EP ^50/2
76-501-3
4502765013
GUIDELINE SERIES
OAQPS NO. 3.0-003
LEGAL INTERPRETATION AND GUIDELINE TO
IMPLEMENTATION OF RECENT COURT DECISIONS
ON THE SUBJECT OF STACK HEIGHT INCREASE
AS A MEANS OF MEETING FEDERAL AMBIENT
AIR QUALITY STANDARDS
US. ENVIRONMENTAL PROTECTION AGENCY
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina
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LEGAL INTERPRETATION AND GUIDELINE TO IMPLEMENTATION OF RECENT
COURT DECISIONS ON THE SUBJECT OF STACK HEIGHT INCREASE AS
A MEANS OF MEETING FEDERAL AMBIENT AIR QUALITY STANDARDS
Office of General Counsel,
EPA, Washington, D.C.
and
Standards Implementation Branch
Control Programs Development Division
Office of Air Quality Planning and Standards
EPA, Research Triangle Park, North Carolina 27711
January 6, 1976
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CONTENTS
I. Introduction 1-2
II. Judicial Decisions 2-5
III. Implementation of the Judicial Decisions 6
A. Overview 6
B. Sources in Existence Prior to January 31, 1972
(the latest date by which SIPs were to be
submitted to EPA) 7-8
C. New Sources, i.e., Sources Receiving Construc-
tion Permits after February 8, 1974 8-11
D. Determination of Best Available Control,,
Technology (BACT) 11-12
E. Rationale for Use of Reasonably Available
Control Technology (RACT) as a Temporary
Measure 12-13
F. Determination of Reasonably Available Control
Technology 14-16
G. Relationship to SCS 16-18
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LEGAL INTERPRETATION AND GUIDELINE TO IMPLEMENTATION OF RECENT
COURT DECISIONS ON THE SUBJECT OF STACK HEIGHT INCREASE AS A
MEANS OF MEETING FEDERAL AMBIENT AIR QUALITY STANDARDS
I. Introduction
Section 110(a)(2)(B) of the Clean Air Act requires that
emission limitations must be used in State implementation plans
although "other measures as necessary" may be used to supplement
emission limitations in order to attain the national standards.
This section directs the Administrator to approve a State
implementation plan if:
it includes emission limitations, schedules,
and timetables for compliance with such
limitations, and such other measures a.s may
be necessary to insure attainment and main-
tenance of such primary and secondary standard,
including but not limited to, land use and
transportation controls.
While at one time, the meaning of the above language may
have been subject to doubt, the decisions of the courts (as
discussed below) now make it unmistakably clear that, in
legislating §110(a)(2)(B), Congress intended that State plans
would have to rely on emission limitations to the extent
possible, and that strategies which merely redistributed
pollution, e.g., SCS and stack height increases, were to be
used only as a supplement to emission limitations. Specifically,
as construed by the courts, it is clear that Congress did
not intend increased stack height and SCS to be used as a
means of attaining national ambient air quality standards where
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constant emission reduction controls were available. Thus,
it is only when constant controls are not available that
"other measures as may be necessary" may be turned to in
order to insure the attainment and maintenance of the national
standards.
So that State environmental protection agencies and
polluters subject to State implementation plans (SIPs) may
conduct their activities with certainty, EPA deems it desirable
to publish an interpretative guideline setting forth (i) the
Agency's understanding of the Courts' decisions, and (ii) the
manner in which the Agency intends to implement the decisions.
In sum, the sections which follow indicate when, if ever,
techniques which merely redistribute or disperse pollution may
be used as a means of achieving Federal ambient air quality
standards.
II. Judicial Decisions
The first decision to interpret section 110(a)(2)(B) was
that of the Fifth Circuit Court of Appeals, on February 8', 1974,
In that case, NRDC et al. v. EPA (489 F.2d 390), one question
before the Court involved the use of tall stacks as a control
strategy technique in the State of Georgia. In addressing this
issue, the Court held that a tall stack strategy, i.e., one
which establishes emission control requirements as a function
of stack height, or otherwise permits dispersion of pollutants
through increased stack height as a means of attaining or
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maintaining ambient air quality standards, could only be
employed under two circumstances: (1) where the constant
emission control requirements of the control strategy
are, of themselves, sufficient to attain the standards; or
(2) where the constant control requirements of the control
strategy (as expressed in either emission limitations or fuel
specifications) reflect the "maximum degree of emission limita-
tion achievable" and that, notwithstanding such requirements,
other measures -- such as 1SCS or tall stacks -- are necessary
if the national standards are to be attained.
The decision of the Fifth Circuit was recently followed
by the Sixth Circuit in Big Rivers et al. v. EPA, 523 F.2d 16,
(CA6, 1975) , and by the Ninth Circuit in Kennecott Copper
Corp. v. EPA, decided on November 28, 1975. In the latter case,
EPA invoked the teaching of the Fifth Circuit and argued that the
use of SCS as a permanent means of meeting ambient air quality
standards was impermissible under the Clear Air Act. However,
in making this argument, the Agency acknowledged that, in
some instances, there might be situations in which the installa-
tion of best available control technology (hereinafter BACT)
would be economically unreasonable or ill-advised for
engineering or siting reasons. Under such circumstances, it
was asserted that a fair interpretation of §110(a)(2)(B)
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would permit the following regulatory scheme: First, the
source in question would be required to install reasonably
available (as opposed to "best available" or "maximum
achievable") constant controls. Second, if the installation
of reasonably available control technology (hereinafter RACT)
was insufficient to achieve ambient air quality standards,
tall stacks and/or SCS would be permissible as an interim
means of achieving the standards. Finally, the source in
question would be required to conduct research for the purpose
of developing (and, ultimately, installing) new forms of constant
control techniques sufficient to achieve ambient standards at
a cost more reasonable than that of presently available BACT.
The regulation that was the subject of the ,Ninth Circuit
litigation followed the pattern described above. In upholding
the regulation, the Court indicated its agreement with the
result reached by the Fifth Circuit in the NRDC case and with
the Fifth Circuit's analysis of the pertinent legislative
history. The Ninth Circuit also stated that, similar to the
conclusion reached by the Sixth Circuit in the Big Rivers
case, it (the Ninth Circuit) believed that a recent decision
of the United States Supreme Court involving section 110 of
the Clean Air Act (Train v. NRDC et al, 421 U.S. 60, 7 ERC
1735 (1975)) added "significant support" to "EPA's interpre-
tation of 1857c-5(a) (2) (B) [i.e., §110 (a) (2) (B)] as expressing
a preference for emission limitations." (Kennecott Copper
Corporation v. EPA, Slip opinion at page 6).
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Although the Train case did not specifically address the
dispersion technology vs. constant control technology question,
the court did provide substantial insight into this question
in its overall discussion of §110. Describing what an
acceptable implementation plan must consist of, the Court,
at one point in the decision, drew a distinction between
ambient standards the achievement of which is the goal of all
implementation plans, and emission limitations, "the rule to
which operators of pollution sources are subject, and which,
if enforced should result in ambient air which meets national
standards." (7 ERG at 1741). Significantly, in making this
distinction the Court defined emission limitations as "regulations
[governing] the composition of substances emitted into the ambient
air from such sources as power plants, service stations and the
like." (7 ERG at 1741). The clear meaning to be drawn from the
above definition is that techniques which depend upon meteoro-
logical dispersion, such as SCS and increased stack height, do
• not control the composition of substances emitted into the air
and consequently cannot be regarded as "emission limitations"
for purposes of section 110 of the Clean Air Act. This was,
in fact, the meaning which the Sixth Circuit (in Big Rivers)
and the Ninth Circuit (in Kennecott) ascribed to the Supreme
Court's discussion of emission limitations.
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III. Implementation of the Judicial Decisions
A. Overview
The guideline which follows reflects EPA's understanding
of the Court decisions discussed in section II of this notice,
as well as the manner in which the decisions will be implemented
by the Agency. The elements of the guideline will be applied
to every State implementation plan. The guideline discusses
when stack height increases, including stack height increases
used in conjunction with supplementary control systems (SCS),
will be accepted by EPA as a means of meeting ambient -air quality
standards.
The general philosophy expressed in the guideline is that,
.«r
consistent with the decisions of the courts, stack height
increases and/or SCS are acceptable control strategy measures
only after the application of available control measures and
are never permitted as a means of allowing the increase of
emissions at any source.
Finally, although none of the decisions specifically
addressed the question of how the Clean Air Act's preference
for constant controls would be applied to new sources (for
purposes of (i) State new source review, and (ii) control
strategy demonstrations associated with later SIP revisions),
the guideline does specifically address this question in a
manner which EPA believes is consistent with the decisions of
the Courts.
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B. Sources in Existence Prior to January 31, 1972
(the latest date by which SIPs were to be submitted
to EPA)
Scope: This section addresses the manner in which stack
height will be considered with respect to sources in existence
on January 31, 1972. In other words, it applies only to sources
which are considered (either explicitly or implicitly) in
current SIP control strategies; it does not necessarily apply
to sources being subjected to new source review.
The section sets forth not only the basis for- approval
of SIPs, but also provides guidance with respect to revisions
of SIPs.
Implementation: In determining the control required of
an existing source for attainment and maintenance of the national
standards, a State may not take into account the dispersive
effects of an increased stack height for which construction
commenced after January 31, 1972 except in the following
circumstances:
1) If the source initiated construction
of the stack height•increase by grading and
pouring of concrete prior to February 8, 1974,
(the date of the Fifth Circuit Court's decision
regarding the use of increased stack heights),
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with the approval of the State (or authorized
governmental subdivision), permanent credit
in the SIP control strategy demonstration may
be taken for any increase up to 2 1/2 times the
height of the facility serviced by the stack.
(2) If the source applies best available control
technology {BACT), an unlimited stack height
increase may be credited in a control strategy
demonstration for attaining and maintaining
ambient air quality standards.
(3) If the source cannot apply BACT, but
applies reasonably available control technology
(RACT), an unlimited sback height increase may
be credited in a control strategy demonstration
as a temporary measure for attaining and main-
taining ambient air quality standards.
C. New Sources, i.e., Sources Receiving Construction
Permits After February 8,L 1974.
Scope: This section addresses the manner in which
stack height is considered for sources which received
construction permits after February 8, 1974, the date of the
Fifth Circuit's decision in NRDC et al v. EPA. As such, it
applies to sources which have already been or will be subjected
to new source review, and also applies to future control strategy
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demonstrations which consider those sources. The general
philosophy of the guideline is that, with the arrival of the
Fifth Circuit NRDC decision on February 8, 1974, both persons
seeking to build new sources and State new source review
boards were on notice that any attempt to meet new source
review requirements through the use of tall stacks might
well conflict with §§110 (a) (2) (B) and (D) of the Clean Air Act.1
Accordingly, while the guideline which follows does not attempt
to overturn or vitiate already-issued, post-NRDC v. EPA
construction permits that were predicated upen tall stacks,
the guideline does limit the amount of stack height credit that
may be assigned to such sources for purposes of later control
strategy demonstrations.
By contrast, construction permits issued after the release
of this guideline may not be based upon stack height except as
indicated below. Nor, except as indicated below, may stack
height credit be assigned to such sources for purposes of
later control strategy demonstrations.
I
Such knowledge can not be imputed to sources not part of
the original SIP control strategy and receiving construction
permits prior to February 8, 1974. Accordingly, such sources
(for all purposes) will be credited with whatever stack height
was committed to at the time of State new source review.
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Implement at ion:
1. Sources Receiving Construction Permits after
February 8, 1974, (the date of the Fifth Circuit decision)
and prior to the release of this guideline.
For purposes of EPA evaluation of state-issued construction
and/or operating permits, the source will be credited with what-
ever stack height it committed to at the time it submitted its
construction permit application (as approved) to the State.
For purposes of EPA review of control strategy demonstra-
tions accompanying later Plan revisions:
(1) If the source applied the best available
control technology (BACT), there is no restriction
on stack height. BACT is as defined in Paragraph
III(D) of this guideline.
(2) If the source did not apply BACT, it may
be given credit only for a stack height which
does not exceed two and one-half times the
height of the facility it serves.
(3) If the source cannot apply BACT, but applies
reasonably available control technology (RACT),
an unlimited stack height increase may be credited
in a control strategy demonstration as a temporary
measure for attaining and maintaining air quality
standards.
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2. Sources Receiving Construction Permits after the
release of this notice.
For purposes of (i) EPA evaluation of State-issued
construction and/or operating permits, as well as (ii) EPA
review of control strategy demonstrations accompanying later
Plan revisions:
(1) If a source applies the best available
control technology (BACT), there is no re-
striction on stack height. BACT is as defined
in paragraph III(D) of this guideline.
(2) If a source does not apply BACT, it may
be given credit only for a stack height which
does not exceed two and one-half times the
height of the facility it serves.
D. Determination of Best Available Control Technology (BACT)
For purposes of this guideline, BACT is as defined in
40 CFR 52.01. For source categories subject to New Source
Performance Standards (NSPS) as set forth in 40 CFR Part 60,
BACT is generally defined to be the same as NSPS. For those
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sources not subject to NSPS, BACT must be determined on a
case-by-case basis and the following must be taken into
consideration:
(1) The process, fuels, and raw materials
available and to be employed in the facility
involved,
(2) The engineering aspects of the application
of various types of control techniques which
have been adequately demonstrated,
(3) Process and fuel changes,
(4) The respective costs of the application
of all such control techniques, process changes,
alternative fuels, etc.,
(5) Any applicable State and local emission
limitations, and
(6) Locational and siting considerations.
E. Rationale for Use of Reasonably Available Control
Technology (RACT) as a Temporary Measure
In given instances, the technology envisioned by the
BACT concept may be available in a state-of-the-art sense;
however, its retrofit onto a specific existing source may be
extremely onerous for economic reasons or ill-advised for
engineering or siting reasons. It is expected that such
instances will occur only in the case of a few smelters and
some power plants. Nevertheless, where they do occur,
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particularly where a source is threatened with shutdown, the
Agency believes that administrative relief is appropriate.
Furthermore, it is the view of the Agency that, if handled
responsibly and if restricted to only the most compelling
circumstances, a willingness to deal fairly with in-being,
unavoidable problems, tends to strengthen, rather than weaken,
legal principles such as those expressed by the cases cited
above. This is especially true where, as here, the long term
goal of the relief measures employed is geared to realization
of the principles laid down by the cases.
Accordingly, where a source demonstrates to the State
(and the State thereafter demonstrates to EPA) that, as applied
to the source, BACT is economically unreasonable or technologically
unsound, EPA will approve a control strategy demonstration which,
for that source, is based upon reasonably available (as opposed
to best available) control technology coupled with unlimited
stack height. However, such a control strategy will only be
approved as a temporary measure for attaining and maintaining
ambient air quality standards and, where appropriate, will be
conditioned on the source undertaking a research program to
develop new and more economical forms of BACT-caliber technology.
As noted in section II, this approach was specifically approved
by the Ninth Circuit in Kenecott Copper Corporation v. EPA.
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F. Determination of Reasonably Available Control
Technology
For the purposes of this guideline, RACT is not necessarily
equivalent to the 40 CFR 51, Appendix B definition. RACT becomes
a factor only after it has been determined, on a case-by-case
basis, that retrofit of BACT on the existing source would be
unreasonable. This requires that RACT be determined by
considering the processes, fuels, and raw materials to be
employed; the engineering aspects of the application of various
types of cojitrol techniques, process and fuel changes; the cost
of employing the available techniques; and the cost of 'certain
control techniques due to plant location, configuration, basic
process design and expected remaining life. It is expected that
only some smelters and a limited number of coal fired power plants
will be able to justify application of RACT in lieu of BACT.
A review of costs of installing flue gas desulfurization
(FGD) at existing coal-fired power plants revealed that the
remaining life and capacity are major factors determining the
reasonableness of an FGD installation. For existing power
plants, the following should be considered in determining
reasonableness:
(1) If a plant has ten to fifteen years
remaining life or less, and is projected to
operate* an annual average of no more than 25%
capacity, FGD installation might be considered
unreasonable.
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In such instances, the source owner should provide
the anticipated shutdown date, and that date
must be included in the compliance schedule.
(2) FGD may be unreasonable due to space
limitations.
In the event that it is determined on a case-by-case basis
that FGD is not reasonable for a specific power plant, alternate
control measures must still be considered. The use of low
sulfur coal and coal washing, either separately or in
combination, might be appropriate options and acceptable in
meeting RACT criteria. The capital as well as operating costs
of applying these control techniques are to be taken into account
in making the case-by-case determination and, when the cost of
using low sulfur coal is not significantly less than the cost
of FGD, coal washing alone might be considered RACT. Only
after application of whatever measures are determined to be RACT,
would the source be able to take any credit for stack height
increase.
In the case of existing smelters, BACT will, in most cases,
be economically unreasonable and could, in some cases, result
in shutdown. Under such circumstances, RACT will usually equate
to control of all strong gas streams though properly operated and
maintained double contact acid plants (or single contact acid
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plants where single contact acid plants are already on line).
Where increased acid plant capacity is required to treat
presently untreated strong gas streams, RACT for such gas
streams must be double contact acid plants.
Since RACT involves a decision that is based principally
upon economic and engineering considerations, the definition
of RACT should be subject to future re-evaluation to determine
if more effective control measures would be applicable due to
technological advancements or changes in economic conditions.
Where the use of RACT has been approved by the State ^and EPA) ,
credit for stack height increases associated with .RACT would
only be permitted as a temporary measure.
G. Relationshipjbo SCS
As recognized by all three circuit court decisions
discussed above, supplementary control systems, like tall stacks,
utilize the dispersive characteristics of the atmosphere to reduce
ground level pollutant concentrations. Moreover, since the use
of SCS as a means of meeting ambient standards was the specific
issue addressed by two of the courts (the Sixth Circuit in
Big Rivers and the Ninth Circuit in Kennecott), the Agency deems
it important to include in this notice a guideline specifying
when, and the degree to which, SCS may be used as a means of
meeting federal ambient standards.
Because of the difficulties associated with enforcement
of an SCS program, before granting a source the right to use
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SCS, the source must agree td assume liability for violations
of the national standards in the vicinity of the source.
Consequently, SCS will be generally effective only for isolated
sources. Moreover, while the implementation of SCS is different
from conventional control measures or the use of taller stacks
after the application of RACT, it is clear that a stack height
increase can be a desirable addition to an approved, temporary
SCS especially where the frequency of curtailments could be
decreased by use of a taller stack.
There are generally three situations—limited to SO-
emissions—which permit the application of SCS:
(1) Oil to coal conversions ordered by FEA under the
Energy Supply and Environmental Coordination Act - Power
plants required to convert to coal are given up to 1979 to
install control equipment and/or use fuel which would comply
with the SIP. In the interim, ESECA requires that the primary
standards be met and an enforceable and reliable SCS can be
used to achieve that purpose.
(2) Enforcement Orders - When EPA issues an enforcement
order to a source to come into compliance with the SIP, it may
be necessary to require the source to apply an SCS for the
interim period in order to protect the ambient standards. There
would be no precondition that RACT be applied. However, in this
case, the source is not relieved from liability under section
304 of the Act, (i.e., would gain no immunity from citizen
suit), even if there are no violations of the national standards
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(3) SIP Revision -- Under this mechanism, a source can
not operate an approved SCS unless a number of conditions are met
2
including installation of RACT.
The stack height provisions in this guideline closely
parallel the circumstances in which SCS may be permissible
as an SIP revision. Both require, as a minimum, the application
of RACT and neither can be used to allow emission increases at
a source (except where oil to coal conversion is ordered under
ESECA). Each has distinct advantages which would make one or
the other, or some combination, the preferred measure in
specific situations. The main advantage of -employing^ SCS is
that this system forces the source owner to assume- liability
for any ambient standard violations in a given area surrounding
the source. However, for the legal reasons stated above, SCS
would always be a temporary solution for existing sources and
will not be allowed for new sources.
The restrictions on stack height apply solely to the
credit which can be given in assessing the impact of a source
on ambient standards. So long as stack height is not
used in lieu of emission reduction, the Agency encourages tall
stacks as a means of further minimizing the effects of
emissions on ground level concentrations.
2
An example of the conditions to be met may be found in the
regulations promulgated for a smelter in Nevada (the smelter
that was the subject of the Ninth Circuit's decision in the
Kennecott case). See 40 PR 5508, February 6, 1975.
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