certain coal  fired
     power  plants),  only sources which qualify for this
     credit or whose stacks do not exceed good engineering
     practice stack  height  may have  the  effect of  the  dis-
     persion techniques  considered in  establishing the degree
     of  emission  limitations required  in the applicable SIP.

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                       -11-
     11 It  is  clear  that  the Administrator  has  a  non-
     discretionary duty to make  a  decision  regarding
     the  State  revision.  The Administrator,  however,
     retains a  good  deal of  discretion as to  the
     content of that decision.   The  Supreme Court's
     observation set out above makes plain  that the
     Administrator's duty to approve a revision depends,
     not  only on whether there will  be a  timely attain-
     ment and maintenance of ambient air  standards, but
     also on whether it satisfies  the "other  general
     requirements" of section  110(a)(2)	  The
     Administrator must approve  a  revision  only when
     the  SIP, as revised, meets  all  the requirements  of
     section 110(a)(2).  Determining whether  such is
     the  case requires the  fusion  of technical  know-
     ledge and skills with  judgment  which is  the
     hallmark of duties which  are  discretionary.   To
     classify them as "not  discretionary" to  make
     available section 304(a)(2) jurisdiction is  to
     stand words on their head in  an effort to  provide
     jurisdiction when Congress  intended  that none
     exist."

The Administrator is required  to approve  an SIP revision
only if it meets all of the requirements  of section
110(a)(2) of the Clean Air Act.   The decision as  to
whether this is the case involves the exercise of
discretion by EPA.  Since the  Arizona SIP revision
submittal does not meet all of the requirements of
section 110(a)(2), EPA is not required to approve it.
In fact it is required to disapprove the submittal,
since it does not satisfy all of the requirements of
section 110(a)(2).

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                            -12-


III.  Section 119 and Nonferrous Smelter Orders (NSOs)
     (ASARCO, ICCCf Magma and PD);

     All of the smelters in Arizona except Kennecott raised
     the issue of section 119 of the Clean Air Act and Non-
     ferrous Smelter Orders  (NSOs)  in their Petitions.I3*
     There were three major points made by the smelting
     companies:

          1.   The requirement to submit a compliance
               schedule by March 5, 1978 is unreasonable,
               in part because there are no regulations for
               implementation of the NSO program,
          2.   The EPA sulfur dioxide regulations applicable
               to the Arizona smelters are incomplete and
               invalid because they do not contain provisions
               for issuance  of NSOs, and
          3.   The EPA must  follow rulemaking procedures for
               the NSO program rather than rely  on a  "Guidance
               Document."

     EPA believes  that all.of  the objections raised by  the
     smelters  regarding  the  NSO program have been resolved
     and that  these  issues are now moot.  While  the 1977
     Amendments  sharply  restrict the permissible uses of
     dispersion  in SIPs,  they  also grant  special relief to
     the nonferrous  metals industry.   Section  119 of  the Act
     establishes a new enforcement mechanism  called a
      "primary  nonferrous smelter order"  (NSO), under  which  a
      smelter may temporarily defer compliance  with  its  SIP
      sulfur dioxide  emission limitation and instead meet
      ambient standards  through the use of dispersion  techni-
      ques  and  interim constant controls.   EPA began informal
      rulemaking procedures  to  implement section  119 by
      proposing regulations  on January  31, 1979 for  issuance
      of Nonferrous Smelter  Orders  (44  FR  6284).   EPA  is no
      longer relying on  a "Guidance  Document"  to  implement
     'section 119.

      The NSO program is similar to  the program for  smelters
      announced in  the Stack Height  Increase Guideline
      (February 18, 1976, at 41 FR 7450) with  certain  impor-
      tant differences.   As  was the  case under the Guideline,


      These nonferrous smelter order issues were raised by
      ASARCO at pages 10-14;  ICCC at page  2; Magma at pages
      3-4;  and Phelps Dodge at pages 3-5 and 32-36 of  their
      respective Petitions.

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                       -13-
a smelter is eligible for an NSO if it cannot afford
the control equipment (and associated process changes,
where relevant)  necessary to comply with its SIP
emission limitation.  Eligibility is to be determined
on a case-by-case basis by the Administrator.  Unlike
the Guideline, section 119 specifies a definite date by
which a smelter must comply with the SIP requirements:
January 1, 1983, unless the smelter receives a second
NSO, in which case the latest possible compliance date
is January 1, 1988.

Section 119 also requires the use of certain interim
control measures that are essentially the same as under
the Guideline.  Dispersion may be used to meet ambient
standards, together with interim constant controls to
reduce total sulfur dioxide emissions into the atmos-
phere.  With respect to interim constant controls, the
statute makes mandatory what had been EPA policy under
the Guideline:  smelters which already treat their
strong sulfur dioxide gas streams with sulfuric acid
plants (or other constant control systems), and which
use dispersion to meet ambient standards, cannot be
required to install additional constant control systems,
such as scrubbers, during the term of the first NSO
unless EPA determines that such additional constant
control systems are adequately demonstrated to be
reasonably available.  Unlike prior policy under the
Guideline, however, a smelter which has no constant
controls may receive a waiver of the interim constant
control requirement if the cost of installing such
controls would necessitate closure of the smelter.
Section 119 also retains the requirement that a smelter
conduct or participate in a research program to develop
improved means of meeting its SIP emission limitation.

The requirements for the use of supplementary controls
under section 119 are also similar to thoseyimposed
under the Guideline.  The systems must be reliable and
enforceable, and smelters will be required to assume
legal liability for violations of NAAQS for sulfur
dioxide in designated liability areas (DLAs).

Finally, NSOs under section 119 will require the control
of fugitive emissions of sulfur dioxide, where necessary,
The fugitive emission control measures that may be
required are part of the interim measures necessary to
prevent violations of the NAAQS during the term of NSOs.

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                       -14-

On January 4, 1978 EPA stated that it expected each
smelter in Arizona to apply for an NSO under section 119,
that application for an NSO could be made by the smelters
after the effective date of the sulfur dioxide regula-
tions, and that guidance concerning the application for
an NSO could be obtained from the EPA, Region IX office
(43 PR 759, first column).  On February 17, 1978 at
43 FR 6945 EPA deferred the effective date of the
sulfur dioxide regulations until such time as the
section 119 NSO regulations are established.  This
action moots the first issue by defering the March 5,
1978 date for compliance schedule submittal.

With regard to issue two  (the alleged incompleteness of
the sulfur dioxide regulations because they lack provi-
sions for issuance of NSOs), the January 31, 1979
proposal of nonferrous smelter order regulations and
their eventual promulgation will also moot this issue.
Further, the Arizona smelter regulations and the non-
ferrous smelter order regulations are two  separate
issues, even though they must be coordinated, integrated,
consistent and considered  together.  The smelter regula-
tions do not have  to contain provisions for nonferrous
smelter orders.   These provisions are to be provided
separately in  40  CFR Part  57.  Conversely  the nonferrous
smelter order  regulations  in 40  CFR Part 57 do  not need
to contain the smelter emission  limits, which appear  in
40 CFR Part  52.   However,  before a  smelter is eligible
for an NSO,  an emission  limit must  be in effect under
Part 52 provisions.

In addition  EPA will  follow rulemaking  procedures  in
the development of NSO  regulations.   In fact  this
process was  begun with  the publication  of  proposed
rulemaking for the NSO  program on January  31,  1979
 (44 FR 6284).   The proposal states  that the NSO regula-
tions would  provide for the temporary suspension  of  SIP
requirements during the  processing  of timely  NSO
applications.   The application for  an NSO  would be
initiated by a letter of intent submitted  by  the  smelter
owner to  the State or to EPA,  at the owner's  election.
 If a letter  of intent is submitted  within  two weeks
after the effective date of these regulations (or of
SIP emission limitations promulgated subsequently,  as
applicable), the  smelter would not be required  to comply
with its  SIP sulfur dioxide emission limitation during
the time  needed to formulate a complete application.
This suspension of the  emission limitation would  also
continue  for the  period necessary to complete action on
a timely  application.   EPA believes that this is  consis-
 tent with the general intent of Congress that smelters
have an opportunity to apply for NSOs as an alternative
 to compliance with their SIP emission limitations.

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                            -15-
IV.   Startup,  Shutdown and Malfunction Regulations (KCC):

     On pages 14 and 16 of its Petition Kennecott Copper
     claimed that the EPA sulfur dioxide regulations are
     invalid because they do not include provisions for
     excess emissions which are beyond the source's control.
     These "technical" violations could occur during periods
     of startup, shutdown and malfunction.  Kennecott con-
     tended that EPA was obliged to include these provisions
     because (1) the 9th Circuit Court required it at Bunker
     Hill Co. v. EPA 10 ERC 1401, 1413, n. 35 (9th Cir. 1977),
     and(2) EPA had prescribed similar provisions for new
     sources and for existing smelters without precise
     knowledge of the smelter configurations involved.  (See
     "Draft Guidance," pp. 51 et seq., and New Source Per-
     formance Standards at 40 CFR 60.165(d), explained at
     42 FR 47125, November 1, 1977.)

     EPA agrees that it must promulgate certain startup,
     shutdown and malfunction regulations in order-to be
     consistent with 9th Circuit Court decisions (Marathon
     Oil Co. v. EPA, and Bunker Hill Co. v. EPA).  However,
     as indicated in the preamble to the regulations (43  FR
     758, column 3, January 4, 1978),  EPA did"not finalize
     excess emission  (i.e. malfunction) reporting requirements
     because it did not have knowledge of the smelter config-
     uration necessary to comply with the SIP.  EPA believes
     that such knowledge is necessary prior to finalizing
     these provisions for excess emissions.  Provisions for
     excess emissions will be promulgated for any smelter,
     if necessary, when the compliance configuration of the
     smelter is known.  The two examples cited by Kennecott
     where EPA promulgated excess emission provisions without
     precise knowledge of source configuration involve
     different situations than exist in this case.  The NSPS
     and nonferrous smelter order (NSO) excess emission
     provisions involve specifications of technology which
     are not primarily designed to protect NAAQS.  The excess
     emission reporting provisions of these Arizona smelter
     regulations will, if necessary, be part of the plan to
     ensure attainment of the NAAQS.

     If Kennecott chooses to comply with the SIP limit rather
     than apply for an NSO, EPA will promulgate these provi-
     sions.  It is expected that they will be similar to the
     provisions applicable to smelters which will be issued
     NSOs (44 FR 6289, 6290 and 6298) .  The NSO excess
     emission reporting provisions are designed to encourage
     good operating and maintenance practices at smelters,
     without penalizing any smelter for excess emissions

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                       -16-


resulting solely from unavoidable equipment malfunctions,
and without undermining the enforceability of the
emission limitations.  These provisions would require
the reporting of all excess emissions, but would not
treat those which the smelter operator is able to
demonstrate resulted from genuine malfunctions and as
to which the operator took appropriate remedial action,
as violations of the emission limitations.  This
exemption is consistent with the decision of the Ninth
Circuit Court of Appeals in Marathon Oil Co. v. EPA,
564 F.2d 1253 (1977) .

Under the proposed nonferrous smelter order  (NSO) regu-
lations, any sudden  and unavoidable breakdown in process
or control equipment is considered a malfunction and
not a violation.  This definition of malfunction is
intended to account  for all genuine, unforeseeable equip-
ment problems which  result in excess emissions from the
control system.  The NSO definition of malfunction also
expressly recognizes that an unavoidable problem can
appear suddenly, but be most appropriately repaired a
number of days  later.  Control or process equipment
startups and shutdowns resulting from malfunctions are
also covered by the  exemption.  The NSO malfunction
provisions are,  however, designed to promote improved
operation and maintenance procedures by refusing to
exempt as malfunctions those breakdowns that could have
been foreseen and avoided by the use of such procedures.
The malfunction exemption does not apply where the
malfunction results  from a  serious design deficiency
which the smelter owner has failed to  correct; nor does
it apply to excess  emissions which result from scheduled
maintenance, such as catalyst screening.

These regulations would also treat as  violations any
excess emissions occurring  during bypassing  of control
equipment, unless the  bypassing  is necessitated  by  a
malfunction.  Except as discussed below,  the provisions
therefore effectively  prohibit bypassing  during  periods
when the acid plant is shut down for  scheduled mainte-
nance, and when more process off-gas  is reaching the
plant than  it is designed  to handle.

First, scheduled maintenance is  only  that maintenance
which needs to  be performed on a routine  basis,  on  a
reasonably periodic or predictable  schedule.  The best
example of  scheduled maintenance is screening of catalyst
in an acid plant converter.  Maintenance  necessitated

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                       -17-
by the detection of an actual, impending, or developing
(unforeseeable)  equipment failure will usually be
treated as malfunction-related, rather than scheduled.
The malfunction provisions thus encompass many of the
circumstances which the companies have previously
identified as shutdowns for scheduled maintenance.

Moreover, many smelters already schedule periodic
shutdowns for maintenance purposes.  The Agency believes
that careful scheduling of acid plant maintenance
cycles would allow a substantial part of that mainte-
nance to be performed during these previously scheduled
smelter shutdowns.  Furthermore, knowledge that the
smelter is scheduled to be shut down for maintenance
allows the operator to plan in advance for its projected
inventory needs during the shutdown.  This advance
planning results not in loss of production, but simply
in its rescheduling.  The Administrator also notes that
the use of SCS, which the operators seek, also entails
production rescheduling, and has apparently proved
feasible.

Second, the Administrator believes that permitting
planned operation without the use of any constant
controls during periods of scheduled maintenance  is
inconsistent with the requirements of section 110 and
the intent of Congress.  In requiring the use of
constant controls, Congress has  implicitly placed
control equipment on a par with  production equipment:
each  is integral to the operation of the facility.
Just  as a smelter cannot operate without its production
equipment, and  schedules a shutdown for  the periodic
maintenance of  that equipment, the smelter likewise
cannot operate without another integral  system,  its
continuous emission reduction equipment.  In short,  to
permit regular,  scheduled periods of uncontrolled
emissions is not consistent with the requirement  for
operation with  continuous controls.

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V.   Technological and Economic Feasibility (KCC and PD):

     Phelps Dodge (pages 28-31 of its Petition and pages
     1-3 of its Supplemental Comment) and Kennecott (pages
     2, 4-6 and 13-16 of its Petition) claimed that the
     sulfur dioxide regulations are not proper because it is
     technologically and economically infeasible for a
     smelter to comply with the regulations.  EPA cannot
     agree that technological and economic infeasibility
     make the regulations improper or invalid.  Furthermore
     it is not EPA's duty to explain in detail how each
     smelter is to achieve compliance, as contended by
     Phelps Dodge.

     Section 110(a)(2)(B) of the Clean Air Act requires that
     EPA establish emission limitations which are sufficient
     to attain and maintain the national ambient air quality
     standards (NAAQS) regardless of whether or not the
     limitations are technologically or economically feasible
      [see also Union Electric v. EPA, 427 U.S. 246 (1976)].
     The issues of technological and economic feasibility
     can be considered in the enforcement process when a
     timetable for compliance with the emission limitations
     is established.J^ftrLhe case of nonferrous smelters, a
     special smelter specific Section ,llj9 was added to the
     Clean Air Act on August 7, 1977»  m provides a specific
     mechanism through which to consider technological and
     economic feasibility prior to requiring compliance with
     the SIP emission limitations.  Section 119 provides
     that a smelter may be  issued a nonferrous smelter order
      (NSO) if additional sulfur dioxide controls are either
     technologically or economically infeasible.  The first
     such NSO may not extend beyond January 1, 1983, while
     the second, and last NSO, may not extend beyond January 1,
     1988, if it is issued.  Regulations implementing
     Section 119 of the Clean Air Act were proposed by EPA
     on January 31, 1979  (44 FR 6284).

     A.   Background Concerning Control of  Stack Emissions
          in SIPs

          To assure the attainment and maintenance of the
          NAAQS, the Clean  Air Act of 1970  directed the
          States to formulate implementation plans for the
          control of each criteria pollutant.  States were
          to develop a  combination of emission limitations
          and other measures, such that the total mix of
                               -1-

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emission limitations and other measures would
result in the attainment and maintenance of standards.
Section 110(a)(2)(B);  Train v. NRDC,  421 U.S. 60
(1975).

Section 110(a)(2)(B) of the Clean Air Act, as
amended, requires a state implementation plan to
include emission limitations and such other measures
as are necessary to insure attainment and maintenance
of national ambient air quality standards.  In
August, 1977 in Section 302(k), Congress made
clear that those emission. Imitations must be
achieved by the use offfionoTjant emission reduction
technology.  Under Section 123 (also added to the
Clean Air Act in August, 1977) the degree of
emission limitation (constant control) thus required
may not be reduced to any extent by use of any
dispersion technique, including stack heights in
excess of good engineering practice (tall stacks)
and supplementary control systems (SCS), unless
the stack height was in existence or the dispersion
technique implemented before the enactment of the
Clean Air Act of 1970 (December 31, 1970).  The
degree of emission  limitation required by Section
110(a)(2)(B) is that amount needed to insure that
national standards  are achieved.  The net effect
of these provisions is that SIPs must insure
attainment and maintenance of national standards
through the use of  constant control technology
alone.  The use of  any dispersion techniques in
SIPs to meet national standards is prohibited,
except as provided  in Section  123.  Regulations to
implement Section 123 were proposed by EPA on
January 12, 1979  (44 FR 2608).  Sections  110(a)(2)(B),
302(k)  and 123 do not contain  any provisions which
require or suggest  that EPA or a State must  consider
technological or economic feasibility when estab-
lishing SIP emission limitations.

If several sources  in an  area  contribute  to
nonattainment of standards, a State may allocate
the burdens of control  among  those sources,  as
long as the total reduction of emissions  is  sufficient
to attain and maintain  ambient standards.  As part
of the allocation decision, a State may,  if  it
chooses, consider whether it  is economically and
technologically  feasible  for  a particular source
                     -2-

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    to comply with a given control requirement, such
    as an emission limitation in the case of industrial
    stack emissions.  If a State determines that
    economic and/or technological infeasibility would
    prevent a source from complying with a proposed
    emission limitation, it may elect to impose a more
    stringent emission  limitation or other control
    measure on  another  source and relax the emission
    limitation  on the source for which compliance is
    believed infeasible.  If a single source's stack
    emissions are responsible for the entire emissions
    of a given  pollutant in an area, a State must
    establish an emission limitation for the source
    that will result in attainment and maintenance of
    standards,  regardless of the economic or technological
    feasibility of  controls for the source.   In such a
    case only that  source's emissions are available
    for  control, and there  is no possible "mix" to
    lessen the  burden  on that source.

         After  the  allocation has been made by the
         State, the economic  and  technological feasi-
         bility of  compliance by  a  source with an
         emission limitation  is no  longer relevant.
         Once  the emission limitations  and  other
         mea'sures necessary to  assure  attainment  and
         maintenance of standards are  established by
          the State,  compliance  with those  requirements
          is mandatory.   Union Electric v.  EPA, 427
         U.S.  246 (1976).

B.   Litigation Concerning the Issues of Technological
     and Economic Feasibility

     In early litigation (prior to the 1977  amendments),
     industrial sources claimed that EPA was required
     to determine if pollution control measures were
     technologically and economically feasible before
     approving or promulgating emission limitations
     which required their use.   These sources contended
     that Congress did not intend to compel or permit
     the imposition of requirements that could not be
     met because of technological or economic constraints.
     See, e.g.,  Buckeye Power,  Inc. v.  EPA,  481 F.2d
     162 (C.A.  6. 1973); Appalacian Power Co.  v.  EPA,
     477 F.2d 495 (C.A. 4,  1973);  South Terminal Corp.
     v. EPA, 504 F.2d 646 (C.A.  1, 1974); NRDC v.  EPA,
     507 F.2d 905 (C.A. 9,  1974).
                         -3-

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The Supreme Court faced the issue squarely in
Union Electric v. EPA, 427 U.S. 246 (1976).  The
Court held that in evaluating State implementation
plans (SIP) submitted to EPA pursuant to Section
110(a)(2), EPA was to determine only whether
emission limitations and other measures in the
plan would, if complied with, result in the attain-
ment and maintenance of national ambient air
quality standards.  The Court recognized that
failure to consider the technological or economic
feasibility of emission limitations and other
control measures could lead to the shutdown of
certain sources.  It concluded, however, that
Congress had intended the requirements of SIPs to
be technology-forcing, and had intended ambient
standards to be attained through scheduled compliance
with those requirements, regardless of their
feasibility at the time they were established.  As
long as the plan provided for the standards to be
achieved as expeditiously as practicable and in
accordance with the other requirements of Section
110(a)(2), the Court held that the Administrator
must approve the plan, even if a source might have
to  curtail or terminate production as a result.

The issue  of whether or not EPA must consider
economic  and technological feasibility when it
promulgates its own plan1 is unresolved by the
courts, despite Kennecott's assertions to the
contrary.  As previously discussed in Section  I
with regard to cross  examination of witness, the
finding that EPA  "cannot require a level of control
technology that  is technologically and economically
infeasible"£in Bunker Hill Co. v. EPA, 10 ERC
1401,  1404 (9th  Circuit~r9~77Tf is not  applicable  to
this case.  This  case involves the promulgation  of
emission  limits  which are designed to achieve  the
NAAQS  for sulfur dioxide, while  the Bunker Hill
case  involved the specification  of temporary
emission  limits  based on technological  feasibility.
*~ .jr*"*"! miniI j ill im inr 1 £conomic and  technological
feasibility considerations  are not appropriate for
promulgation of  Section  110(a)(2)  SIP emission
limitations which are necessary  to achieve the
NAAQS.  These factors may be  considered  in the
enforcement process,  or  under section 119  nonferrous
smelter orders.
                     -4-

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Further indications that the courts have not ruled
on the role of technological and economic feasibility
when EPA promuglates a plan is found in the opinion
of the U.S. Court of Appeals for the Sixth Circuit
in Cleveland Electric Illuminating Co. v. EPA, 11
EEC 1288, 1300 (6th Circuit 1978) concerning the
Ohio sulfur dioxide SIP:

     "Basically the choice of economic burden
     versus continued deterioration of the air we
     breathe was made by Congress.  In this litiga-
     tion no issue is raised concerning Congress1
     power to do so.

     "We have genuine doubt that this court has
     the power to review what we regard as petitioners'
     slightly disguised economic and technological
     infeastoility arguments.  See generally Union
     Electric Co. v. EPA, 427 U.S. 246, 265-66  [8
     ERC 2143]~Tl976)~TTootnote omitted).  [Since]
     This issue does not appear to be definitely
     resolved as to a United State* EPA designed
     implementation plan (such as we have here),
     see Union Electric Co. v. EPA, supra at 261
     n 7    1
                  »
Thus, A to the extent that control of emissions is
in fact necessary to attain standards, technological
and economic feasibility cannot limit the degree
of control required in the plan.

However, as discussed in Section III of this
report and earlier in this part (Section V),
Congress has provided a mechanism for consideration
of technological and economic feasibility in the
nonferrous metal smelting industry.  Section 119
of the Act allows a qualifying smelter to receive "
a nonferrous smelter order(s) through which compli-
ance with the SIP emission limit can be deferred
until as late as January 1, 1988.
                    -5-

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on
                   page.  &.                                A
   Emission Limitations (EL)

   All  of the smelters in Arizona questioned whether EPA
   had  correctly calculated the allowable  sulfur dioxide
   emission limitation for their smelter.   Several issues
   regarding EPA procedures were raised, but many of these
   issues were unique to one of the Petitions.   The general
   issues raised were:

   ^     T1 <^k >^ J^ *^A-1—
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VI .   The Reasonableness of the Attainment Date (PD):

     Phelps Dodge argued in its Petition (pages 1-3 and 7 of
     Supplemental Comment) that it was not reasonable to
     require compliance with the sulfur dioxide emission
     limits by January 4, 1981, primarily because "compliance
     is impossible!' aoeoi'eLiny  Lu Pliil^ Dudiju.^

     EPA does not believe that the attainment date is a
     relevant issue upon which to challenge the validity of
     these sulfur dioxide regulations.  Section 110 (a) (2) (A)
     of the Clean Air Act requires that attainment of
     primary NAAQS must be achieved as expeditious ly as
     practicable but not later than three years from the
     date of plan approval.  Thus the January 4, 1981
     attainment date was fixed by the requirements of the
     Clean Air Act and the date of publication of the regula-
     tions in the Federal Register.  Furthermore, EPA's
     indefinite delay of the effective date of these regula-
     tions on February 17, 1978 (43 FR 6945) means that the
     January 1, 1981 attainment date is no longer in effect.
     When EPA re-establishes the effective date of the .
     sulfur dioxide regulations, a new attainment date will
     be established.  The new  attainment date will be three
     years from the new effective date of the regulations
     (plan approval) as required by Section 110(a)-(2) (A) .

     Finally, under Section 119 of the Act compliance with
     SIP limits can be temporarily deferred until as late as
     January 1, 1988, through  issuance of nonferrous smelter
     orders (NSO).  If a smelter chooses to comply with
     these emission limitations rather than seek an NSO, it
     will have three years to  achieve compliance.  During
     this three years the source will be placed on a oo
          delayed compliance  order  (DCO)  under  section
     113 (d) which will  contain periodic increments  of progress
     leading to  final compliance within 3 years from plan
     promulgation.

          The Accuracy  and Validity of the Emission Data Used
          to Calculate  the Emission Limitations (ICCC, Magma~
          and PD ) :

          Three  of the  five smelting companies  challenged
          the validity  of  the emission data used to calculate
          the sulfur dioxide  emission limitations.  The
          accuracy of the  ambient air quality data  was not
          challenged by any smelter.
                               -6-

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         All  of  the  emission  data  used by EPA was  obtained
         from the  smelters.   The smelters generally based
         these emission estimates  on  a daily (24-hour
         average)  sulfur balance method.  While  the sulfur
         balance emission estimates have a  certain inaccuracy
         associated  with them,  they must be used in this
         case since  they were and  still are the  only
         emission  data available during the 1973-1974
         period  when EPA collected ambient  data  in the
         vicinity  of the Arizona smelters.  Continuous
         emission  monitoring  data  were not  available from
         all  smelters in 1973-1974 and in fact are still
         unavailable from all smelters.  Faced with the
         choice  of using the  sulfur balance data or no data
         at all, EPA elected  to use the sulfur balance data
         to calculate emission limitations. This  data was
         the best  available at that time.
         On pages 1-3 of its Petition Magma Copper claimed
         that the use of 24-hour emissions estimates based
         on sulfur balance was not an accurate measure of
         emissions during that 24-hour period.  They suggested
         using a longer time period,  specifically the ^5face
         average daily emissions based on the smelter/   '
         emissions for October, 1973  (see Section VjJ.1.
         for a more detailed discussion of this issue).  EPA
         has rejected Magma's requested change based on
         lack of supporting data, and on lack of representa-
         tiveness of a monthly average.T»Inspiration (pages
         2-3 of its Petition), and Phelps Dodge (page 5 of Me
         iff*Supplemental Comment to its Petition) argued
         that it was not appropriate to use 24-hour emission
         estimates to calculate an emission limitation
         based on a 3-hour ambient air quality reading.
The sulfur balance method is Jsased on the fact that over long
periods of time (such as a wefk, a month or a year) the amount
of sulfur leaving the smelter must be equal to the amount of
sulfur entering the smelter.  Emissions are calculated by
measuring the sulfur entering the smelter and subtracting the
sulfur leaving the smelter in slag, sulfuric acid, etc.  The
difference is the amount of sulfur emitted to the atmosphere.
For shorter time periods, such as 24 hours, it is possib^ that
sulfur leaving the smelter may not equal sulfur enterin£g£he
smelter.  This can result in inaccuracies in the calculated
emissions.  However, the method is a good first approximation
of smelter emissions.
                             -7-

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              Practical considerations dictated the use of these
              data in^nission limitation calculations.  Since
              continuous monitoring data was not available at
              each smelter, emission data had to be obtained
              from the smelter's sulfur balance data.  The
              shortest available averaging time for such data is
              24-hours.  Therefore, EPA used company supplied
              24-hour emission data to obtain a 3-hour emission
              rate with which to calculate an emission limitation
              based on a 3-hour ambient air quality reading.
              Compliance with this emission rate is determined
              on the basis of a 6-hour running average (see
..*-.  ff.   "*  yectionN JB^.).  If emission data were available
Y**'*          which used an averaging period of less than 24
              hoursj|SPA would have considered it£$ use in lieu
              of the 24-hour emission estimates.  However, in
              the absence of such data, EPA believes that the
              use of 24-hour data is the most accurate method
              available for calculation of an emission limitation.

              Furthermore, neither Inspiration nor Phelps Dodge
              has suggested an alternative approach to that used
              by EPA.  Therefore, while the use of shorter
              averaging periods may be appropriate where the
              data is available, the ICCC and PD Petitions are
              denied on this point, since EPA used the best
              40MMk» data available.  It should be mentioned
              that all emission limitation calculations inevitably
              contain a certain amount of uncertainty due to
              inherent inaccuracies in the emission data, the
              ambient ai5j(aara and the air quality model used to
              calculate the appropriate emission limitation.
              Therefore, the investigator must try to minimize
              the inaccuracies, as they can never ^e^oompletely
              eliminated.  EPA has used the most^air Duality
              jjS*v and emission data available  .  The proportional
              rollback model is a valid model with which to
              calculate sulfur dioxide emission limitations for
              these sources.   In short, EPA has exercised care
              in obtaining air quality and emission data, and
              has used these data to calculate the smelter
              emission limitations using a valid model  (propor-
              tional rollback) for isolated point sources  [40
              CFR 51.13(e)].
     Stack test  or  continuous  emission  monitoring data would be
     more accurate  than  the  emission estimates provided to  EPA
     by the  smelters.  However,  such data  does not exist for the
     Arizona smelters  during the EPA ambient air  monitoring pro-
     gram in 1973-1974.

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         The purpose of estimating emissions  is to estimate
         the emissions which actually caused  or contributed
         to the high ambient air  quality reading.  In the
         case  of  a  24-hour violation, the  emissions  on the
         day of the violation  are a better estimate  of the
         sulfur dioxide which  caused or contributed  to the
         violation  than are monthly average emission esti-
         mates.   Since both kinds of data are available,
         the use  of the daily  data is most appropriate.   In
         the case of a 3-hour  violation, the  use  of  emission
         data  with  an averaging period of  less than  24-
         hours may  be more appropriate than the use  of 24-
         hour  average data.  However, since the shorter
         averaging  period data do not exist,  EPA  used the
         data  with  the shortest available  averaging  period,
         i.e., 24-hours.  Under the circumstances this is
         the best available  approach, and  it  provides
         reasonable estimates  of  the emissions which caused
         or contributed to the 3-hour violations.

     B.   The Effect of Fugitive Emissions  and Background on
         Ambient Air Quality Readings Used to Calculate
         Emission Limitations  (ASARCO, KCC and PD):

         Three of the  five  smelting companies (Kennecott,
         ASARCO  and Phelps Dodge) challenged  the  validity
          of the  emission  limitations  for their smelters,
         because EPA had  failed to take  into  account the
          impact of  low level fugitive  emissions  on the
          ambient air quality readings  used to calculate
          those emission limitations.

          EPA recognizes  that low level  fugitive  emissions
          from copper smelters under certain circumstances
          can cause  or contribute to violations of the
          National Ambient Air Quality^tandards  for sulfur
          dioxide.  However,  for theai/jsmelters EPA cannot
          justify exclusion of the impact of 'thoq» emissions
 For example, it is clear in the case of Magma's violation on
 October 12, 1973 that emissions which occurred between
 October 13-31, 1973 could not possibly have contributed to
 the violation on October 12, 1973.  Yet these emissions are
 included as part of the monthly emission estimate which Magma
 has suggested that EPA use to calculate its emission limitation

4This issue was raised by ASARCO at page 16; by Kennecott at
pages 8-9 of their respective Petitions; and by Phelps Dodge
at pages 3-6 of *•• Supplemental Comment to its Petition.

                              .9-

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              from the ambient air quality readings which were
              used to calculate the ftirinnnn smelter emission
              limitations .
              As was stated in the Technical Support Document of
              November 1977 (page 3) and the Preamble (43 FR
              757, column 3) the EPA monitoring sites used to
              collect ambient data in the vicinity of each
              smelter in 1973 and 1974 were selected to measure
              the maximum impact of stack emissions from the
              smelter or to supplement existing smelter and
              State monitoring networks.  The monitoring sites
              in question ranged from 1.2 to 2.75 miles from the
              smelter stacks.  The table at the end of thijfcection
              summarizes the monitoring sites which recorded the
              highest 3-hour and 24-hour readingpMuring 1973-
              1974 and the distance of these monitors from the
              smelter stack(s).  Furthermore, the magnitude of
              stack emissions during 1973-1974 was generally at
              least 5 times  (and up to 20 times) greater than
              the magnitude of fugitive emissions.  As a consequence
  *"  '•  ".    of the siting criteria, the distance of the monitoring
   .,£c^^     sites from the smelters, and the fact that stack
r>o *;f ~        emissions are much greater than fugitive emissions,
cx.-H         EPA concludes that the impact of low level fugitive
  '            emissions on these monitoring sites was generally
              not as great as the impact from stack emissions
              during 1973-1974-
                            " There  is  at  thejpresent  time,  however, «•
              inadequate technical understanding  of  the  precise    .v
              relationship  of  such emissions  to measured readings fo
              to allow  any  meaningful quantitative evaluation of ^
              their impact.  These emissions  have variable
              emission  points, both at each smelter  and  from one
              smelter to another.  Moreover,  there is  presently
              no way to measure precisely the emissions  themselves,
              since their release  points are  not  well-defined.
              In sum, there is currently no accurate way to
              either model  or  measure the impact  of  these emissions
              on measured air  quality values;  no  method  for
              doing so  was  suggested  by  any commentator."
              (Preamble. 43 F.R. 757,  column  3)
              •z. Kermecott Coff *r- ;
              Kennecott Copper did suggest a  method  for  taking
              into account  the impact of low  level fugitive
              emissions (Testimony of K. H. Matheson,  December 11,
Y + C****       1975, Support Document,  Index 5, pages 5-18).
   '  . yv_<"*'"         their suggested  method  is  neither quantitative nor
              accurate  and  its numerous  assumptions  and  approxima-


                                   te-

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tions make its use in a rulemaking situation
inappropriate.

In Index 5 of its December 11, 1975 Technical
Support Document, Kennecott challenges the EPA
proportional model for a number of reasons, among
which is its alleged failure to "properly" account
for the impact of fugitive emissions (page 11).
Instead Kennecott argues that "a combination of
sulfur capture and supplementary control system"
should be allowed to insure attainment and mainte-
nance of the NAAQS in the vicinity of its copper
smelter (page 12).  Sections 123 and 302(k) of the
Clean Air Act clearly prohibit this strategy for
determination of SIP emission limitations under
Section 110(a)(2) of the Act  (see also discussion
under Section VII.H. of this report).  These
sections also prohibit the use of such a strategy
to achieve compliance with an SIP emission limitation.
However, due to  special circumstances in the
nonferrous metals industry, Congress has temporarily
allowed this strategy as an alternative to compliance
with the SIP emission limitation for any nonferrous
smelter which receives a nonferrous smelter order
(NSO) under Section 119 of the Act  (see Section
III).

Furthermore,  in  Index 5 Kennecott's challenge  to
the proportional model indicates that EPA's emission
limitations may  be either too stringent  (pages 3,
4 and 10) or  too lenient  (page 3, 4, 10 and 11).
Thus, Kennecott's own Technical Support Document
indicates that EPA has charted a  "middle  ground"
approach in calculation of the emission limitations
required under Section 110(a)(2) of the Act.
Sections 123  and 302(k) require that these SIP
emission limitations must be  achieved through  the
use  of  continuous emission reduction techniques.
Kennecott!s  suggestion that  "a combination of
sulfur  capture and  a supplementary control system"
be allowed  is specifically prohibited by  the Act/
since it  does not meet the requirement  for continuous
emission  reduction  technology.  Thus, in  Index 5
Kennecott has failed to  suggest an acceptable
replacement for  the proportional  model  used by
EPA, but  rather  has  suggested a technique (combina-
tion of constant controls  and SCS)  specifically
prohibited  by the Act.
                     -11-

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 .
ASARCO requested that EPA reconsider the emission
limitation for its Hayden Smelter based on the
impact of fugitive emissions on the ambient air
quality readings.  However, ASARCO offered no
suggestions as to how these impacts should be
considered.  To support its claim that low level
fugitive emissions impact ambient air quality
readings ASARCO refers to a draft document entitled
"AnalysJC*f the Impact of A Prevention of Signifi-
cant Deterioration Policy on the Copper Smelting
Industry"  (EPA, February 24, 1977).  This draft
document discusses the relative impact of fugitive
emissions  in comparison with stack emissions on
monitoring sites near new well-controlled smelters.
At a new smelter fugitive emissions could exceed
process emissions, whereas at  an existing smelter
with few controls, process emissions will be many
times greater  than fugitive emissions.  A well
controlled smelter meeting NSPS should remove more
than 90% of the  input sulfur to the smelter.   In
the case of the  existing smelters  at Hayden,
ASARCO removed only  33.7%  and  32.8% of the  input
sulfur to  the  smelter in 1973  and  1974, respectively.
Kennecott  at Hayden  removed «rtir49.9%  and  81.4%
of the input  sulfur  to  the smelter in 1973  and
1974, respectively  (from Arizona Department of
Health Services,  Bureau of Air Quality  Control
yearly average sulfur removal  summaries  for copper
smelters). The  ambient reading used  to  calculate
the  emission  limitations  for Hayden,  Arizona
 EPA is aware that low level fugitive emissions can
 cause or contribute to ambient air quality violations
 at some monitoring sites near smelters.  However,
 EPA~EeTieves that at Hayden the iffln^ct of low
 level fugitive emissions on the /frees efMontcromervj
 Ranch monitoring site in 1973 and 1974 was small
 in comparison with the impact of stack emissions.
  .
 Phelps DodgeJ asserted that fugitive emissions from
 its smelters influenced the ambient air readings
 from which the emission limitations were calculated.
 Specifically for its A jo smelter Phelps Dodge
 stated that the ambient readings at the South
 Tailings Dam monitoring site were:
                     -12-

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     "...disproportionately affected by fugitive
     emissions from the smelter which flow near
     ground level down the 'channel' to the
     monitor."

Phelps Dodge states that it has affected a "notice-
able reduction in fugitive emissions" through cap-
turing some of these emissions and exhausting them
to the stack,  and through changes in its converter
scheduling.  The company asserts that its emission
limitation should be recalculated to take these
changes into account.  There are at least three
problems with doing this:

%a. Many of the ambient monitoring stations have
     been replaced or removed and the quality of
     the data obtained since 1973-1974 is not as
     good as the quality of the data obtained in
     1973-1974,

   l». Any newly measured air quality data would
     also be subject to the same claims that it
     was impacted by fugitive emissions from the
     smelter, and

    . Newly measured air quality data are influ-
     enced by the operation of a Supplementary
     Control System  (SCS) which began operation in
     January, 1976.  This would give improper
     credit for  the use of dispersion techniques
     when calculating  the degree of emission
     reduction necessary to comply  with the NAAQS.
     Such credit is not permitted under Section
     123 of the  Clean  Air Act.	_
  .  .
 In  summary,  while EPA recognizes  that low-level
 fugitive emissions can have an impact on ambient
 air quality readings at some monitors in the
 vicinity of copper smelters, EPA  has no evidence
 that  the fugitive emissions significantly influenced
 the 1973-1974 ambient readings used to calculate
 the emission limitations for the  seven copper
 smelters located in Arizona.  Furthermore,  even  if
 low-level fugitive emissions were found to make  a
 "significant" contribution to these ambient readings
 there is presently no accurate way to model or
 measure the impact of these emissions on the
 individual readings.
                     -13-

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                           /3,
) a f/s^ of- *f

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The three smelters which raised the issue of           /
fugitive emissions all failed to suggest a quanti-
tative means of solving the alleged fugitive
emission "problem."  Furthermore none of the
smelting companies were able to show in a quantita-
tive fashion the magnitude of their fugitive
emissions or their impact on the ambient air
readings used to calculate the emission limit(s)
for their smelter(s).  If any smelter is able to
demonstrate that its fugitive emissions and their
impact on ambient air quality readings have been
significantly reduced, EPA will consider any
appropriate modifications to their stack emission
limitation.

Finally, EPA will publish fugitive emission control
requirements for each smelter, if necessary, when
the compliance configuration of that smelter can
be determined.  That would be expected to occur if
a smelter elects to comply with the SIP emission
limitation rather than seeking a nonferrous smelter
order (NSO), or upon denial, expiration or termina-
tion of a NSO.
It must be stressed at this point, that EPA approach
of assuming no impact of fugitive emissions when
calculating stack emission limits is conservative
from the smelter's viewpoint, i.e., it results in
less stringent emission limits.  If fugitive
emissions did have a significant impact on these
ambient air quality readings and the fugitive
emissions remain uncontrolled, then the stack
emission limits would have to be more stringent if
the NAAQS are to be attained.  In Qther words a
significant continuing impact of 
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          The following examples serve to illustrate the
          conservative nature of EPA's assumption of no
          fugitive emission impact.

          £4. General:

Stack       +        Fugitive    =  (B)   [Stack  + Fugitive]
Allowable            Allowable      (A)   [Actual   Actual  ]

          Since EPA considers fugitive allowable = 0 (i.e.,
          that they are not measured for compliance purposes,
          even though they still exist), this means that
          stack allowable can be larger than theoretically
          allowed.  In actual practice there will always be
          some fugitive emissions  and thus fugitive allowable
          is greater than zero.  If this fact were accounted
          for in EPA's methodology then the resulting stack
          allowable emission limits for each smelter in
          A/izona would be smaller (more stringent) than those
          actually calculated by EPA for the January 4, 1978
          promulgation.

          In the January 4, 1978 promulgation for the Arizona
          smelters ?//> ranged from  0.12 to 0.30, which means
          that smelter emissions have to be reduced 70 to 88
          percent from the levels  of 1973-1974 if the NAAQS  are
          to be attained.  Fugitive emissions are usually
          less than 20% of total emissions from-a smelter with
          few constant controls.
In the
              he  following examples we  assume t.hat:feiahest  ^\
              Quality Reading =  6500  ug/nr  . B  =  1300 = 0.20  I
              ^	• * A    T50"0	/

          «»  iflHIlP (i.e., 80% reduction required to
                          attain  NAAQS),
                Fugitives = 10% of total  emissions  in  1973-1974

                Total Emissions in 1973-1974  were 400  TPD.

                Case I.   Base Conditions  1973-1974


                                 TPD


                                  HO TPD
                            TtsM
                               -15-

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            c. Case II.   EPA Scheme (Fugitive allowable = 0^
               but fugitive emissions still occur.   They
               are not measured as part of compliance testing)
Stack
Allowable
From No. 1 above

?B|  ["Stack
     [Actual
Fugitive"!
Actual  J
                       Fugitive
                       Allowable
               (.20) (360 + 40) - 0 (from Case I)
               80 TPD
               Under the EPA scheme the calculated emission
               limit applies only to the stack emissions.
               The^fugltive smelter emissions are not measured
               and are not counted as emissions.  Under this
               scheme the following three example smelters
               would be in compliance with the emission limitation.

                    Case Ila.  Fugitive Emissions remain the
                               Same as in 1973-197*^(i.e.  40 TPD)
       [Smelter
                         Total Emissions =120 TPD
                    Case  II.b.  Fugitive Emissions reduced 50%
                                from 1973-1974 levels (i.e. 20 TPD)

                    So TPP
                         Total Emissions = 1«0 TPD
                                            o
                 t3\Case II.e.  Fugitive Emissions increased
                   s50%  from 1973-1974 (levels

                    SoTFP     i'e"  60
        [5~velt
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Stack
Allowable

Fugitive
Allowable
Stack
Allowable
               Case III.  EPA Scheme Modified to Account for
                          Fugitive Emissions Impact on
                          Ambient Air after Compliance is
                          Achieved.
               From No. 1 above
    fstack
    [Actual
Fugitive"!  if Fugitive
Actual J  0 Allowable
    In other words,  fugitive emissions occur
    and are measured as part of compliance
    testing.
(.20)(360 + 40)
  - Fugitive
   Allowable
               80 TPD
        • Fugitive
         Allowable
               Under the modified EPA scheme the calculated
               emission limit  applies to both  stack and  fugi-
               tive emissions  so that the  sum^^of stack plus
               fugitive emissions is a  conslzgaint.  The  fugi-
               tive smelter emissions are  measured or calculated^
               anAthen an  appropriate stack emission limit
               is calculated,  as in the following three
               examples.
                     Case  111. a.
                  Fugitive Emissions remain the
                  same as in 1973-1974 (i.e.,
                  40 TPD)
                     Stack Allowable  =  80  TPD  -  40  TPD
                                     =  40  TPD
                    HO TPP
                        MOTPP
               t««
                          Total  Emissions  =80  TPD
                               -17-

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            Case Ill.b.
            Stack f	
           (Allowably

            66 TPP
Fugitive Emissions Reduced
50% from 1973-1974 levels
(i.e.,  20 TPD)

  80 TPD - 20 TPD
  60 TPD
                  20 TPP
j   Smelter  (
                    rn
                 Total Emissions = 80  TPD

            Case 11 I.e.  Fugitive Emissions increased
                         50% from 1973-1974 levels
                         (i.e.,  60 TPD)
                            80 TPD - 60 TPD
                            20 TPD
r

\ Sme
--* Zo TPP
/-* 60 TPP
Iter |


I ^ 1
                 Total Emissions = 80 TPD
                           Ic
       Comparison of the cXj^t Illexamples with the
       corresponding Case li examples reveals that
       in each case the EPA scheme results in a less
       stringent stack emission limit than the modi-
       fied EPA scheme which attempts to account for
       fugitive smelter emissions.

       The foregoing examples all assume that equal
       amounts of fugitive and stack emissions will
       have equal impacts on air quality readings.
       This is an idealized assumption and will not
       always be true in practice.  Since we do not
       know the magnitude of smelter fugitive emission
       in 1973-1974 or their magnitude today, and
       the air quality impacts in 1973-1974 or today,
       precise statements about the how to account for
                      -18-

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        fugitive emissions cannot presently be made.
        EPA believes it has chosen a reasonable course
        with regard to fugitive emissions and emission
        limitation calculations given the lack of
        information about fugitive emissions and the
        lack of valid methods to account for the impact
        of fugitive emissions.
H
                        -19-

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                             Arizona smelter Monitoring  t>
                              for Sulfur Dioxide:   1973-1974
Smelter
ASARCO/Kennecott
Hayden, AZ
Inspiration
Miami, AZ
Magma
San Manual, AZ
Phelps Dodge
A j o , AZ
Phelps Dodge
Douglas, AZ
Phelps Dodge
Morenci , AZ
NAAQS
Exceeded
3 hour
24 hour
3 hour
24 hour
3 hour
24 hour
3 hour
24 hour
3 hour
24 hour
3 hour
24 hour
Monitoring Site
Montgomery-Reese Ranch
Montgomery-Reese Ranch
Jones Ranch
Jones Ranch
Towns ite
Golf Course
South Tailings Dam
Oxidation Pond
Pirtleville
Pritleville
Cadillac Point
Cadillac Point
Operator
EPA
EPA
EPA
EPA
Magma
Magma
Phelps Dodge
EPA
Phelps Dodge
Phelps Dodge
Phelps Dodge
Phelps Dodge
Distance From
Smelter Stack
2.2 miles!!]
2.2 miles lij
2.0 miles!;-]
2.0 mileslJ-J
1.2 miles!?]
1.9 milesL/:j
1.3 miles!?]
1.5 miles1^
1.5 milesL]
1.5 mileslJJ
2.75 miles [4]
2.75 milesm
^  -"Environmental Protection Agency,  Region IX,  "Technical  Support Document:   Final
   Regulations for Control of Sulfur Dioxide Emissions  from Arizona Copper Smelters,
   November,  1977,  Figures H,  3  and  4 and Pages 8-16.

L  ^Letter from Magma (Ridinger)  to EPA,  Region IX (O'Connell)  dated August 8,  1977.
   Arizona Department of Health Services,  "1977  Air Quality Data for Arizona,"
   July 1978,  pages 25 and 27.

"•  -"Arizona Department of Health Services,  "1975  Air Quality Data for Arizona,"
   July 1976,  page 23.

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C.   Present Smelter Configuration Versus 1973-1974
     Smelter Configuration (PD):

     On pages 3-6 of the Supplemental Comment to its
     Petition the Phelps Dodge Corporation challenged
     the validity of the EPA regulations because they
     were calculated using ambient air quality and
     emission data from 1973-74 when the smelter config-
     uration was different than the present configuration
     of the smelter.  For the Ajo smelter the Company
     claims that fugitive emissions have been reduced
     through capture of some of these emissions and
     venting them through the main smelter stack, thus
     increasing stack emissions.  The Company also
     claims that stack emissions and low level fugitive
     emissions were reduced by changes in the converter
     scheduling and operating procedures.  These changes
     resulted in fewer instances of converter gas 4*
     bypassing the sulfuric acid plant and being emitted
     from the main stack,and resulted in reduced low
     level fugitive emissions from the converters.
     Phelps Dodge claims that these changes should be
     accounted for in the determination of the emission
     limitations for the Ajo smelter.  The Company also
     states that similar considerations at the Douglas
     and Morenci smelters invalidate the emission
     limitations for these smelters.  No modeling
     results or other quantitative information was
     submitted by Phelps Dodge in support of its conten-
     tions .

     EPA has concluded that the use of monitoring data
     obtained after 1973-74 to calculate emission limi-
     tations at these three smelters is less reliable
     than the present use of the 1973-74 data as the
     basis for the EPA regulations.  The following
     discussion is offered in support of this conclusion.

     First, any new monitoring data used as the basis
     for regulation development would be subject to
     similar challenges that it is not representative
     of the present smelter configuration.  Smelter
     configurations and operations are not static, and
     they can always be said to change to some extent
     as time passes.  Further, there will always be
     some time delay between collection of the ambient
                          -20-

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data and final promulgation of a regulation based
on that data.  These time delays may range from
several months to several years and they result
from data analysis, regulation proposal, analysis
of comments on the proposed regulations, and final
promulgation of the regulation.  Thus, Phelps
Dodge could always argue that the calculated
emission limits do not represent the present
smelter configuration.

Second, any new monitoring data obtained after
1974 used as the basis for regulation development
is less reliable than the 1973-74 data because of
the many changes being made by the smelters during
the later periods.  As stated in the Federal
Register at 43 FR  757, column 3, January 4, 1978:

     "Ambient data collected during the construction
     and testing phases  of smelter modifications
     occurring during the later periods were
     unsuitable due to the lack of concurrent
     continuous emission data  and the possibility
     that  abnormal operating conditions existed  at
     some  of the smelters during this time.  In
     addition, since  1974 many of the ambient
  •  . monitoring stations have  been repaired,
     replaced, or  removed; the quality  of  the
     source-- receptor relationships  was therefore
     considered less  adequate  than during  the
     1973-74 period."

The use of 1975  air  quality  data^t generally not as
desirffable as the  use of 1973-1974 data because  of
the questionable validity of the air  quality data.
-afcfiUthe possibility of  abnormal  operating  conditions
during the, startup of sulfuric acid plantsat
                   ' «>«V/ d«tf»
 Furthermore,  the use of ambient data obtained
 during operation of a Supplementary Control System
 (SCS) at a smelter is not permitted in SIP emission
 limitation calculations, since Section 123 requires
 that the degree of emission reduction necessary to
 attain and maintain the NAAQS may not be reduced
 by dispersion techniques such as SCS and tall
 stacks.  The Arizona smelters began operation of
 SCS on the following dates:
                     -21-

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     Phelps  Dodge,  Ajo,  AZ:   January  1976  (no
       curtailments until 1977)
     Phelps  Dodge,  Douglas,  AZ:  August 31,  1975
     Phelps  Dodge,  Morenci,  AZ:  January 6,  1976
     Magma Copper,  San Manuel,  AZ:  January,  1976
     ASARCO and Kennecott Copper,  Hayden,  AZ:
       October, 1975             .
     Inspiration Copper, Inspiration, AZ:  (no  SCS)

If ambient data obtained after the SCS began
operation are used to calculate emission limitations,
the^improper credit for dispersion techniques
(SCS, in this case) would result.   Thus, the
calculated emission limits would not be sufficiently
stringent to protect NAAQS under expected worst
case dispersion conditions.  These results are due
to the fact that the magnitude of the highest
ambient air quality readings have been reduced by
the SCS initiated  emission reductions.  The use of
these data that have been influenced by SCS operation
violates one of the major assumptions of an air
quality model.  Most models  assume that the emission
rate from a source is  independent of  dispersion
conditions  and ambient air quality readings.  An
SCS varies  the emission rate of a source based  on
dispersion  conditions  and/or ambient air quality  .
readings.   Thus, the  use of  SCS influenced  data
invalidates the use of the  air  quality  model used
to calculate the degree of  emission  reduction
necessary to attain NAAQS.   Any emission  limitations
calculated  from these data  may not be sufficiently
stringent to protect  NAAQS.

Finally,  the changes  in the emissions at  the
Phelps Dodge smelters are not expected to have  a
significant impact on the SIP emission limit
necessary to  attain and maintain  the NAAQS for
sulfur dioxide.   The  use of stack emissions data
obtained since 1974 which have been reduced by
 installation of sulfur dioxide control equipment
 is not likely to produce significantly different
 limitations than would earlier data.  The explanation
 for this conclusion is that lower emissions would
 result in correspondingly smaller ambient air
 ouality readings  and smaller percentage reductions
 needed to attain  the NAAQS.  Thus,  even though air
 quality readings  may be lower, the stack emissions
                     -22-

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        which caused the air quality readings are also
        lower.   Since the smaller percentage rollback
        needed to  achieve NAAQS would be applied to smaller
        actual emissions, the net effect would be an SIP
        emission limit  similar to the SIP emission limit
        calculated by EPA from larger air quality readings
        caused by  larger stack emissions in 1973-74.
        Since Phelps Dodge  has failed to submit data which
        substantiate its claims, EPA cannot revise its
        emission limitations based  upon claims that stack
        emissions  have  been reduced.

        With regard to  fugitive  emissions, any reductions
        in low  level  fugitive emissions have not been
        measured,  nor has  the actual  amount of the past or
        present low level  fugitive  emissions been measured.
         In addition,the precise  effect  on  ambient air
        quality readings of collection  of  some  fugitive
        emissions  and discharge  of  these collected  emissions
         from a  stack  or of reduction of low  level  fugitive
         emissions  cannot be predicted for  these  smelters
         at present.   EPA has  concluded that these  changes
        will not significantly  affect the  ultimate  emission
         limit (SIP) calculations because the monitoring
         site locations  were not expected to  be significantly
         influenced by fugitive  emissions in 1«973-1974 (as
         discussed above in SectiorrW).   Phelps Dodge has
         failed to show that fugitive emissions influenced
         the monitoring data used by EPA to calculate the
         SIP emission limits.   Furthermore,  Phelps Dodge
         has failed to quantify the alleged impact of low
         level fugitive emissions on this monitoring data.
         Therefore, EPA cannot consider revision of its
         emission limitations based on the impact of fugitive
         emissions at the three Phelps Dodge smelters.
Nor has Phelps Dodge suggested how to do this, other than
the use of more recent data.  As discussed earlier in this
section the use of more recent data may not be as realiable
(due to SCS, quality assurance problems, abnormal operating
conditions, and/or lack of concurrent continuous emission
data, etc.) as the 1973-1974 data.  These problems would
make the emission limitations calculated from such data
unreliable as well.
                              -23-

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D.   The Allocation of the I&aden, Arizona Airshed
     Between ASARCO and Kennecott (ASARCO and KCC):
     >. Itee of Ct>*sist€«1- UnlisCAstiActb:
     On pages 14-15 of its Petition ASARCO claims that
     EPA erred in its division of the Hayden, Arizona
     airshed between ASARCO and Kennecott in that EPA:

   d fc.   Used a production figure for ASARCO based on
          a concentrate feed rate of 2000 tons per day,
          while it used a production figure for Kennecott
          based on a "reactor feed" rate of 1600 tons
          per day.  The term "reactor feed" may include
          flux and precipitates as well as concentrates.
          Used a sulfur content figure^based on concen-
          trate sulfur content, while it may have used
          a sulfur content  figureyjbased on  "reactor
          feed" sulfur content.
     ASARCO argues that the use of inconsistent produc-
     tion and sulfur content  figures may result in an
     inequitable division of  the  airshed.

     Review of  the EPA calculations and the  data submitted
     by both smelters  (relied upon by EPA  in its calcula-
     tions) reveals the following:

     "9.   The production capacity of the ASARCO smelter
          is 2000 tons per day of concentrates  (from
          page  1 of the letter from M. J.  Winkel of
          ASARCO to Frank M.  Covington of  EPA dated
          August 30, 1974).   This figure was used by
          EPA in its calculations.

     *.   The sulfur content  of the ASARCO concentrates
          used  by EPA was 29.4 percent.  This figure
          was obtained from the August 30, 1974 letter
          from  ASARCO  to EPA, and it represents a
          rounded figure for  the  1973 yearly average
          sulfur content of ASARCO 's concentrates.  The
          actual figure was 29.35 percent.

          The 1600 tons per day production capacity of
          the Kennecott smelter used by EPA  in  its
          January 4, 1978 promulgation came  from Exhibit D
          of the December 11, 1975 Technical Support
                          -24-

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      Document  submitted  to  EPA by  Kennecott  Copper
      Corporation,  Ray Mines Division.  Exhibit D
      is  entitled "Daily  Reactor  Feed RMD  Smelter,
      1974."  Reactor  feed does in  fact include
      concentrate,  precipitates and flux.  Thus the
      correct production  figure for Kennecott
      should  be 1500 tons per day of concentrate
      from page 1 of the  August 29,  1974 letter
      from I. G.  Pickering of Kennecott to Frank M.
      Covington of EPA.

,^.    The sulfur content  of  the Kennecott  reactor
      feed used by EPA was 30.0 percent.   This
      figure  was obtained from Exhibit C,  "1974
      Daily % Sulfur in RMD  Mill  Concentrate" of
      the December 11,  1975  Technical Support
      Document.  While this  graph represents  the
      sulfur  content of the  concentrate, it is 1974
      data.   In order  to  be  consistent with the
      ASARCO  calculations, EPA should have used a
      sulfur  content of 30.49 percent, which  is the
      1973 yearly average sulfur  content of Kennecott's
      concentrates (from  "Kennecott Copper Corporation,
      Ray Mines Division, Hayden, Arizona, Smelter
      Sulfur  Balance - 1973").

 A revised emission limit calculation sheet for the
 Hayden area  is attached. The use  of the  new
 production capacity and  concentrate sulfur content
 figures  for  the Kennecott smelter  results in a
 slightly different allocation of the available
 airshed  between Kennecott and ASARCO.  The revised
 calculations allocate 43.8  percent of the available
 airshed  to Kennecott  whereas the original calcula-
 tion allocated 44.9 percent to Kennecott.  ASARCO
 is  now allocated 56.2 percent, whereas it had
 previously been allocated 55.1 percent.

 The sulfur dioxide emission limitation for Kennecott
 has decreased  from 1750  kg/hr (3850 Ibs/hr)  to
 1700 kg/hr (3750 Ibs/hr), a decrease of 2.9  percent.
 The sulfur dioxide emission limitation for ASARCO
 has increased  from 2140  kg/hr (4710 Ibs/hr)  to
 2190 kg/hr (4810 Ibs/hr), an increase of  2.3
 percent.

 EPA will modify the existing regulation to make
 these changes  to the  emission limitations for
 ASARCO and Kennecott.
                     -25-

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          of ft
 On pages  11-13  of its Petition,  Kennecott  argued
 that EPA  did not properly divide the  Hayden  airshed
 between Kennecott and ASARCO because:

.$*    EPA  unfairly and arbitrarily allocated  55% of
      the  airshed to ASARCO and only 45% to Kennecott,
      and

      EPA  chose  to regulate emissions  from  Kennecott
      and  ASARCO to specific levels, rather than
      regulating the total of ASARCO plus Kennecott
      emissions  to a specific level.

 Regarding the first issue Kennecott stated that
 the airshed should be divided equally among  Kennecott
 and ASARCO rather than allocated on the basis of
 current plant capacity.  EPA cannot agree  with
 this contention.  EPA believes that it is  more
 equitable to allocate the allowable emissions from
 these two smelters in Hayden on the basis  of their
 actual production capacities on a baseline date.
 The equal airshed division scheme proposed by
 Kennecott is less desir^able because  it ignores
 the real  difference^^-n production capabilities  at
 these two smelters.

 As explained in detail above, EPA has allocated
 the available airshed between ASARCO  and Kennecott
 in direct proportion to their plant capacity in
 1973.  For purposes of this allocation "plant
 capacity" is defined as the maximum concentrate
 feed rate to the smelter times the 1973 yearly
 average sulfur content of the concentrate.  This
 procedure results in the allocation of 43.8
 percent of the available airshed to Kennecott and
 56.2 percent to ASARCO.  The general  procedure and
 rationale are discussed on pages 9 and 10 of the
 November, 1977 "Technical Support Document:   Final
 Regulations for Control of Sulfur Dioxide Emissions
 from Arizona Copper Smelters."  The general  discus-
 sion is still applicable, but the numbers in
 paragraphs 1 and 2 of page 10 must be changed to
 reflect the modifications discussed earlier in
 this section.

 In summary Kennecott argues that EPA should divide
 the available airshed in Hayden equally among the
                     -26-

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two smelters.  Kennecott also claims that its
arguments are supported "with historic fact and
analysis."  In fact, Kennecott's "historic fact
and analysis" does not support an equal division.
Kennecott has used general arguments to support
its request for equal division of the airshed.
EPA has considered these arguments and elected to
retain the allocation of the airshed based on 1973
smelter production capacity.

Kennecott also argued the related issue of whether
there should be two  separate emission limits in
Hayden (1 each for Kennecott and ASARCO) or whether
there should be only one emission limit.  Kennecott
argues that since total emissions of 3880 kg/hr
will assure attainment and maintenance of the
NAAQS for sulfur dioxide, then each smelter should
be entitled to any unusued portion of the total
emission limit not used by the other smelter.
However, such an arrangement would be impossible
to enforce.   If the  single emission limit were
violated, the responsibility for the violation
would be impossible  to determine.  Each  smelter
would argue that the other party was emitting more
than its fair share  of sulfur dioxide into the
air.  Therefore, EPA has determined that reliable
and enforceable regulations must include a separate
emission limit  for  each plant.  Both smelters must
comply with  their  individual emission limitations
at all times, regardless  of what is occurring at
the other  smelter.   Without two such emission
limitations  (one  for each  smelter), the  regulations
would be unreliable and  unenforceable.

Since Kennecott's  arguments  are not persuasive,
EPA will  retain its basic  scheme  for  allocation  of
the airshed  in  Hayden.   However, the  actual  allocation
has changed  slightly based on  a  reanalysis of the
data  as  requested by ASARCO and  discussed  in
greater  detail  above.   If both Kennecott and
ASARCO can agree  on a different  allocation scheme,
EPA will  consider changing the applicable  emission
limits  for the  two smelters.   Similarly, if  either
Kennecott or ASARCO submits new information  which
adequately justifies a different allocation  scheme,
EPA will  consider changing the applicable  emission
limits.   The total allowable emission^for  Hayden
will  remain the same,  however.       limit
                     -27-

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Hayden (3 Hour)

Date:  20 October 1973
Monitoring Site:  Montgomery-Reese Ranch
Site Operator:  EPA
Hourly Concentrations: 4.30, 3.10, 2.10 ppm        3
Average Concentration: 3.167 ppm x 2620 = 8298 ug/m

Percent reduction required: (100)(8298-1300) = 84.33% or 84%
                                 8298

Emissions:

     ASARCO:  56 + 83 + 84 = 223 tons sulfur
     KCC    :  2047.6  (371) =97.5 tons sulfur
               7788

Emission Limit Calculation:

     (64X97.5 -I" 223)(l-.84) = 102.6 ton/day SO,  (total)
     112)

     ASARCO:   (2000 )(.2935) = 587
     KCC    :   (1500)(.3049) = 457
                             1044 tons sulfur  (max. input)

     ASARCO:  587  =  .562    (.562)(102.6) =  57.7 tons/day S02
            1044           .             =  4810 Ibs/hr S07
                                         =  2190 kg/hr SO^

     KCC:     457  =  .438    (.438)(102.6) =44.9 tons/day SO,
            1044                         =  3750 Ibs/hr S0? ^
                                         =  1700 kg/hr S02
                               -28-

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E.   Changing Plant Configurations for Kennecott and
     ASARCO During 1973 and 1974 (KCC):

     On pages 6-8 of its Petition the Kennecott Copper
     Corporation challenged the validity of the EPA
     regulations because the Hayden emission limitations
     (for Kennecott and ASARCO) were calculated using
     data obtained during 1973 and 1974 when the configura-
     tions of both the Kennecott and ASARCO smelters
     were changing.  Kennecott argues that since EPA
     used the issue of changing plant configurations to
     preclude use of data obtained subsequent  to 1974,
     EPA should not use 1973-1974 data for calculation
     of emission limitations  in Hayden.  Kennecott  also
     references their written testimony of December 11,
     1975 regarding smelter configurations and operation.
     Specifically, Kennecott  states that the 1973
     configurations of the ASARCO and Kennecott  smelters
     are not representative of current conditions.
     Kennecott apparently  feels  that whenever  a  change
     occurs  in a smelter's configuration,  a revised    ,
     emission limit.should be developed. Kf*yf»tt did rxor
     5«UmH aA/moA«li*« A«T* tO S«brr»nf»«t» it* Cla»«v*.
     EPA does not  agree with  Kennecott's  contentions
     because:
                                                  •
     1.   Ambient  and emission  data  obtained  before or
          after  1973-1974  are less  reliable  than that
          obtained during  the EPA monitoring  program in
          1973-1974,  and

     2.   The  configuration changes  which Kennecott
          claims should invalidate  the use of 1973-1974
           data are not expected to  have a significant
           impact on the emission limitation calculations
          made by EPA.
      Data obtained prior to establishment of the EPA
      smelter monitoring network for sulfur dioxide in
      July 1973, was found by EPA to be unreliable
      (questionable).  This conclusion was based on
      public comment and analysis concerning the validity
      of data used in development of EPA's July 27, 1972
      proposed regulations for the control of sulfur
      dioxide emitted by existing copper smelters in
      Arizona (37 FR 15096).  Subsequently EPA decided
      not to finalize the July 27, 1972 proposed regula-
                           -29-

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tions.  Instead, EPA established a monitoring
network and collected air quality data at 23 sites
in the vicinity of the seven Arizona copper smelters.
Data were collected from these sites during the
period between July 1973 and November 1974.

Section 123 of the Clean Air Act does not permit a
source to obtain "credit" for dispersion techniques
implemented after December 31, 1970 in the deter-
mination of its emission limitation under Section
110(a) (2 ).$*•» Section 123 precludes the use of
data  which was  influenced by SCS and tall stacks
which began operation after December 31, 1970,
except as noted below.

Data  obtained  after July 1, 1974 cannot be used to
calculate emission limitations  for  these two
copper smelters because the operation of ASARCO's
1000  foot stack may result in an improper  reduction
in the degree  of  emission limitation required to
attain the NAAQS.   Such a reduction is not permitted
under Section  123 of  the Clean  Air  Act. .The  use
of data  obtained  after  July 1,  1974 cannot be
permitted unless  and  until ASARCO  demonstrates
that its new 1000 foot  stack  represents  good
engineering  practice  stack height ae  the  term is
used in  Section 123.   If ASARCO makes  such a
demonstration, some data  obtained after July 1,
 1974 could be used to calculate an emission limita-
 tion for the Hayden smelters.

However, any data obtained after October 1975 may
 not be used because Kennecott and ASARCO began use
 of supplementary control system (SCS)  on that
 date.  As is the case concerning tall stacks,
 Section 123  does not allow the degree of emission
 limitation required to attain the NAAQS to be
 reduced by any dispersion technique,  such as a
 tall  stack or  an SCS.  Since the SCS began operation
 in October 1975, any data obtained after that date
 may  have been  influenced by the SCS.  Therefore,   _
 it cannot be used to calculate an emission limitation
 unless it can  be shown that the operation of the
 SCS  did not influence the data.

 lpf5S&;£Efek&W tte  configuration  changes
 enumerated by Kennecott on page 6-8 of their
                      -30-

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Petition and Page 1-2 of Index 5 of the December 11,
1975 Technical Support Document will have a signifi-
cant effect on the calculation of the ultimate
emission limitations for Kennecott and ASARCO.
Further, Kennecott has failed to submit modeling
data or other quantitative information to support
its contentions.  The smelting processes at both
smelters remained essentially the same during
1973-1974 and remain so even today.  The changes
which Kennecott claims invalidate the air quality
data involved the control equipment (sulfuric acid
plants), the fugitive emissions at the smelters,
or the operation of ASARCO's 1000 foot stack.

The EPA quotation cited by Kennecott (page 7)
refers to the question of replicable operating
conditions.  The construction and testing phases
of smelter modifications which  occurred  after the
EPA data collection period are  by definition
transitory in nature.  These short-lived periods
resulted in non-replicable operating conditions
such as acid plant startup and  "break-in" periods,
discharge from  different stacks, production and
emission adjustments  due to construction, etc.
Since these "unusual  circumstances" reduce the
representativeness of the data  collected during
these periods,  use of these later  data would  not
be  appropriate.

The  "changes" to  the  smelter  configuration referenced
by  Kennecott's  Petition  (page  7)  in their written
comments of December  11, 1975  (Index 5)  do not
rubier  the  1973-1974  air quality  data  non-representa-
tiveT   During this period, Kennecott claims  that
modifications to  their  acid plant resulted in
 "entirely  different  emissions  configurations  and
reduced ambient concentrations" (page  1, Index  5).
However, Kennecott's  "different configuration"
could  readiiW revert back  to  the  same  operating
conditionsYemission rates  as  occurred  in 1973-1974
 through an upset condition in or  a breakdown of
 their  acJUd plant.   During an upset or breakdown
 some or all of  the  gases  normally treated in the
 sulfuric acid plant could be  bypassed  around the
 acid plant and  discharged to  the  atmosphere  untreated,
 Thus,  the  installation or improvement  of a smelter's
 acid plant doe^sfot make high emission rates and
 air quality concentrations unlikely events..
                     -31-

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As discussed earlier, data obtained after ASARCO
began use of its 1000 foot stack in July 1, 1974
cannot be used to calculate an emission limitation
unless and until ASARCO demonstrates that the
stack height represents good engineering practice,
pursuant to Section 123 of the Act.  Until such
time, data obtained prior to July 1, 1974 must be
used.  The 1973-1974 data which EPA used, were
obtained when ASARCO was discharging its off-gases
from the shorter 300 foot roaster/ reverberate ry
furnace stack and 250 foot converter stack.
                   in ASAACO\s .Sol-fun'c yfrci'd fi/anT.'
Kennecott claims that the ASARCO acid plant was
undergoing modification in 1973-1974, and that the
acid plant was in upset conditions on the two days
used by EPA to calculate the emission limitations.
However, Kennecott presents no data to substantiate
these claims or to indicate the magnitude of the
effects on the quantity or location of any increased
emissions.  In addition, ASARCO makes no such
claims in its Petition.  EPA cannot arbitrarily
eliminate data simply because of high source
emissions.  Since acid plant upsets are known to
occur and result in high emission levels, they
represent a valid portion of the data set considered
in setting an emission limit.  EPA cannot base its
actions on unsubstantiated claims, and therefore
rejects this argument from Kennecott.   , _
  < Qfrwers'   *£ fr»»\K*i"Hj JSol-fort'c /9f/d P/d
Kennecott also claims that its smelter was under-
going configuration changes which invalidate the
reliability of data collected during these periods.
On page 2 of Index 5 of the December 11, 1975
Technical Support Document, Kennecott states that
the sulfuric acid plant was converted from single
absorption and 95% sulfur dioxide removal efficiency
to double absorption and 99% efficiency.  This
change by itself would amount to an 80 percent
reduction in emissions from the 100 foot tall acid
plant stack.  However, at the same time the capacity
of the plant was increased from 750 tons per day
to 1960 tons per day or 2.6 times the previous
capacity.  Thus, actual sulfur dioxide emissions
from the sulfuric acid plant stack were reduced by
only about 48% of previous emissions rather than
80% of previous emissions.  In addition, main
stack emissions from the two smelters in Hayden
                    -32-

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were much larger than Kennecott's acid plant
emissions, the Kennecott acid plant emissions
occur at about the same level (elevation) as
fugitive emissions and the Montgomery Reese Ranch
monitor was sited to pick up main stack emissions
rather than fugitive emissions.   Thus, the reduc-
tion in acid plant tail gas emissions at Kennecott
would be expected to have a negligible impact on
air quality measurements at this station and on
the calculation of the emission limitations.

The increase in capacity of the sulfuric acid
plant reduced the emissions from Kennecott's 600
foot stack, since all converter gas could now be
treated in the sulfuric acid plant.  The old acid
plant was not large enough to treat all fluid bed
roaster and converter gases, converter gas was
bypassed and discharged from the 600 foot stack
along with the untreated reverberatory furnace
gases.  However, as discussed previously the
reduced stack emissions would result in lower
ambient concentrations.  Since the smaller percentage
rollback need to achieve NAAQS would be applied to
smaller actual emissions, the net result would be
an SIP emission limit similar to the SIP emission
limit calculated by EPA from the larger air quality
readings caused by larger stack emissions in 1973-
1974.  Thus, the emission limit calculations would
not be significantly affected.
c.. JivsfatHftTien of ConygraiiaS'hpr HoftoJ'*
Finally, Kennecott imfu.ies tnat its tightfitting
hoods have reduced fugitive emissions and therefore
improved the air quality.  However, Kennecott has
again failed to present any data concerning the
magnitude of emission reduction or its effects on
the ambient air quality.  Kennecott claims that
this project was completed in December/1973, thus
implying that none of the hoodsjfinstailed and
operating when the high ambient readings of October
23, 1973 and November 8, 1973 occurred.  However,
as indicated by the enclosures to Mr. Billings'
letter to EPA dated February 15, 1979, two of the
three converter hoods were installed and operational
by September 30, 1973.  Also, the third converter
was being equipped with a hood during October and
November^ 1973^ and was not in service.  Thus the
effect 
-------
        in the ambient data, since the two operational converters
        at the smelter already had hoods installed and operating
        in October and November. 1973.
        4. 6*M*fc**00 £orvT\Vra.TU H CV
        A smelter can always argue that its configuration
        was changing during any given time period.  The
        major question is whether or not these changes
        were significant and whether or not they would be
        expected to have a sustantial impact on the calcula-
        tion of t±C0missio3|imitations.  EPA has concluded
        that Kennecott's contentions are without merit because:

       ^ {.") they are not substantiated by quantitative
            ' modeling or study  results,
                     ftoT'
           2.)they are/i documented,  and

           3^)they would not have a substantial impact
             on the  calculation of the emission
             limitations.    •• j. ~ i
        3. i
-------
          EPA has reviewed the air quality and emission rate
          data provided in Kennecott's Petition for August
          4-5, 1977 when the violatiorifoccurred.   The air
          quality data show that the secondary standard
          (1300 ug/iru;) was violated by a considerable margin
          (1871 ug/m ).  Importantly, however, Kennecott's
          emissions fl273 kg/hr (2806 Ib/hr) 6-hour average]
          which resulted in this air quality violation were
          well below EPA's emission limitation for Kennecott
          of 1750 kg/hr (3850 Ib/hr) S02, and less than one-
          third of the total emissions allowable for both
          Hayden smelters ([3890 kg/hr (8560 Ib/hr)].  Thus,
          one smelter was completely shutdown, Kennecott's
          SO2 emissions were a fraction of the total allowable,
          ana yet a violation of the secondary S02 air
          quality standards occurred.  This condition shows
          the conservative nature of EPA's S02 regulation
          for Kennecott.  A# stated in the Technical Support
          Document to that 'regulation, it had been determined
          from the 1973-1974 data set that "... the highest
          measured value provided a conservative 'best
          estimate' of the concentration likely to be exceeded
          only once a year in each smelter locale"  (pg. 4).
          The data provided in Kennecott's Petition verifies
          this statement.

          Using the new air quality and emission rate data
          provided in the Kennecott Petition, a revised
          emission limitation for Kennecott and ASARCO could
          be calculated.  The emission limit calculation
          using the same methodology as the January 1978
          promulgation would proceed as follows:
                            6            3
Highest 3-hour concentration  :  1871 ug/m   (August 4-5,
1977; Montgomery-Reese Ranch)

Emission reduction needed:  1871 - 1300  =31%
                                1871

Smelter emissions7:  1273 kg/hr (2806 Ib/hr) S02
6From Kennecott's Petition, Appendix A.I.

7From Kennecott's Petition, Appendix B.I.; ASARCO smelter not
 operating.  The emission rate selected is the maximum 6-hour
 average value that could have conceivably caused the violation.
 This results in the most lenient emission limitation when com-
 pared to the other values proved in the Kennecott Petition
 that could have been selected.
                              -35-

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Total allowable emissions to. protect the 3-hour standard:

     (1 - 0.31)(1273)  =  878 kg/hr S02 = 1936 Ib/hr S02
                                    o
Allowable emissions for each smelter :

Kennecott emission limit:

     0.438(878) = 385 kg/hr (849 Ib/hr) S02

ASARCO emission limit:

     0.562(878) = 493 kg/hr (1087 Ib/hr) S02

The ratio of Kennecott1s revised emission limit calculated with
these data  (385 kg/hr) to the emission limit promulgated
January 1978 (1750 kg/hr) is:

                    385   =   0.22
                   175U
                #
          Thus, if Kennecott's emission limitation were cal-
          culated utilizing Kennecott1s own 1977 data(provided
          in their Petition), their  allowable emissi9ns would
          be less than one-fourth of the present emission
          limitation.  Once again,  Kennecott's own data demon-
          strate the  conservative nature of the January, 1978
          regulations.   Indeed, as  stated by Kennecott in
          their written  comments to EPA of December  11,
          1975, "In the  other case, the 3-hour peak  concentra-
          tion of October 20, 1973  [used in the January  1978
          EPA regulations], the allowable emissions  indicated
          may not be  sufficient to  prevent violations  [of the
          air quality standard[ without a supplementary control
          system.1'9   If  Kennecott Relieves that EPA's limit
          is not sufficientira'protect standards, it's difficul
          to understand  how they can  recommend a di££oront
          emission limit in Appendix  G to their Petition. 4k
          ir 1cm ntrinient    (See  discussion of Appendix G
          in Section  VII.K.  of this report).
 bSee  Technical Support Document for Arizona Smelter Regula-
  tions  (November 1977) and Section VII.D.  of this  report for
  basis  of apportioning.

 9 Index  5,  page 4.



                               -36-

-------
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F.   The Running 6-Hour Averaging Period Used to
     Determine Compliance with the Emission Limitation
     (KCC):

     On pages 4-6 of its Petition Kennecott claims that
     the 6-hour averaging period makes compliance with
     the emission limitation technologically and econo-
    . mically infeasible, and therefore unreasonable.
     Kennecott claims that it would either have to
     increase sulfur capture from its present 89 percent
     to 99 percent, or reduce its production by 11.4
     percent in order to comply with the emission
     limitation on the basis of a running 6-hour averaging
     period.

     The running 6-hour averaging period will ensure
     attainment and maintenance of the 3-hour NAAQS for
     sulfur dioxide, and compliance with emission
     limitations using a running 6-hour averaging
     period is reasonable.

     As previously discussed in Section V, the Clean
     Air Act requires that EPA establish emission
     limitations which are sufficient to attain and
     maintain the NAAQS, regardless of whether or not
     the limitations are technically or economically
     feasible.  The issues of technical and economic
     feasibility can be considered in the enforcement
     process when a timetable for compliance with
     emission limitations is established.  In the case
     of nonferrous smelters, a special smelter specific
     Section 119 was added to the Clean Air Act on
     August 7, 1977.  It provides a specific mechanism
     through which to consider technical and economic
     feasibility prior to requiring compliance with the
     SIP sulfur dioxide emission limitations.  However,
     the SIP sulfur dioxide emission limitation necessary
     to attain NAAQS remains in effect, and the smelter
     remains responsible for compliance with the limita-
     tion solely through1 the use of constant controls
     upon expiration of the NSO(s).  See Section III of
     this report for a more detailed discussion of
     NSOs.

     As stated in the preamble to the January 4, 1978
     EPA regulations (43 FR 757, column 2, first com-
     plete paragraph):
                         -38-

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     "Since  the  secondary air quality standard  for
     SO-,  is  based on a three-hour average,  a  short
     time averaging period for the SIP emission
     limit is required to protect this short  term
     air  quality standard.  Thus  a long averaging
     period  (such as those suggested by some
     commentators) for the SIP emission limit
     would provide no assurance that short term
     NAAQS would be protected. For example,  if a
     daily averaging period were  used, stack
     emissions could be large during part of  the
     day, violating the secondary (three-hour)
     NAAQS,  while production could be decreased
     for  the remainder of the day such that the
     emission limit would be met  on an average
     basis.   For this reason, the moving six-hour
     averaging period cannot be relaxed without
     defeating the basic purpose  of the secondary
     NAAQS.   In the Administrator's judgment, a
     moving six-hour averaging period is sufficiently
     stringent to protect the S02 air quality
     standards and is the shortest period which
     can be reasonably used for copper smelters to
     determine compliance with the SIP emission
     limit."

EPA reaffirms these statements as part of its
response to the Kennecott Copper Petition. Since
Kennecott has failed to provide any quantitative
study results to  show that an alterative averaging
period will ensure protection of the  3-hour standard
for sulfur dioxide, EPA rejects Kennecott1s request
for a different averaging time.

On page  5 of its  Petition Kennecott also claims
that the 6-hour averaging period is inadequate to
mask or  dampen emission  fluctuations, and that it
should be lenthened.  EPA pl£tted*l/2 hour and 6-
hour amid oion gato  average^3iHHiBtaiM» for the
reverberatory furnace stack  at Kennecott, Hayden,
Arizona.  These plots show that the 6-hour averaging
period significantly reduces  the emission fluc-
tatuions which occur using 1/2 hour averages.  An
example  of this  "damping" effect can  be seen from
the plot of  July  30, 1977.   Because of this demon-
strated  "damping"  effect an
-------
show that an alternative averaging period will
ensure prfltoection of the 3 -hour secondary standard
for sulfur dioxide,  EPA reaffirms the 6-hour
averting period used in the January 4,  1978 promul-
gation and rejects Kennecott's request for a
longer averaging period.

In its reconsideration of the 6-hour averaging
period, EPA discovered an issue which was not
raised by any of the smelters, but which needs to
be clarified.  This issue involves whether or not
multiple violations of the 6-hour emission limitation
can be overlapping.  It is clear that compliance
with the emission limitation is to be determined
by examining a six-hour average beginning each
clock hour.  Thus, there will be 24 checks for
compliance every day.

What happens if a violation is detected?  Can two
or more violations occur which overlap, or must
multiple violations be non-overlapping?   If multiple
violations can overlap it would be possible to
have 19 violations of the 6-hour emission limit
within a 24-hour period.  If multiple violations
must be non-overlapping, then there could never be  .
more than 4 violations of the 6-hour emission
limit within a 24-hour period.   It is EPA's belief
that multiple violations should  not overlap.
Overlapping violations  could  result in  "double
jeopardy" since very high emissions during  a  one
hour period could cause up  to 6  violations  of the
emission  limit if overlapping violations  were
allowed.  Therefore in  determining the  number of
multiple  violations, they must be non-overlapping
6-hour periods.  After  selection of the first
violation,  any other violations  shall not overlap
with  this  first  six-hour period.  This  change will
be  added  to  the  regulations at 40 CFR 52.125
 (d)(6)(i)  as  subparagraph (e), as  follows:
 40 CFR 52.125(dM:   Multiple violations  of para-
 graphs (d)(l)  aria (d)(2)  of this  section may not
 contain any common hourly sulfur  dioxide readings.
                     -40-

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G.   Consideration of Converter Slag as a Final Discard
     Product ( PD ) :
                      .                    •         . /
     On page 6 of £to Supplemental Comments to +> ITS
     original Petition, Phelps Dodge contends that
     EPA's emission limitation calculation for the New
     Cornelia smelter (located in Ajo, Arizona) considers
     converter slag as a  final discard product.  Phelps
     Dodge states that in actuality converter slag is
     recycled to the reverberatory furnace.

     EPA has re-examined  its calculation sheets for the
     New Cornelia smelter,  and agrees with the Phelps
     Dodge contention.  Converter slag should not be
     considered as a final  discard product for this
     smelter.  This change  in the "3-hour based" emission
     limitation calculations causes the emission limita-
     tion for the New Cornelia smelter to increase
     slightly (4.9 percent) from 75.7 tons per day
     sulfur dioxide to 79.4 tons per day, or from 2870
     kg/hr (6310 Ibs/hr)  to 3010 kg/hr (6620 Ibs/hr).
     The revised 3-hour calculation sheet for the New
     Cornelia smelter is  attached.

     However, EPA then discovered that the emission
     limitation based on  the highest 24-hour ambient
     reading resulted in  a  more stringent emission
     limitation than the  recalculated  "3 -hour based"
     emission limitation.  Further review of the 24-
     hour calculation revealed an error in the calculation
     in the average 24-hour concentration.  The data
     from the day in question  (June 7, 1974) contained
     only 23 hourly readings rather than 24 hourly
     readings, yet the sum  of the hourly concentrations
     had been divided by  24 rather than 23 .  Correction
     of this error resulted in a higher ambient air
     quality reading  (1042  ug/m3 rather than 999 ug/m3)
     and a greater degree of control necessary to
     attain the NAAQS  for sulfur dioxide  (65 percent
     rather than 63 percent).  The resulting emission
     limitation based on  the highest 24-hour reading is
     75.0 tons per day sulfur dioxide, or 2840 kg/hr
     (6250 Ibs/hr).  This is virtually identical to the
     January 4, 1978  emission  limitation which was 75.7
     tons per day sulfur  dioxide, or 2870 kg/hr (6310
                          -41-

-------
Ibs/hr).  The revised "24-hour based" calculations
are attached.

EPA will make the appropriate changes to the
emission limitation for the Ajo smelter.
                      -42-

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AJO - 3 hour

Date:  11 November 1973
Monitoring Site:  South Tailings Pond
Site Operator:  Phelps Dodge
Hourly Concentrations:  1.04, 2.18, 1.74 ppm
Average Concentration:  1.65 ppm x 2620 = 4323 ug/m

Percent Reduction Required:  100(4323-1300) = 69.93% or 70%
                                  4323

Emissions:

                           Reverb      Blister
                           Slag        Copper      Acid
[(363)(.300) + (290)(.370)]-[(525)(.01) + (190)(.025) + (32)(226.4)]


= [108.9 + 107.3]-[5.2 + 4.8 + 73.9]
= 132.3 tons sulfur

Emission Limit Calculation:

(64) (132.3)(1.00-.70) = 79.4 tons/day S00
(32)                  - 6620 Ibs/hr     ^
                      = 3010 kg/hr
                              -43-

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AJO - 24 hour
Date:  7 June 1974 (0000-2300)
Monitoring Site:  Oxidation Pond
Site Operator:  EPA                                         3
Average Concentration:  9.15 = 0.3978 ppm x 2620 = 1042 ug/m
                        ~~
Percent Reduction Required:  (100)(1042-365) = 64.97% or 65%
                                   1042

Emissions:* Input =  (641) (.308) = 197.4 tons sulfur
     Emissions    =  (Input Sulfur )(% Fugitive + % Reverb +
                     % Converter)
                  =  (197. 4)(. 1525 + .2316 +  .1582) = 107.1 tons
                     sulfur

Emission Reduction Required:

 (64)(107. !)(!-. 65) = 75.0 tons/day S02
 (31)               = 6250 Ibs/hr S07 ^
                   = 2840 kg/hr SO^

 *From  10/21/74  Phelps Dodge  Letter
                                .44-

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H.   The Effect of Section 123 of the Clean Air Act
     Iconcerning Stack Heights and Other Dispersion
     Techniques) on the Emission Limitation Calcula-
     4— ^ A •^T^^^^^iT/'* n i^"^^7^~~^^^*^^ T<»*\~ \  ^^™^••    - • • • ~ M^*—^- •_  -   _ .
     tions (ASARCO and PD ) :
     1.
     On Page 31 Of its Petition, Phelps Dodge implies
     that Section 123 of the Clean Air Act might affect
     the calculations performed by EPA to determine the
     emission limitations for the three Phelps Dodge
     smelters.  EPA does not agree with the Phelps
     Dodge implications.  The main stacks at Ajo (1
     stack), Douglas (2 stacks) and Morenci (2 stacks)
     that are used today were all installed and operated
     prior to the Clean Air Act Amendments of 1970.
     These stacks were in use during 1973-1974 when EPA
     collected the ambient air quality data for sulfur
     dioxide upon which the regulations are based.
     Therefore, Phelps Dodge is entitled to and has
     received -"credit" for all of its existing stacks
     in the determination of the emission limitations
     for its three smelters in Arizona.

     Phelps Dodge has not received credit, nor is it
     entitled to any such credit, for the use of supple-
     mentary control systems (SCS, a dispersion technique)
     at its three smelters .  Phelps Dodge Corporation
     was not operating SCSd at its smelters prior to
     passage the Clean Air Act Amendments of 1970, and
     therefore it is not entitled to have its degree of
     emission limitation reduced because of operation
     of an SCS.  Furthermore, such "credit for SCS" has
     not been allowed by EPA in calculation of the
     Phelps Dodge emission limitations.  The company
     was not operating SCS when the ambient air quality
     data for sulfur dioxide were collected in 1973 and
     1974.  Since these data were used to calculate the
     emission limitations, Phelps Dodge has not received
     credit,. for its SCS.  Therefore, the appropriate
     credit>[under Section 123 has been given to Phelps
     Dodge by the data collected in 1973 and 1974.
     On pages 17-18 of its Petition, ASARCO argues that
     EPA should recalculate the emission limitation for
     ASARCO because EPA  "did not consider any portion
     of the stack presently used," and because ASARCO
     has not had an opportunity to demonstrate what
     stack height represents good engineering practice
                         -45-

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          at  its  Hayden Smelter.   EPA  does not  agree with
          ASARCO's  contentions.

          First,  some portion of  the 1000 foot  stack has
          implicitly been considered in the  emission limi-
          tation  calculations because:

               The  roaster/reverberatory furnace  emissions
               of 139 tons sulfur per  day on October 20, 1973
               were emitted from  the old 300 foot tall  roaster/
               reverb stack,

               The  converter emissions of 84 tons sulfur per
               day  on October 20, 1973 were  emitted
               primarily from the old  250 foot  tall converter
               stack, since these emissions  were  mainly
               converter gases  which were bypassed around  the
               sulfuric acid plant, and

          *.    The  sulfuric acid  plant tail  gases could have
               accounted for a small portion of the sulfur
               from the converter emissions  described  in No. 2
               above, and these emissions were  dis-
               charged from the 86 foot tall sulfuric  acid
               plant stack.  The  emissions  from the sulfuric
               acid plant stack were not specified by  ASARCO.

          Assuming  that all 84 tons sulfur  per  day of  the
          converter emissions were emitted  from the 250 foot
          converter stack, an approximation of  the equivalent
          single stack height would be:

          [   139   ] (300 feet) + [   84    ] (250 feet)  =
          [139 + 84]              [TJ9  +~84]

          187.0 + 94.2.= 281.2 feet

          Therefore 281.2 feet of the  1000  foot stack  fe*w»has
          been implicitly considered in the determination of
          ASARCO's  emission limitation since the ambient moni-
          toring data reflects the effect of emissions from
          the"equivalent stack height upon the  ambient
          monitors.
10The 281 feet equivalent single stack height at ASARCO,
  Hayden, Arizona, is automatically "grandfathered" under the
  provisions of Section 123.  In other words, ASARCO receives
  "credit" for this stack height, since the 300 foot and 250
  foot stacks were constructed and used prior to 1970.
                              -46-

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 Second, EPA  cannot  recalculate ASARCO's emission
 limitation until  such  time  as ASARCO demonstrates
 that  a  stack height greater than  281.2 feet
 represents good engineering practice stack height.
 Until this demonstration is made  in accordance
 with  Section 123(c) of the  Clean  Air Act, EPA will
 consider  that 281.2 feet represents good  engineering
 practice,  and the emission  limitation  for ASARCO
 will  not  be  changed.  In accordance with  Section
 123(c)  ASARCO may make this demonstration by
 showing either:

4|f.    That two and one  half  times  the height  of  the
      source  is greater than 281.2 feet, or

 ^.    That a  stack height in excess of  281.2  feet
      is necessary to prevent stack emissions from
      causing "excessive concentrations of any air
      pollutant in the  immediate vicinity  of  the
      source  as a result of  atmospheric downwash,
      eddies  and wakes  which may be created by the
      source  itself, nearby  structures  or  nearby
      terrain obstacles."

 ASARCO's  emission limitation will not be  changed
 on the basis of Section 123 until ASARCO  has made
 the required demonstration.  Since EPA must  promul-
 gate regulations to implement Section 123, ASARCo^
 cannot make such a  demonstration until these
 regulations are promulgated.  EPA proposed regulations
 to implement Section 123 on January 12,  1979 (44
 FR 2608).  When the regulations have been finalized,
 EPA will consider  any demonstration by ASARC^ to
 define all or part  of its  stack as GEP.   If "at
 that time EPA determines that more than 281  feet
 of ASARCO's stack  is GEP,  then the Hayden emission
 limits for ASARCfi.  and Kennecott will be revised
 accordingly, so that proper credit for the additional
 stack height is  reflected  in these emission limita-
 tions.  EPA's  failure to promulgate regulations
 implementing Section  123 has not placed ASARCO in
 jeopardy because ASARCO  is not presently required
 to be in compliance with its existing emission
 limitation.
                      -47-

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The Use of Monthly Average Sulfur Input and Emission
Data versus Daily Average Sulfur Input and Emission'
Data to Calculate Emission Limitations (Magma):

On page 1-3 of its Petition, Magma Copper requests
that its emission limitation be recalculated based
upon monthly average sulfur input and emission
data for October, 1973.  The company claims that
this procedure is a more accurate estimate of
emissions which influenced the 3-hour ambient
reading of 6078 ug/m3 than the daily sulfur input
and emission data used by EPA to calculate the
emission limitation for Magma (promulgated by EPA
on January 4, 1978).  The use of monthly data
requested by Magma would result in an increase in
the allowable emission limitation from 9000 kg/hr
(19,850 Ibs/hr) to 9590 kg/hr (21,150 Ibs/hr), or
an increase of 6.6%.

In an  attempt to  justify to EPA that monthly
rather than daily sulfur balance data should be
used to determine smelter emissions and to calculate
an emission limitation, Magma argued that  1) some
of the sulfur input to the  smelter on a given  day
could  remain in  the smelter for  several days
before it was emitted, 2) that  a, better estimate
of daily sulfur  emissions could  be obtained by
averaging  sulfur  input for  several days prior  to
the date of the  high  ambient air reading,  and  3)
that the October,  1973 monthly  average sulfur
input  would be  "substantially the  same as"  a ten
day average prior to  October 12, 1973.  EPA does
not agree  with  Magma's arguments.

While  EPA  agrees that some  of the  sulfur  entering
 a smelter  on  a  given day may not be  emitted on
 that day,  Magma has   not presented any data on how
 to  account for  this  effect.  The only way to
 overcome this  difficulty is to  measure emissions
 directly and continuously.   Since  these  continuous
 emission data are not available,  EPA cannot take
 this  effect into account.

 It should be emphasized that the use of  continuous
 emission monitoring data would provide a better
 estimate of daily smelter emissions than the
 sulfur balance type data which all of the smelters
                     -48-

-------
provided to EPA.  However, continuous emission
monitoring data is not available from the smelters
for the time period of July 1973 to November 1974
when EPA collected extensive ambient air quality
data.  Emissions and ambient air quality data are
necessary to perform these emission limitation
calculations.  In the absence of actual emission
measurements EPA used emission estimates based on
sulfur balance measurements at each smelter.  The
smelters submitted these data to EPA for the days
on which high readings were obtained.  EPA then
used these data to calculate emission limits.

Magma's recommendation that ten day sulfur input
and emission data be used to calculate emissions
which influenced the October 12, 1973 high 3-hour
reading cannot be accepted because
comrinointj  anjmnrntn Nigim has provided no convincing
arguments as to why a ten day average is a better
representation of daily emissions than a one day
average ,
Neither has/itnat  a monthly  average "Is  a better
estimate  of  emissions which influenced the October
12,  1973  high - 3-hour  reading than  is the daily
sulfur input and  emission data used  by EPA.

EPA  does  not agree with Magma Copper's arguments
that monthly average  sulfur emissions  provide a
better estimate of emissions which influenced a 3-
hour ambient air  reading than do  daily average
sulfur emissions.  In this  specific  case  it  is
clear that the emissions which occurred from
October  13-31, 1973  could not possible have  influ-
enced the 3-hour  reading on October  12, 1973.
Thus the emissions from 19  of the 31 days in
October  (or  61 percent) could not have influenced
the  3-hour reading,  yet they play a  role  in  determining
the  ^flter's emission  rate under Magma's proposed
method.   Further,  it is unlikely  that emissions
which occurred more  than three days  earlier  than
October  12,  1973  had any impact  at  all on the
October  12 high  reading. Thus the  emissions from
additional 9 of  the  31  days in October 1973  (or  an
additional 29 percent)  probably  had no impact  on
the  October  12,  1973 high  reading,  yet they  also
play a  role  in determining  the  smelter's  emission
                     -49-

-------
rate under Magma's proposed method.  Thus under
Magma's scheme the smelter emission rates which
"influenced the high reading" are 90 percent (61 +
2^percent) determined by emissions which had
absolutely no impact on the high reading.  This
makes no sense from a technical standpont.  The
emissions which occurred on the day of the high
reading (October 12, 1973) are the most likely to
have influenced the high 3 -hour reading and should
be used to represent smelter emissions.  EPA used
daily emission estimates provided by the smelters
in its calculation of smelter emission limits for
its January 4, 1978 regulations.  The EPA method
is preferable to the method proposed by Magma
because it is a better representation of the
emissions which influenced the high reading than a
monthly average.

Because there is no sound technical basis for use
of monthly data rather than  daily  data and to
maintain  regulatory consistency  for the  Arizona
smelters, EPA will continue  to use the October  12,
1973 daily emission rate of  567  tons of  sulfur  to
calculate the emission  limitation  for Magma.  This
emission  rate was provided to EPA  by Magma by
letter  dated May  27,  1975.

In  summary Magma  has  requested  that  its  emissions
be  estimated using  a  monthly average without
providing EPA with any justification that this  is
a better  technique  than the  daily  emission estimates
which  Magma  itself provided to  EPA.   In  fact  the
daily  emission esfjliifees used by EPA are the  best
 available estimates of emissions which influenced
the high 3-hour readings at the Arizona  smelters
 in  1973J974.
         l
 Despite EPA's rejection of Magma's request to use
 a monthly average emission rate, EPA does recognize
 that the daily smelter feed rate could result in
 an inaccurate determination of emissions because
 of "hold-up" in storage bins.  If Magma were to
 provide EPA with the daily feed rates to the
 smelter for several days prior to the violation,
 EPA would consider using a multi-day average
 rather than the present 1-day emission estimate.
 In this particular instance, EPA believes that the
                      -50-

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use of a one day emission estimate is a better
reprsentation of the emissions on October 12,  1973
than is iponthly average emission estimate.  This
is primarily due to fact that smelter emissions
can fluctuate significantly over the course of a
month.  Thus a monthly average emission estimate
is potentially less representative of actual
emissions on a single day than a daily estimate of
emissions on that day.  Since Magma has stated
that individual daily data for October, 1973 are
not available, it is not possible to determine the
daily operating fluctations which occurred during
this month.
                     -51-

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                  of
3-    Recalculation the Emission Limitation for Inspiration
     Consolidated Copper Using a New Calculation Method
     Suggested by Inspiration (ICCC):

     On pages 1 and 2 of Appendix A of their Petition
     Inspiration Consolidated Copper Company stated
     that the data used by EPA to calculate the emission
     limitation for this smelter was incorrect and that
     EPA has used an incorrect technique to calculate
     the emission limitation.

     EPA used a figure of 15.07 percent for the sulfur
     content of the smelter feed on March 11, 1974.
     This number was provided to EPA by the Company
     by letter dated July 15, 1975.  Inspiration now
     claims that this data is incorrect and that the
     correct figure for sulfur content should be 19.66
     percent, based on the monthly average sulfur con-
     tent for March,  1974.  EPA will use the figure of
     19.66 percent to recalculate the emission limitation
     for Inspiration.  EPA also used a figure of 5.13
     percent of input sulfur to calculate the amount of
     sulfur which leaves the smelter in the reverberatory
     furnace slag.  Data presented by Inspiration in
     Appendix C of Exhibit A of its Petition indicates
     that 5.46 percent of the input sulfur left the
     smelter in the reverberartory furnace slag during
     March, 1974.  EPA will use this more recent figure
     of 5.46 percent to recalculate the emission limi-
     tation for Inspiration.

     Inspiration also attacked EPA's method for deter-
     mining the emissions from the smelter, since this
     method ignores "the technology of smelting."  In-
     spiration instead suggested that EPA use an alter-
     native method to calculate the smelter's emissions.
     Inspiration presented example calculations of
     smelter emissions based on the highest 3-hour and
     highest 24-hour ambient air readings for sulfur
     dioxide:  March 12, 1974 (3-hour violation) and
     November 10, 1973 (24-hour violation).  The
     Inspiration method of emission determination
     involves three steps and several assumptions.
     The three steps are:

     1.   Calculate reverberatory furnace emissions
          using the amount of material charged to the
          furnace and assuming that 25 percent of the
                         -52-

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     of the sulfur in the feed is emitted from the
     furnace (the moisture content and sulfur
     content of the feed are known),

2.   Calculate converter emissions using the
     number of ladles of matte charged to the
     converter and assuming that matte is composed
     entirely of copper sulfide (ClE^B) and iron
     sulfide (FeS) (the copper content of the
     matte is known), and

3.   Add reverberatory furnace and converter
     emissions.

The total  smelter emissions and the highest
measured air quality  reading  are  then used to cal-
culate the emission limitation for the  smelter
using the  proportional rollback model.

The assumptions  that  25  percent  of the  sulfur in
the reverberatory furnace feed is emitted from the
furnace, and that matte  is composed entirely of
copper  sulfide  and iron  sulfide*appear  fn be
reasonable assumptions  (pages 3-26 and  3-83  of
"Background Information  for New  Source  Performance
Standards:  Primary Copper,  Zinc, and Lead Smelters,
volume  I:   Proposed Standards,«  EPA-450/2-74-002a,
October 1974J.   However, there is no  readily
apparent means to check the validity  of these
assumptions at Inspiration's smelter.   Therefore,
their use  to calculate Inspiration's  emissions is
questionable.

 Superficially,  the method of calculation proposed
by Inspiration could be acceptable.   However,
 further examination of the method reveals that it
 neglects  "the technology of smelting" in two
 important areas:

 1    It neglects the fact that some of the  input
      sulfur leaves the  smelter in the reverberatory
      furnace slag, and

 2    It neglects the fact that a substantial
      amount of  converter slag is recycled to the
      reverberatory furnace.
                      -53-

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Neither of these factors should be neglected when
attempting to determine the emissions from the
smelter using the method suggested by Inspiration.
Neglecting either of these points can lead to an
overestimation of the amount of material emitted
from the smelter, and thus lead to an emission
limitation which is less stringent than necessary
to protect the NAAQS for sulfur dioxide.

Inspiration's method of calculating smelter emissions
neglects the sulfur which leaves the smelter in
the reverberatory furnace slag.  Information
submitted by Inspiration in Appendices 2 and 4 of
Exhibit A of their Petition indicates that 4.83
percent of the input sulfur left the smelter in
the reverberatory furnace slag during the month of
November 1973, while 5.46 percent of the input
sulfur left in the slag during March, 1974.  In
addition Appendix 1 of the Petition indicates that
during the March 11, 1974 "c" shift  (midnight
3/11/74 to 0800  3/12/74) 15 pots of furnace slag
were extracted from the furnace, while  15 ladles
of matte were extracted.  Thus the quantity of
slag extracted from the furnace  is not  negligible
in comparison to the amount of copper bearing
matte which is extracted from the furnace.
Neglecting the sulfur  losses in  the reverberatory
furnace slag on  March  12, 1974  (the date of the
highest 3-hour sulfur  dioxide reading)  could
result in emissions which are 5.46 percent too
high.  This would  lead to an emission limitation
which is also 5.46 percent  too high  to  insure
protection of the NAAQS.

Inspiration's method  for  calculating smelter
emissions also neglects  the  fact that a substantial
amount of converter  slag  is  recycled to the  rever-
beratory  furnace.  This converter slag  undoubtedly
contains  some  sulfur which  would not be emitted
from  the  converters  at this  time.   Inspiration's
method neglects  converter slag  recycle  and  assumes
that  all  sulfur  entering the converters is  emitted
from  the  converters  during  the  slag  blow or  copper
blow  cycles  of  that  converter.   Using this method,
converter sulfur emissions  will  be  overestimated
because  any sulfur which leaves  the  converter in
the  converter slag is  assumed to be  emitted.
                     -54-

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This overestimate of emissions results in an
emission limitation which is too large to protect
NAAQS.  The amount of converter slag recycled from
the converters is not negligible in comparison
with the amount of matte added to the converters.
Data submitted by Inspiration in Appendix 1 of its
Petition indicates that during the March 11, 1974
"C" shift 12 ladles of converter slag were returned
to the reverberatory furnace, while 15 ladles of
matte were added to the converters.

EPA does not have data on the amount of sulfur
that leaves the converters  in the converter slag,
so it cannot estimate the extent to which the
converter emissions are overestimated by Inspiration s
emission calculation method.

In addition,  Inspiration's  own  calculations  (presented
to EPA by the  Company in Exhibit A  to  its Petition)
indicate that:

1     During  the 8-hour  period from  midnight March
      11, 1974  to  0800 March 12,  1974  (which includes
      the highest 3-hour ambient air quality reading)
      23.7 percent more  sulfur was  emitted from the
      smelter than entered the smelter,  and

2.    During the 24-hour period from midnight,
      November 9,  1973  to midnight,  November 10,
      1973  (which includes the highest 24-hour
      ambient air quality reading)  12.3 percent
      more  sulfur was emitted from the smelter than
      entered the smelter.

 The calculations supporting these figures are in-
 cluded at the end of this section.   EPA recognizes
 that over "short" periods of time (such as 8 hours
 or 24 hours) it is clearly possible for more
 sulfur to be emitted from a smelter than enters
 the smelter.  However, over long time periods
 (such as a week, a month or a year) the amount of
 sulfur leaving the smelter must be equal or nearly
 equal to the amount of sulfur entering the smelter.
 In other words, periods when sulfur emissions
 exceed the sulfur feed must be balanced by equal
 periods when sulfur emissions are lower than the
 sulfur feed,  ntmovofe*. since daily sulfujr dioxide
                      -55-

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emissions can fluctuate drastically,  the daily
emission estimates are a better estimate* of
actual emissions on a given day than a daily
emission estimate obtained by averaging 30 days
worth of emissions as discussed in greater detail
in Section VIII.I.  The purpose of estimating
emissions is to estimate the emissions which
influenced the high ambient air quality reading.
For this purpose |ghort (less than 3 days and
preferably 1 day) averaging period is a better
approximation of these emissions than a long (1
week or 1 month) averaging period.

When considered together, the fact that Inspiration's
emission calculations:

1.   Assume that 25 percent of the input  sulfur is
     emitted from the reverberatory furnace,

2.   Assume that matte is composed entirely of
     copper sulfide and iron sulfide,

3.   Neglect sulfur losses  from the smelter in  the
     reverberatory furnace  slag,

4.   Neglect sulfur losses  from the converters  in
     the converter slag,  and

5.   Result  in  sulfur emissions that  are  12 to  24
     percent larger than  sulfur feed  to the
     smelter;

indicate that there  are  serious questions concerning
the  validity of these calculations.   At the present
time,  EPA  cannot accept  the use of Inspiration's
method of  emission calculation because of these
questions.   Furthermore,  EPA must use consistent
calculation techniques and assumptions for the
emission limitation determinations for all of the
Arizona smelters.   EPA is not convinced that
 Inspiration's  method is  appliable to  all of the
other  smelters  in Arizona.

EPA will continue to use it original  calculation
 technique  for emissions  from the  Inspiration
 smelter.   This technique involves three steps:
                     -56-

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1.   Determine the sulfur input to the smelter
     from the daily smelter feed rate and the
     sulfur content of the feed,

2.   Determine the sulfur losses in the reverberatory
     furnace slag from the sulfur feed rate and
     the percent of input sulfur lost in the slag,
     and

3.   Determine the smelter emissions by subtracting
     the sulfur lost in the reverberatory furnace
     slag from the sulfur input to the smelter.

As indicated earlier in this discussion Inspiration
provided EPA with new data concerning the sulfur
content of the smelter feed material and the per-
centage of the sulfur feed to the smelter which
leaves the smelter in the reverberatory furnace
slag.  EPA has used these new data to recalculate
smelter emission limitations based on the highest
3-hour and 24-hour ambient air  readings.  The cal-
culation sheets for each are attached.  The  3-hour
reading yields an emission limitation of 49.5
tons/day sulfur dioxide while the 24-hour reading
yields a limit of 55.9 tons/day aulfur dioxide.
The 3-hour limit is still the more stringent
emission limitation, but this limitation has now
toe.ILK increased from 38.1 tons per day to 49.5 tons
per day sulfur dioxide.  This is  an  increase of

100f49.5-38.1] = 29.9% = 30% from the
   38.1

previous EPA limit promulgated  on .January 4,  1978.
EPA will change the emission limitation  for
Inspiration  accordingly.

For comparison purposes,  the following table sum-
marizes the  3-hour  and 24-hour  emission  limitations
for sulfur dioxide  emissions from Inspiration.
The second row of  limits  represents  the  limits
calculated by Inspiration using its  emissions  and
a proportional rollback  calculation:
                     -57-

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Sulfur Dioxide
Emission Limits     24-Hour        3-Hour
For inspiration     (11/10/73)     (3/12/74)

EPA (1/4/78)        44.9 TPD       38.1 TPD
ICCC (2/2/78)       66.0 TPD       68.3 TPD
EPA (11/15/78)      55.9 TPD       49.5 TPD
                      -58-

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          Inspiration Consolidated Copper Company,
                     Inspiration,  Arizona
            Comparison of Sulfur Input and Sulfur
      Output Using Inspiration's Calculation Technique


I.    Using Data from Exhibit A of the Petition,  "Recalculation
     of Emission Limitation Based on March 12,  1974 - 3-Hour
     Average Reading":

     A.   Sulfur Feed to Smelter, Midnight-March 11, 1974
          to 0800-March 12, 1974 (8 hours):

          196.97 tons/24 hours  =  65.66 tons/8 hours
          Three 8 hours/24 hours

     B.   Sulfur Emitted from Smelter, Midnight-March 11,
          1974 to 0800-March 12, 1974  (8 hours):

          243.71 tons/24 hours  = 81.24 tons/8 hours
          Three 8 hours/24 hours

     C.   Percentage Difference:

           (100 )f81.24-65.66^.=  (100)15.58  =  23.7%
               65.66              65.66

          more sulfur  emitted  from the smelter than entered
          the smelter  in this  8-hour period.

 II.  Using  Data  from Exhibit A of the Petition,  "Recalculation
     of Emission  Limitation  Based on November 10,  1973  -
     24-Hour Average Reading":

     A    Sulfur  Feed to Smelter, Midnight-November 9,  1973
           to Midnight-November 10,  1973  (24 hours):

           209.79  tons/24 hours

     B    Sulfur Emitted from Smelter, Midnight-November 9,
           1973  to Midnight-November 10,  1973 (24 Hours):

                     Converter      Converter
           Reverb    "C" Shift    "A" and "B" Shift

           52.45  +  39.43     +  143.63      = 235.51 tons/24 hours
                               -59-

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C.   Percentage Difference:

     (100H235.51-209.79) = (1QO)(25.72) = 12.3%
            209.79             209.79

     more sulfur emitted from the smelter than entered
     the smelter in this 24-hour period.
                          -60-

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MIAMI - 3 hour

Date:  12 March 1974
Monitoring Site:  Jones Ranch
Site Operator:  EPA
Hourly Concentrations:  4.60, 3.50, 2.90 ppm         3
Average Concentration:  3.6667 ppm x 2620 = 9607 ug/m

Percent Reduction Required:   (100)(9607-1300) =  86.47% or 86%
                                   9607

Emissions:      Feed    %S
                (951)  (.1966)* =  187.0        Sulfur feed
           -   (187.0)(.0546)* =  -10.2        Slag Losses
                                 176.8  tons  sulfur emitted

Emission  Limit Calculation:

 (64)(176.8)(l-.86) = 49.5  tons/day S02
 (32)              = 4130  Ibs/hr
                   = 1880  kg/hr

 *From Appendices 2  and 3 of Exhibit A of Inspiration's  Petition
 dated February 2,  1978.
                                -61-

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MIAMI - 24 hour

Date:  10 November 1973 (10 November 2200 to 11 November 2100)
Monitoring Site:  Jones Ranch
Site Operator:  EPA                                         3
Average Concentration:  23.25 = 0.969 ppm x 2620 = 2539 ug/m
                          24

Percent Reduction Required: (100)(2539-365) = 85.62% or 86%
                                 2539

Emissions:   Feed   %S
             (1078)(.1947)* = 209.9     Sulfur feed
            -(209.9)(.0483)*= -10.1     Slag losses
                              199.8 tons sulfur emitted

Emission Limit  Calculation:

(64)(199.8)(l-.86) =55.9  tons/day SO?
(32)               =  4660  Ibs/hr
                   =2120  kg/hr


*From Appendices 4 and  5 of Exhibit A of Inspiration's Petition
dated February  2, 1978.
                               -62-

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    K.   The Statistical Modeling Approach to Emission Limita-
         tion Calculation  (KCC):

         On pages  9-11  of  its  Petition  Kennecott  argues that
         EPA should  use a  statistical model to calculate
         smelter emission  lindTations rather than  the propor-
         tional model contained in  40 CFR 51.13(e).

         Throughout  the discussion  of the statistical modeling
         approach  contained in Appendix G to Kennecott's
         Petition, Kennecott argues that the variability
         inherent  in a  smelter's SO- emission rate  should be
         considered  in  the derivation of an ultimate emission
         limit.  A smelter's fluctuating emission rate,
         Kennecott argues, represents an issue of technological
         feasibility with  respect to meeting-, this emission
         limit.  Since  EPA's emission limit   did not
         specifically take account of the  fluctuating  nature
         of a smelter's emissions and since Kennecott  cannot
         meet EPA's  emission limit, Kennecott feels the
         EPA emission limit goes beyond the requirements  of
         the Clean Air  Act (CAA).

         EPA maintains  that, under Section 110,  issues of
         technologial (and economic) feasibility are not
         germane to  the process of establishing  an  emission
         limit  designed for attainment  and maintenance of
         the standards.  Various court  decisions and provisions
         of the 1977 Clean Air Act Amendments  support  this
         position  (see  discussion in Section V).

         The key parameters utilized in the development  of
         an ultimate emission limit are the air  quality
         standards,  a source's mass emission  rate,  the air
         quality concentrations resulting from those emissions,
         and the dispersion characteristics endemic to the
         locality.  Other features, however,  are not relevant
         to  the derivation of an emission limit designed to
         protect the standards  ;  for example,  a smelter's
         general configuration, process equipment,  control
         technology, concentrate feed properties, emission
          fluct)i*aions,  etc., are technical features unnecessary
          for  and irrelevant to the establishment of an ultimate
         emission limit.
1:L43 Federal Register 755.

12Except to the extent that they indirectly affect the
  source's mass emission rate.
                              -63-

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         i.
         Kennecott states on pages 5 and 6 of its Petition
         that their Hayden smelter currently cannot meet the
         EPA regulations due to the smelter's inherent emis-
         sion fluctuations.  The data available to the Agency
         support the conclusion that Kennecott cannot comply
         with the current emission lindfetion.  However, the
         data do not support Kennecott' s conclusion that
         its inability to comply is caused by the. fluctuating
         emissions at its smelter.  The preamble to the EPA
         regulations stated   :  "While EPA does not now
         have the information which would allow a determina-
         tion of the extent to which the equipment now in use
         at any affected smelter represents RACT  [reasonably
         available control technology] for that smelter, the
         information now available to the Agency  indicates that
         none of the seven smelters can meet  its  [ultimate]
         emission limitation,  at its maximum  production
         capacity, through the use of the equipment now
         on-line."   Indeed, the presence of major uncontrolled
         process gas streams,  such as the reverberatory  furnace
         at Kennecott,  results  in  large mass  emission rates
         and makes compliance with the ultimate emission limit
         extremely difficult  whence  smelter  is operating at
         its maximum production capacity.   Thus,  it  appears
         that a  smelter's  major gas  streams will  require
         emission control  in  order to permit  the  ultimate
         limit to be met and  standards  to be  achieved.
         However, if Kennecott 's  major  gas  streams were  all
         controlled  sufficiently,  then  the  smelter's ultimate
         emission  limit would be achieved.   Fluctuating
         emissions  do  not represent an insurmountable barrier
         to  the  installation of control  equipment,  and
         therefore  do  not constitute grounds for a claim
         of technological infeasibility by smelters.   The
         copper  smelting industry itself contains an excellent
         example of the capability ojC control equipment
         which  has  been installed i»Jfa*$f8pess with fluctuating
         emissions.   Sulfuric acid planOfiave been successfully
         used at most copper smelters to control converter
          gas emissions which fluctuate drastically.
1343 FR 758.
                               -64-

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         As additional control technology is installed at
         nonferrous smelters in the next few years, a major
         effect of this equipment will be the damping of
         fluctuations in emissions into the atmosphere (see
         Section VII.F.)-   For example, the emission fluctua-
         tions in uncontrolled process streams leaving a
         smelter today will be part of the gas stream charac-
         teristics entering an acid plant in the  future.  When
         measured in the output stream of thejcid plant tail-
         gas, these emission fluctuations will be considerably
         reduced.  This is  due t3the  "thermal inertia" of the
         acid plant catalyst bed which smooths out  fluctua-
         tions in gas stream concentrations   .  Furthermore,
         the fluctuations  in mass  emission rates  from this
         control equipment will be very low in magnitude
         when compared  to  current  mass rate fluctuations
         at an uncontrolled smelter.  This will reduce the
         effect of  fluctuations on achieving  compliance with
         the ultimate limit.

         The above  discussion  demonstrates that emission
         variability  is a  function of smelter configuration,
         specific processes,  and  control  equipment. Thus,
         the feasibility of achieving EPA's emission limit
          (although  not  relevant to the  setting of that limit)
         must be considered from the perspective  of the  final
         configuration  to  be  used in meeting  that limit,
         rather than  the present smelter  configuration.

         On page  6  of Appendix G,  Kennecott  recognizes that
         since  a  smelter cannot operate at one,  specific
         emission-level on a continuous basis,  an average
         level  ojjemissions somewhat less  than the ultimate
         emission  limit must be achieved to  insure that   §
          actual  emissions do not exceed the  maximum emission
          limit.   This condition is as true for anyistationary
          source  that experiences emission fluctuations  afpit
          is  for nonferrous smelters.  C9nsider,  for example,
          a power  plant whose typical emission variability
          characteristic is steadier than a smelter's (due
          to  its  relatively constant operating load versus a
          smelter's batch operation).  Since the power  plant's
          emission limit represents a maximum figure never
          to  be exceeded, the source operator designs his
          control  equipment and operates in such a  fashion



14Browder's work:piDCo cost estimate for Douglas  acid plant.
                   Bunker Hill work.
                               -65-

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that the worst case  emission variability is
accommodated.   Only  in this way,  can the operator
assure compliance  with the established emission
limit and  attain the standards.   Additionally,
such equipment design and operation can be
expected to  result in average emissions that are
less than  the  maximum emission limit.   Thus,  a
g^-n-^.r,  amigcion variability iff arcominodiit.i!.d?*
Only in tnis way,  can tne operator assure compliance}
with the established emission limit and attain  the_^s*
^standards-XflSfftieBally, auoh equipment deoign. ana
            an
       '••'•'"> g  •'""qt arr Irnn than thn mrmlTmiim
         Thug*  £. smelter's emission variability is
 a process condition,  typical of many stationary
 sources,  that can be  accommodated by proper control
 equipment design and  smelter operation so that the
 ultimate limit is achieved.
 A further analogy can be derived from a considera-
 tion of control equipment design.  For example,  if
 a 95% efficiency for an electrostatic precipitator
 is necessary to meet a continuous requirement,
 proper design o-f the ESP will exceed 95% efficiency
 to account for, anupng other things, commonly
 occurring variability in emissions expected from
 i.'L  TTC'D                                      •
 *, . fJucfuafrVj />/J?err;«* farJ/frrtnT ^nJ ^m'^^^L wAreJ ttW 6V e
 The ultimate result of this emission variability
 as Kennecott points out on page 6 of Appendix G,
 is that "...most of th|fime the smelter is emitting
 at much less than the allowable rate, and it is
 unlikely that the time of maximum emissions will
 coincide with the worst dispersion conditions."
 At this point, Kennecott !s ultimate recommendation
 is taking shape:  one should utilize the fluctuating
 characteristics inherent in atmospheric dispersion
 to determine an emission limit for a certain per-
 centage of time is that "...it is unlikely that the
 time of maximum emissions will coincide with the
 worst dispersion conditions" (pg. 6).

 However, Kennecott 's argument for considering the
 "unlikely," although possible, coincidence of
 maximum emissions and poor dispersion is in direct
 conflict with section 123 of the Clean Air Act.
                     -66-

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 Section 123 clearly states that intermittent con-
 trol of emissions varying with atmospheric cond-
 itions may not be considered under Section 110.
 Section 123(a)(2) states, "(t)he degree of emission
 limitation ... shall not be affected in any manner
 by any ... dispersion technique" (except good engi-
 neering practice stack heights).  Section 123(b)
 defines "dispersion technique" as "... any inter-
 mittent or supplemental control of air pollutants
 varying with atmospheric conditions."  The fact
 that Kennecott's proposed emission limit would not
 be directly correlated to atmospheric conditions,
 but is based on an assumption regarding atmospheric
 conditions, does not alter the conclusion that it
 is basically an intermittent or supplemental control
 system.

 Thus, Kennecott's recommendation would conflict
 with the mandate of Section 123./By permit-Ling
,'an ^Ifttssioh liMiL -tt-jwilli) lion b>0 of the time and
\ utilizing the dispersion effects of the atmosphere
1 to hopefully handle excessive emissions during
ithose times, Kennecott would be altering the required
.!degree of emission limitation by intermittently
1 controlling its emissions? 5% of the time Kennecott
jwould rely on atmospheric dispersion to diffuse  its
 luncontrolled emissions.  Such a concept is not
 |allowed__under Sectigns_JL10_and  123 of the Act._		/'

 Furthermore, «RAemission limit  with a 5% exemption
 conflicts with the definition of  "emission limita-
 tion" under the Clean Air Act.  Section 302(k)
 defines  "emission limitation" as  "... a requirement...
 which limits  the quantity, rate,  or concentration
 of  emissions  of  air pollutants  on a continuous
 basis  	"   Kennecott's recommendation, however,
 would  limit emissions continuosly for only  95%  of
 the time, permitting uncontrolled emission rates for
 5%  of  the time.  The 5%  exemption is  apparently
 unrelated to  valid malfunction  conditions wjiich could
 be  exempted as discussed in  Section IV.  Tbjs
 recommendation by Kennecott,  then,  would not
 represent an  emission  limitation  for  the purposes
 of  the  requirements  in  the  Clean  Air  Act.
                      -67-

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->
In Appendix G, Kennecott's theoretical approach to
calculating an emission limit relies on the same
basic concept utilized by EPA in the 1/4/78 promul-
gation:

     Let C = air quality concentration

         D = atmospheric dispersion factor

         E = smelter emissions.

     Then,

                                          a7*^ '*
                                     -
Thpi proportional  m9delj^as/c?iticized  extensively
by Kennecott in their Petition because  of  Kennecott's
contention that there is no direct relationship
between emissions  and air quality readings.
However,  this is in fact the baaic concept Kennecott
recommends in Appendix G.TTThWjnodel utilizes the
key parameters discussed previously:  air  quality
standards and concentrations (C), source emissions
 (E),  and dispersion (D).  In the use  of this
model,  EPA accounted f9r variable atmospheric
dispersion by considering a year's worth of air
quality monitoring and then assuming that  under  a
given set -of dispersion conditions (i.e.,  the
conditions which existed on the day of  the highest
 ambient air quality reading) that air quality is
 directly proportional to the emissions. Actual
 air quality readings and emissions are  then used
 to calculate an emission rate which will assure
 that the NAAQS will be attained under the  same set
 of dispersion conditions. <« Kennecott,  on the other
 hand,  calculates  a dispersion  factor through
 complex and sophisticated  theory  involving statistical
 methods .  Ttenneeott ' s model  also  assumes that air
 quality is directly  proportional  t;n the emissions
 under a q-ivftn  set of dispersion  conditions.
 However,  in contrast to EPA's  approach Kennecott's
 approach  useja  statistical distribution of dispersion
 conditions  (obtained from  a statistical distribution
 of air  quality readings) and a statistical distribu-
 tion of emssions  to  calculate  a  new emissions
 distribution which will  assure that^the NAAQS will
 be attained on a  statistical basis. X Kennecott has cxbo
 failed  to explain how its  5% emission  limitation
 exemption will ensure that the NAAQS are  attained
 on a statis%cal  basis.

                        all

-------
   loop
Kennecott's approach to deriving an ultimate emission
limit utilizes air quality data from the period
April 1976 to March 1977.  However, the representa-
tiveness of this data set is highly questionable for
two reasons relating to the use of dispersion tech-
niques under section 123.  First, these data were
collected after ASARCO began use of its 1000 foot
stack on July 1, 1974.  No demonstration has been
performed pursuant to section 123 which justifies
this stack height as "good engineering practice" for
ASARCO.  Thus, unauthorized credit for the stack
height may be influencing the air quality concentra-
tions used in Kennecott's Petition.  Second, emission
curtailment procedures under the joint Kennecott-
ASARCO SCS plan were periodically employes dispersion
techniques during this time period (April 1976 to
March 1977).  The 1976-1977 air  quality data were
thus affected by intermitteiCj£urt ailment procedures
at Kennecott and ASARCO  as well  as the increased
stack height at ASARCO.  Use  of  these two dispersion
techniques means that the data used in the Kennecott
Petition may not be  representative of air quality
data required to be  considered under section 123.
Therefore, these data should  not be used to derive
an emission limit.   The  1973-1974  data used by EPA
to calculate its emission  limiations were not influenced
       operation or  ASARCO 's  1000  foot stack.
           important consideration relating to  the  use
 of this data set revolves around Kennecott's assump-
 tion of independence between emissions (E) and
 dispersion (D).  Pages 6 and 12-13 of Appendix G
 utilize a concept of independence between D and E  to
 derive the dispersion function,  D.  However, if an
 emission data set which has been influenced by SCS
 curtailments is utilized, as in the case of the
 Kennecott Petition, then D and E are not independent.
 During operation of an SCS, emissions are varied in
 response to the dispersion conditions (weather and/or
 meteorology).  Thus, the data set Kennecott uses
 violates a major assumption made by Kennecott  during ir\
 its emission limitation calculations contained in
 Appendix G.  If such data were used in Kennecott^
 statistical model {contained in Appendix G of th^ex
 Petition), the resulting emission limit would not be
 stringent enough to ensure protection of the NAAQS
 for sulfur dioxide.

                Kc«««e.t+ »i«s  failed
       --- .-

  b«s«. is
                     -69-

-------
        On page  2  of the  Appendix G,  Kennecott  states that
        their  recommended approach "benefits  the  environ-
        ment."   However,  a comparison of their  recommended
        emission limit and the total  of the EPA limits
        for  the  two Hayden smelters shows that  Kennecott  s
        limit  would permit sulfur dioxide emissions  more
        than three times  greater than allowed under  the
        EPA  emission limit:

             Kennecott Limit          EPA Total Limit

              13,740 kg/hr             3890 kg/hr
              (30,300 Ib/hr)           (8560 Ib/hr)

         Furthermore, Kennecotts' limit also can be exceeded
         5% of the time, while the EPA limit must be
         achieved at all times.

         Since EPA's emission  limits would permit significantly
         less S00 emissions, Kennecott!s  approach is in fact
         detrimental to the environment when compared with
         the EPA approach.

         It is interesting to  note  that Kennecott partially
         bases its  argument of environmental benefit on the
         concept that  EPA's limit "allows the smelter to emit
         at the maximum emission limit all of the time
         (pq   10).   However, Kennecott has spent  the previous
         nine pageT*f Appendix G indicating  that this in
         fact  does  not happen  during  real operation.
               1 VST S  Of
          air  quality monitoring shows that theshorj>^erm
          Sir  quality standards (establishfi^-ttr^rotect public
          health and welfarejrejpiire-^ne^greatest emission^
          reductions and^ar^^he most difficult to achieve.
          Attajjiiag-'tneannual average standard, by contrast,


          EPA's ^preliminary analysis fo Appendix G indicates
          that the Kennecott statistical method has several
          problems associated with its use as a method for
          calculation of smelter emission limitations.  As
          discussed above, these problems are:


15EPA Technical Support Document, Arizona smelter regulations,
  November 1977.
                               -70-

-------
L
    The use of data influenced by operation of
    the ASARCO-Kennecott joint SCS violates the
    assumption that tl^emission rate is independent
    of dispersion conditions.  It may also allow
    improper credit for a dispersion technique in
    the determination of an emission limitation
    under sections 110(a)(2) and 123.  The use
    of such data might not insure attainment of
    the NAAQS.

    The use of data influenced by the use of ASARCO's
    new tallitack may  allow -|V improper credit for
    a stack height greater than good engineering
    practice  (a dispersion technique) in the deter-
    mination  of an emission  limitation under
    sections  110(a)(2)  and 123.

    The 5% exemption  from compliance with  the
    emission  limitation is not consistent  with the
    definition of  emission  limitation  in  section
    302(k) and may not ensure attainment  of the
    NAAQS.

    The  statistical method  proposed by Kennecott
    in Appendix  G is not explained in  sufficient
    detail to allow its use by EPA for calculation
    of smelter emission limitations.   Further, the
    reliability and representativeness of the air
    quality and emission data used were not
     addressed by Kennecott.

For these reasons,  EPA rejects Kennecott's request
to use its stastical method of emission limitation
calculation as proposed in Appendix G of its Petition.
However,  if the major problems with this method are
corrected, the statistical technique proposed by
Kennecott could be an  appropriate method for
calculation of smelter emission limitations. JTyc
LBowerman/BHaller
reading/file
6/6/79
6590
            C
                  urinttrx
                             Bi\\
                          -71-

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VIII. Monitoring Requirements:

     Three of the copper smelters (ASARCO, Inspiration and
     Phelps Dodge) questioned whether EPA had specified
     reasonable monitoring requirements with which to deter-
     mine compliance with the sulfur dioxide emission limita-
     tions.  There were three major areas which were questioned
     by the smelters:

     1.   The availability of continuous  instack  sulfur
          dioxide monitors for  smelter  gas  streams  (ICCC  and
          PD),

     2.   The  availability  and  accuracy of  continuous  instack
           flow  rate measurement devices for smelter gas
           streams  (PD),  and

      3.    The  reasonableness of the time allotted to conduct
           manual tests for sulfur dioxide using EPA test
           Method 8 (ASARCO and PD).

      EPA's responses to the specific issues raised by each
      smelter are discussed below.
                            '*             (DRAFT)

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A.   The Availability, Reliability and Accuracy of
     Continuous  Instack Sulfur Dioxide Monitors for
     Smelter Stacks  (ICCC  and PD);

     Both  Inspiration and  Phelps  Dodge questioned EPA's
     determination that continuous  ins tack sulfur
     dioxide monitors are  available for  all smelter
     stacks .
     I.
      On pages 2 and 3 of Exhibit A of its Petition
      Inspiration states:

           "Equipment is available to consistently and
           accurately monitor  acid plant tail gas stack
           emissions  (Dupont infra-red unit) but the
           technology  for  the  continuous measurement of
           S09  in hot,  dusty,  corrosive gases of high
              &
           dew-point is not available.  This was con-
            firmed during reading of paper at  annual
            symposium of Instrumentation Society of
            America in Salt Lake City in November,  1977."

       EPA disagrees with  Inspiration's claim that continu-
       ous instack sulfur  dioxide monitors are not available
       to monitor its emissions  for the following reasons:

                                      (DRAFT)

-------
All process gases at Inspiration are {nuJiLi'i
treated in a double absorption sulfuric acid
plant.  Inspiration has stated that it can
continuously monitor emissions from a sulfuric
acid plant and has not  indicated that the
problems  cited in its Petition apply to
monitoring of acid plant  emissions.

Some  process  gases  are  bypassed  around  the
acid  plant under certain  conditions.  Unlike
sulfuric  acid plant gases,  these gases  are
hot and dusty and they may have  a high  dew
point.  This is a result of the  fact that
                     b e*n frectf«a »/
these gases  have notfrundaifgeno the cooling
 and ^xLii'uiva particulate removal systems
which precede the processing of gases in a
 sulfuric acid plant.  EPA believes that a
 properly designed reliable monitoring system
 can be installed in the  bypass stack based on
 a survey  of manufacturers of continuous
 monitoring systems conducted by EPA in August,
 1976.  As discussed in the preamble to the
 EPA  regulations (43 FR 758, column 1,  January
 4, 1978)  responses to  the  survey  on the
 availability of continuous  sulfur dioxide
                           (DRAFT)

-------
,V\
° \
                  monitors at smelters indicated that such
                  monitors were currently available and that
                  the manufacturers would guarantee the operation,
                  reliability and accuracy of such monitors.
               ^fPeriods of acid plant bypass should occur
                ^!relatively infrequently if Inspiration
                  chooses to comply with its SIP emission
                 ;limitation.  Further^ the concentration and
                  mass of sulfur dioxide emitted from the
                  bypass stack will be large in comparison to
                  the emission limitation for ICCC.  Therefore,
                  the relative accuracy of bypass stack monitors
5,°( ^            doesn't have to be as good as it does for the
v'.r^1

-------
              If  monitors  are installed to measure collected
              fugitive emissions,  these gases will not be
              hot and corrosive,  or have a high dew point.
              If  they are dusty,  a baghouse or equivalent
              may be required upstream of the monitoring
              site.  In the absence of such a control
              device, a filter could be installed on the
              monitor sample line to remove particulate
              matter  from the sample and  protect  the continuous
              monitoring equipment.  In short,  continuous
              monitors  are  available to monitor collected
              fugitive  sulfur  dioxide  emissions.   At the
              present time  Inspiration does  not collect any
              of its fugitive emissions for  venting to the
                                 ow
              atmosphere through^stack.

          In summary, the sulfuric acid plant is the primary
          emission point at  Inspiration,  and the Company
     y 7  /"agrees that this point can be monitored.  The by-
A'«O-'  I Pass stack  is also of interest  to EPA,  even  though
          it should be  used  much  less  frequently  than  the
          acid plant  stack.  EPA  believes that reliable
          sulfur dioxide monitors are  available for the by-
          pass stack and  for the  collected fugitive gas
          streams at Inspiration for the  reasons  outlined

                            r.
                                          (DRAFT)

-------
above, and because of  instrument manufacturers
statements  (43 FR 758, column 1, January 4, 1978).
2.
On pages  7  and 8  of the  Supplemental Comment to
its  Petition Phelps Dodge states  that  it had
demonstrated "the infeasibility of measuring in-
stack SO2 emissions accurately on a continuous
basis."   Phelps Dodge claims that continuous
instack sulfur dioxide monitors are infeasible  and
inaccurate because of the following problems:
      Sulfur dioxide concentration in large smelter
      stacks is subject to stratification,

      A gas sample extracted from a smelter stack
      is subject to alteration which could affect
      the measurement  of  the sulfur dioxide con-
      centration,

      The instrument response  time maje  too long,
J10I    The instruments are unreliable,  and
                      6.
                                (DRAFT)

-------
     The instruments require excessive maintenance
(November 16, 1977 Interoffice Correspondence from
James E. Foard to M. P. Scanlon of Phelps Dodge).

EPA disagrees with Phelps Dodge specific conten-
tions as follows:
     Stratification of gaseous pollutants  in large
     circular  stacks would not be  expected because
     of  good mixing and flow conditions  in these
                       fesh f•*-.
     stacks.  However,^stratification can  be
                  and ^ if*4EH% handled in accordance
      with paragraph-4, Performance Specification
      2,  Appendix B, 40 CFR Part 60(which provides
      for the use of (diluent monitors or the use ofj
      multipoint sampling probes).
      Gas sample alteration can be^handlod with
      proper design and maintenance.  This problem
      does not make sulfur dioxide monitors in-
      feasible or  inaccurate.  Further, any such
      alteration in the  sample will  remove sulfur
      dioxide  from the gases  and  thus result in
      lower  than actual  sulfur dioxide  concentrations
                       7.
(DRAFT)

-------
(a situation which would benefit Phelps
Dodge).  Sample line temperature can be
maintained at gas temperature through line
heating and/or insulation.  Air leaks into
the system can be detected when the instrument
              
-------
52),  although shorter response times are
preferable.  The response times of 2-4 seconds
or 1 minute specified by Mr. Foard are acceptable
to EPA.

Phelps Dodge has presented no  information to
show that  sulfur dioxide concentration monitors
are unreliable.  Instrument manufacture's
willingness to  guarantee reliability  in
writing  is more persuasive  than Phelps Dodge's
unsubstantiated contentions regarding relia-
bility (43 FR 758,  column  1,  January  4,
1978).   Further, EPA has  required the instal-
lation of continuous sulfur dioxide monitors
 for  new copper smelters under NSPS (New
 Source Performance Standards) at 40 CFR
 60.165 and 60.166 and has determined that
 this is a reasonable requirement.  Finally
 EPA is requiring installation of continuous
 sulfur dioxide monitors for numerous other
 categories of new and existing stationary
 sources under  authority of Sections 110(a)(2)(F)
 and 111 of the Clean Air Act  [40 CFR 51.19(e)
 and Appendix P, and 40 CFR Part  60].
                Q
                           (DRAFT)

-------
Phelps Dodge has presented no evidence to
show that these systems require excessive
maintenance.  All instruments, processes or
control equipment require regular maintenance
for proper operation.  EPA believes that con-
tinuous monitors for sulfur dioxide concen-
tration do not require excessive maintenance.
Phelps Dodge admits that in-situ monitoring
systems have reasonable maintenance require-
ments, except when the gas stream temperature
is below the dew point.  When Phelps Dodge
installs control equipment sufficient to
comply with EPA's SIP emission  limits,  the
gas streams will contain much smaller amounts
of particulate matter  (including  sulfuric
acid).  Thus, the excessive maintenance
problems  (which Phelps Dodge  implies are
caused by  sulfuric  acid  and other particulate
matter) will  eventually  be greatly  reduced.
In the interim, the  continuous  monitoring
systems will  have  to be:
      conditioned for particulate (including
      sulfuric acid) removal prior to analysis
      for extractive monitoring systems, jMH
                /O.
(DRAFT)

-------
          maintained and cleaned on a regular
          basis for extractive and in- situ monitoring
          systems .
Phelps Dodge also claims that instrument representa-
tives consulted by EPA did not state "unequivocally
that his company has, right now, a system that
will function under the conditions encountered in
our stacks at acceptable levels of reliability and
accuracy and without requiring excessive maintenance."
It is true that their were no "unequivocal statements"
made by the various instrument manufacturers.
However, as discussed in the preamble to the
regulations, the manufacturers did indicate that:

     "they would build  and install such monitors
     under a turnkey contract and that they would
     guarantee the  operation, reliability, and
     accuracy of this equipment  including specifi-
     cations such  as equipment calibration and
     range sensitivity."   (43 FR 758, column  1,
     January 4,  1978)

In summary, the  willingness  of  instrument manu-
facturers to build monitoring  systems on a turnkey

                  //,           (DRAFT)

-------
basis and to guarantee reliability is adequate
evidence that the monitors are available.  It is
not necessary that manufacturers make these statements
unequivocally.

Since many  smelters  in Arizona and Nevada have
instack sulfur  dioxide monitors at the  outlets of
their sulfuric  acid  plants and in other process
gas streams, the availability of sulfur dioxide
                                        in«M5ft/M>l*-
monitors  for sulfuric acid plant tail  gases island
was not challenged by any smelter.   Phelps Dodge
even stated that sulfur  dioxide monitors are  used
at its smelters to measure  SQ^ concentrations in
all of its  stacks,  although  allegedly  inaccurately.
The procedures  specified in  Appendix D will require
regular maintenance  of the  instruments, but will
                                       x*^ (u
 result in accurate,  reliable results./ The following
 smelters already have continuous
 monitors^
                 -I uulfur dimnrjr nrn mbliainnti fry
                         und £Iu» mfee. flimul
 sulfuric acid plants:
                      •*» in gas streams other than
                                (DRAFT)

-------
    Kennecott,  McGill,  Nevada  - main  stack  ("dirty"
    reverberatory furnace and  converter gases) -
    Dupont 460  photometric S02 gas  analyzer (Page
    5  of Reference No.  1).

    Kennecott,  Hayden,  Arizona -  reverberatory
     furnace stack (relatively  "clean" in  terms of
    particulate matter).  Page 2  of Reference No.
     2.

     ASARCO, Hayden, Arizona  roaster/reverberatory
     furnace duct  (relatively "clean" in terms of
     particulate matter).  Reference No.  2.

     Magma, San Manuel, Arizona - reverberatory
     furnace stack ("dirty").
EPA reaffirms its conclusion that continuous
instack sulfur dioxide concentration monitors are
available, accurate and  reliable for copper smelter
gas streams.  See also Reference No. 3, especially
Sections 4.2 and 5.2.

The sulfur dioxide monitors discussed  above are
designed to measure only the concentration of

                    13,         (DRAFT)

-------
sulfur dioxide in the stack gases.  The mass
emission rate of sulfur dioxide is obtained by
multiplying the sulfur dioxide concentration by
the stack gas flow rate (with appropriate conversion
factors).  The measurement of stack gas flow rate
is discussed in the following section.
                               (DRAFT)

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B.   The Availability and Accuracy of Continuous Instack
     Volumetric Flow Rate Monitors for Smelter Stacks (PD):

     Phelps Dodge  questioned  the  reasonableness and
     validity  of the EPA regulations because of an
     alleged lack  of availability of instruments to
     continuously, and accurately monitor stack gas
     volumetric flow  rates in stacks such as those at
     its  three smelters.  Phelps Dodge claims  that con-
     tinuous volumetric flow rate measuring devices  are
     unavailable and inaccurate because of:

      1.   The impossibility of accurately measuring
                 •
           total stack gas flow rates from a single
           point in a large stack,

      2.   The presence  of turbulent flow in the stacks
           and the resultant  large velocity fluctuations,

      3.   The  low flow rates encountered in the stacks
           at  Phelps Dodge,  and

      4.   The presence of "dirty" (contaminated) smelter
           gases which could cause build-up of "particulate
           accretions" on the velocity measuring  devices
            and result in distorted readings.
                                     (DRAFT)

-------
(from pages 7-8 of Phelps Dodge's Supplemental
Comment to its Petition, and Interoffice Correspon-
dence from James E. Foard to M. P. Scanlon of
Phelps Dodge dated November 16, 1977).

EPA disagrees with Phelps Dodge's contentions that
volumetric flow rate measurement is infeasible and
inaccurate in stacks such as those operated by
Phelps Dodge.  Regarding the availability of con-
tinuous volumetric flow rate instruments, detailed
discussions of specific instruments and their
accuracy and availability can  be  found in References
No. 3  (especially  Section 5.1) and No. 4.

More specifically  several copper  smelters have
already installed  continuous volumetric  flow rate
monitors,  including  at least the  following:

1.   Kennecott,  McGill, Nevada -  main stack  (dirty
     reverberatory furnace  and converter  gases ) ;
     Ellison Annubar,  Model No. 860,  primary  flow
     element,  316  stainless steel construction
     with  Leeds  and Northrup Model  1913  flow
     transmitter (page 5  Reference  No.  1  and
     Reference No. 5) .
                               (DRAFT)

-------
2.   Kennecott, Hayden, Arizona - reverberatery
     furnace stack  (clean); Hastings Raydist Gas
     Flow Probe (Page 2 of Reference No. 2 and
     Reference No.  5).

3.   ASARCO, Hayden, Arizona - roaster/reverberatory
     furnace flue and converter flue  (clean to
     moderately dirty); Hastings Raydist Gas Flow
     Probe  (Page 2  of Reference No. 2 and Reference
     No. 5).
                                           *
4.   Kennecott, Salt Lake City, Utah  -  main stack
      (total smelter gases, most of  which  are pro-
     cessed in a  sulfuric acid plant  and  are
     clean); Ramapo Mark  V Flowmeter  (Reference
     No. 5).

The  two  EPA publications  referenced above found
the  Ellison Annubar and the  Ramapo  Mark VI Flowmeter
to be  acceptable  continuous  volumetric  flow  rate
monitors.   However, the Hastings  Raydist  Gas  Flow
Probe  was  found to be unacceptable  (Reference
No.  3,  pages 60-68; Reference No.  4,  pages 20-36).
Any  of the above  referenced documents are available
 for  inspection by the public upon request at EPA's
 Region IX Office in San Francisco,  California.
                               (DRAFT)

-------
EPA has the following responses to the specific
objections raised by Phelps Dodge in its Petition:

1.   Single Point Measurement of Total Stack Gas
     Flowrate:  The /erformance ^Specifications for
     continuously monitoring the volumetric flow
     rate  from stacks  are contained  in Appendix E
     of 40 CFR Part  52.   Any such device  installed
     by Phelps Dodge must meet  the requirements of
     Appendix E, whether single point or  multiple
     point sampling  is used (both of which are
     allowed under the regulations). Among the
     requirements  is a field test  for accuracy of
     the  system.   This field test  involves a
     detailed comparison of the continuous monitoring
      device with the Reference method for volumetric
      flow rate determination (Method 2 of Appendix
      A to 40 CFR Part 60), as well as other checks
      for zero drift and  calibration drift.  The
      comparison with Method 2 involves a series of
           i
      14 simultaneous determinations using the
      measurement system and the reference method
      during  a 168-hour  test period.  When compared
      to the  reference method,  the measurement
      system  must have  a relative accuracy difference
      of 10 percent  or less.
                                (DRAFT)
                   ' o •

-------
    At many  stacks  a  single measurement point for
    the  continuous  measurement  system can be
    found  which meets the  relative accuracy
    requirement.  However, at some stacks a
    single point might not be accurate enough.
    In these cases  a  multiple point  continuous
    volumetric flow rate measurement system would
    be required.   Such a system could involve
    simultaneous sampling  at  several points
     (i.e., a line averaging device  such  as the
    Ellison Annubar)  or it could involve an
     automatic traverse with a single point measuring
     device (i.e., a pitot  tube  or a Ramapo Mark
    VI  Flowmeter).

     There is nothing in Appendix E of  40 CFR Part
     52  which prohibits or discourages  single
     point continuous volumetric flow rate measure^ —
    ment.  However,  any device installed must meet
     the relative accuracy criteria,  and this can
     be  achieved more easily using multiple point
     monitoring.

2.   Turbulent Flow in Large Stacks and Resultant
     Velocity Fluctuations:

                  JO          (DRAFT)

-------
Phelps Dodge presented some data which it
alleges showj that velocity cannot be accurately
measured in its Morenci Reverberatery Stack.
However, there is no indication as to how
these tests were conducted.  There is insuffi-
cient information present to enable EPA to
determine whether or not these tests were
conducted properly.  Phelps Dodge seems to be
saying  that the  differences in these test
results are caused  by  the turbulence in the
stacks.  The  large  scale velocity fluctuations
which Phelps  Dodge  alleges  occur in its
stacks  are  indeed.undesirable  and can  result
in inaccurate velocity determinations.   Such
fluctuations  are caused by  large  flow  disturb-
ances  (such as bends,  expansions  or  contractions
in the  duct work)  which cause  large  scale
wakes  and eddies to develop in the  gas flow
patterns nears those disturbances.   These
wakes  and eddies gradually dissipate in long
 straight ducts after a flow disturbance.

 The Phelps Dodge smelter stacks are large
'(greater than 20 feet in diameter).   However,
 the turbulence  (wakes and eddies) at a properly
                           (DRAFT)

-------
 located sampling site (see Method 1 of Appendix
 A to 40 CFR Part 60) will be relatively low,
 since such a site is not located close to a
; flow disturbance.  Furthermore, large stacks
 will tend to have a  flatter velocity profile
 and are usually less turbulent than small
 stacks.  This  will increase the chances of  a
 single point sampling probe being  representa-
 tive of the average  velocity  in the stack
  (References Nos.  6 and  7).

  In a  strict engineering sense all  flow in
  ducts  at  copper smelters is  turbulent and
                *
  will  contain small scale velocity fluctuations
  even in long straight ducts.   However,  these
  fluctuations are small and do not introduce
  the large errors (about which Phelps  Dodge is
  complaining) caused by the large scale turbulent
  wakes and eddies.  These large scale disturbances
  are caused by flow disturbances such as
  bends, contractions or expansions.  On Page
  288 of Harry White's book entitled Industrial
  Electrostatic Precipitation,  (parts of which
  were submitted by Phelps Dodge as Exhibit VI
  of its Supplemental Comments) he  indicates
                            (DRAFT)

-------
     that flow rate measurement accuracies of
                            i   •  " ';  '
     can be obtained.  I »>  M\cU-

3.   Low Flow Rates
     Phelps Dodge  also  implies that the low veloci-
     ties in their stacks will contribute to
     excessive  errors in the volumetric flow rate
     determination.  However, Phelps Dodge has
     failed to  quantify the velocities in its
     stacks and any errors  which might be associated
     with measuring low velocities.  There is no
     comparison between the velocities which can
     be  measured with a pitot tube and water
     manometer, and the allegedly low velocities
     in  its  own stacks.  In conclusion,  Phelps
     Dodge  has  presented insufficient  evidence  to
     support its claims.

                   alternative pressure transducers
     with greater sensitivity can be used (such as
      the Validyne differential pressure transducer,
            No DP103, and Transducer Indicator.
      CD12JJA if a water manometer is found to be
      insufficient to accurately measure the stack


                ^2>t            (DRAFT)

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     gas  velocity (volumetric flow rate)j I  Such
     pressure transducers are also easier to
     integrate into a total continuous  monitoring
     system,  since they have an electrical  output
     rather than a visual output (such as  a manometer
     or magnehelic gauge).  EPA has used such a
     device during manual source testing at Phelps
     Dodge, Ajo, Arizona, and Kennecott, Hayden,
     Arizona, in 1976  (Reference 8 and 9).

4.   "Dirty"  (Contaminated)  Smelter Gases  and
     Build-Up of Particulate Accretions on Velocity
     Measuring  Devices:
                *
     Phelps  Dodge  contends  that the build-up of
     particulate accretions on velocity measuring
     devices will  cause distorted readings.  There
     is  no doubt that many of the gas  streams  at
     Phelps  Dodge smelters are "dirty" and that
     build-up of particulate accretions can occur
     on velocity measuring devices.   However,
     three procedures will minimize the adverse
      impact of these accretions on the accuracy of
      the velocity measurements.
                                (DRAFT)

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   r o
1. / periodic purging of the instrument will
     prevent pluggingj^f a velocity pressure
     sensing instrument is selected.

2 .   A program of regular maintenance and
     cleaning (in accordance to the vendor's
     recommended schedules ) will insure that
     any instrument is functioning properly
     and producing valid data.

3 .   The instrument is compared to the reference
     method (Method 2) only after a 168-hour
     conditioning period.  This allows the
 «
     build-up of parti culate accretions to
     reach a steady state prior to the compari-
     sons.  Thus any distortions in the
     instrument readings will be accounted
     for during the field test for relative
     accuracy.  The system will not be acceptable
     to EPA unless it can be shown to have a
     relative accuracy of ten percent or less
     when compared with the reference method.

In summary, at least two continuous volumetric
flow rate measuring devices are -available
                          (DRAFT)

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which can accurately monitor the  flow in

copper smelter stacks.  Phelps Dodge has

failed to present  convincing arguments or

data to indicate that  such  devices  are unavailable

and/or inaccurate.                 \<*9f   |Cy.p.
                                        *'     '
                          (DRAFT)

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C.   The Time Allotted to Conduct Manual Tests for
     Sulfur Dioxide Emissions from Smelter Stacks Using
     EPA Test Method 8 (ASARCO and PD):

     Both ASARCO and Phelps Dodge questioned the reason-
     ableness of the EPA regulations because of the
     allegedly  insufficient time allowed to conduct the
     manual EPA Method 8 compliance tests for sulfur
     dioxide.
     On pages  18  and  19  of  its  Petition ASARCO claims
     that the  collection of three  consecutive two hour
     samples within a six hour  period  is difficult, if
     not impossible,  because there is  no allowance for
     the time  required to move  the sampling probe from
     port to port,  change the sampling train, perform
     leak checks,  etc.   ASARCO  requested that the
     regulations  be changed to  allow sufficient time to
     perform these tasks during a  compliance test.

     EPA is fully aware  that it will take  more than six
     hours to  perform the three consecutive two hour
     Method 8  tests,  and would  accept  such test results
     as valid  under the  existing regulatory language.
     However,  in  order to clarify  the  intent of the
                                    (DRAFT)

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regulations and eliminate a potential issue from
any review which might occur in the 9th Circuit
Court of Appeals, EPA will change 40 CFR
52.125(d)(6)(ii)(c) to read:

     "Three independent sets of measurements of
     sulfur dioxide concentrations and stack gas
     volumetric flow rates shall be conducted
     during three 6-hour periods for each stack.
     Each 6-hour period will consist of three
     consecutive 2-hour periods.  The total elapsed
     time for  each 6 -hour test may be as long as
     12_ hours .  Measurements of emissions from all .
     stacks on the smelter premises need not be
     conducted simultaneously.  All tests must be
     completed within  a  72-hour period."

     The  added sentence  is underlined.
On pages  8  and 9 of the Supplement to  its Petition
Phelps  Dodge claims that the requirement to con-
duct  manual EPA Method 8 compliance tests for
sulfur  dioxide within 72 hours is unreasonable for
a smelter that has two stacks to be tested, such
as the  Phelps Dodge smelters at Douglas and Morenci

                  2-7,         (DRAFT)

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At such a smelter these compliance test requirements
would necessitate collection of 18 separate two-
hour samples within a 72-hour period (2 stacks x 3
6-hour samples x 3 2-hour segments).  Phelps Dodge
alleges that this is unreasonable because of:

1.   "stringent" sample collection requirements,

2.   "complex, bulky and  fragile" sampling equipment,

3.   simultaneous volumetric  flow rate measurements,
     and

4.   sampling  sites that  "are several hundred feet
     above  the ground  at  locations reachable only
     by ladders."

Phelps Dodge  implicitly  asked for more than  72
hours to  conduct such  tests at its Douglas and
Morenci smelters.
                 /
EPA  does  not  agree  that  these sampling requirements
are  unreasonable for  smelters with  two or more
stacks, and therefore  denies the Petition of
Phelps Dodge  on  this  point.  The sampling require-
                               (DRAFT)

-------
ments for smelters with more than one stack will
remain the same as those  for smelters with one
stack.  The 3 -day sample  collection time limit and
other sample collection requirements are stringent,
but not unreasonable.  In order to complete these
requirements,  Phelps Dodge would probably need to
use two sampling crews to conduct its tests.  If
two crews are  used then one crew could be assigned
to each stack  and each crew must complete one 6-
hour  test per  day for three days in  succession.
Each  six hour  test will consist of three 2-hour
samples and could last  as long as 12 hours.
However, more  than  one  6-hour test at each  stack
may be  conducted on a single day,  if desired.
These compliance test requirements  are necessary
to  insure  that representative and accurate  test
results are obtained and to minimize the effects
  VarteiMe   o-erwii'nQconitfionS
of Aprocess^chi f f» on the test results.   One six-
hour  test per day per stack can be accomplished
without undue difficulty if two sampling crews  are
used.  The sampling equipment is not unreasonably
 complex,  bulky, or fragile.  It has been in use at
 sources since the early  1970 's.  Phelps Dodge will
 be  required to have available several sampling
 trains and sets of glassware, in case of failure
                                (DRAFT)

-------
or breakage during a test.  The collection of
simultaneous volumetric flow rate measurements
during these Method 8 compliance tests does not
significantly increase the time necessary to
conduct such a test.

Finally,  sampling site  access  is not  a complaint
sufficient to  invalidate  an  EPA  testing  requirement.
Phelps Dodge  is  fully aware  that compliance  tests
must be  conducted at sampling sites that meet
                       • i
Method 1 criteria, andA constructed such  sites in
the middle 1970's at Douglas and Morenci.  The
 fact that Phelps Dodge built the sampling sites
 into its present facilities is a strong indication
 that they believed that the sites were reasonably
 accessible.  EPA  is aware of the height of these
 sites as well as  the access to them, and does not
 believe  that conducting  one 6-hour test per day at
 each of  these sampling sites  is unreasonable.  EPA
 is  therefore  denying Phelps Dodge  implied request
 for more than 72 hours to conduct  Method 8  compliance
 tests for sulfur dioxide at its Douglas  and Morenci
 smelters.
                   3O>          (DRAFT)

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-eferences

I.    "Description of the Supplemental Control System,  Kennecott
     Copper Corporation, Nevada Mines Division, McGill,  Nevada,
     89318," submitted  as part of Attachment No. 2 of the
     October 7, 1976 Nevada SIP Revision Submittal.

2.    "Comments of Kennecott Copper Corporation, Ray Mines
     Division, Before the EPA, Hayden, Arizona, December 11,
     1975," Exhibit I,  "Joint Control Center Operators Manual"
     (dated September 12, 1975).'

3.    E. F. Brooks  and R. L. Williams, "Flow and Gas Sampling
     Manual,"  a report  prepared  for  EPA, Office of Research
     and Development by TRW Systems  Group, EPA-600/2-76-203,
     July, 1976.

4.    E. F. Brooks,  E.G. Beder,  C.  A. Flegal, D. J. Luciani,
     and R. Williams,  "Continuous  Measurement  of  Total Gas
     Flow  Rate from Stationary Sources,"  a report prepared
     for EPA,  Office of Research and Development  by TRW
     Systems Group, EPA-605/2-75-020,  February, 1975.

5.    Letter dated January 18,  1979 from W.B.  Schmidt, Chief,
     Air Surveillance and Investigation Section,  EPA, Region  X,

                          3/.            (DRAFT)

-------
     to A. Dammkoehler, Air Pollution Control Officer,  Puget
     Sound Air Pollution Control Agency.

6.   Telephone Conversation Summary dated September 15, 1978
     between Jim Peeler of Entropy Environmentalist and Larry
     Bowerman of EPA,  Region  IX.

7.   Telephone Conversation Summary dated September 15, 1978
     between Roger  Shigehara  of EPA, OAQPS and Larry Bowerman
     of EPA, Region IX.

8    J. Steiner,  "Stack Test  Results at Phelps Dodge Corpora-
                                   It
     tion,  Ajo, Arizona,"  Volumes I^jand III,  NTIS  Accession
     Nos.  PB 273177/AS to  PB  273179/AS, report to  EPA,
     Region IX,  from Acurex Corporation/Aerotherm  Division,
     Mountain  View, California, March  1977.

9.   R.  Larkin and J. Signer, "Stack Tests  at Kennecott
     Copper Cor&«BftiH», Hayden, Arizona Smslter,f^ublication
     No.  EPA-«8S/9-77-002, report to EPA,  Region IX from
     Acurex Cd^orati on/Aero therm Division,  Mountain View,
      California,  May  1977.

 LBowerman/BHaller
                          3Z,           (DRAFT)

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