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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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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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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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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= (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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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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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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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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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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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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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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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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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 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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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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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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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.
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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.
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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-
-------
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
-------
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
-------
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
-------
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.
-------
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:
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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.
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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-
-------
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-
-------
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-
-------
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-
-------
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-
-------
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-
-------
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-
-------
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-
-------
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-
-------
i literal H. -T.vif Z " Theorefuol
dfmulttfVmf fco»»b«
"* 1000 roof f fork. These
amount"
+,iJjjt&&mx±HS fiKCO'* looo Toot *r«rK. T>\e.s
wv/ootJi "ftff\J f~o rcjiuc^ i*^^ ai*\oun"r *r C"d*\T""tf* ^^^
fo affai^ NAAQ£,y*t &* £P# 1'^il *"** «**
sfriVo^\-f fivarv -^-^eces^ar/ '£>./>**}*<+&*
TK^sH^X cxrvoly^1'^ casts, a sK**** ei'a^ct « ^J
claiwv fl\f^ ^*—^?>Z^ «ftt* lf*P*y TA«» G>rn r
(mm.**. ~T at KCC rer/r/tHj-
-------
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-
-------
"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-
-------
I
•* O O O
•->
o
o
(M
• «
o
0
- •
0
0
o
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0
pfj
,',
,VI
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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-
-------
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-
-------
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.
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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-
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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-
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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-
-------
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
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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.
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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.
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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.
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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-
-------
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-
-------
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-
-------
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-
-------
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-
-------
->
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-
-------
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)
-------
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)
-------
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.
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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.
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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:
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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
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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
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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.
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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
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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.
*' '
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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
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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-
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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
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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)
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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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