-------
B.4.2 Example: Emissions Unit Applicability
In the second step, emissions unit applicability, the applicant
defines the refinery facilities that must apply BACT. The emission
units that do meet the criteria (Section 8.2.2) and, therefore, must
apply BACT are the four combustion sources associated with the proposed
modificationa fluid catalytic cracking unit regenerator, two heaters,
and a boiler. Although its emissions are accumulated for review, the
amine regenerator heater is not subject to the BACT analysis because it
was not subject to PSD review and was subsequently built under authority
of the State permitting system.
The applicant then presents relevant data on these emission sources.
As Table B-3 shows, the FCCU regenerator produces the most emissions;
therefore, this subsection focuses primarily on the BACT analysis of
this unit. The amine regenerator is not subject to the BACT analysis in
this case for two reasons: (1) it is not directly related to the FCCU
modification^, and (2) it was previously permitted and constructed.
However^.before considering the FCCU regenerator, the applicant
summarizes the BACT analysis of the boiler and the two heaters. The use
of alternative controls for NO and CO emissions, such as flue gas
treatment or another innovative technology, has been demonstrated by the
applicant to be economically unfeasible in light of the relatively small
amount of NO and CO emitted. Instead, proposed BACT consists of the
^
control techniques outlined below. The applicant proposes that the
heater and boilers burn a low-sulfur oil (0.15 percent sulfur by weight)
that also has a low-nitrogen content. In addition to sophisticated
firebox design and combustion controls, NO and CO emissions will be
further minimized by installing low-NO burners.
I-B-17
-------
Table B-3. FACILITIES SUBJECT TO BACT
Proposed emissions, Ib/hr
Facility
FCCU
Heater
Heater
Boiler
S02
1,165
8
14
24
N0x
274
8
14
24
PM
50
2
3.5
6
CO
203
2
3.5
6
HC
2
<1
<1
<1
I-B-18
-------
B.4.3 Example: Identification of Potentially Significant Concerns
In analyzing the FCCU regenerator, the applicant has identified
potentially significant impacts, as the BACT analytic process suggests.
The supply of skilled labor in the area, found by the applicant to be
adequate, would not be potentially affected by any of the proposed
control strategies. Energy was also found to be in adequate supply.
Coal shipments were, however, found to be somewhat limited; no coal
terminals could be located within a 100-mile radius of the source.
The applicant has determined that the limited availability of water
could cause a potentially significant impact. The low annual rainfall,
the unavailability of auxiliary sources of water, and the fact that
farming is the primary commercial activity in the area has necessitated
the rationing of water in this area on a priority basis. During a
drought, municipal water policy requires that residential and irrigation
areas be given priority over industrial needs. This factor may affect
the feasibility of a control alternative requiring large amounts of
water.
B.4.4 Example: Selection of Alternative Control Strategies
Based on the BACT analysis up this point, the applicant proposes
the following alternative control strategies, also shown in Table B-4:
1. For PM emissions, the alternative control strategies are a
high-efficiency electrostatic precipitator (ESP) with an
efficiency of 99 percent, a low-efficiency ESP with an effi-
ciency of 95 percent, a venturi scrubber with an efficiency of
90 percent, and tertiary cyclones with efficiencies of 85 percent.
I-B-19
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Table B-4. ALTERNATIVE CONTROLS FOR FCCU
Alternative control strategies Percent reduction
Alternative PM Controls
High-efficiency ESP 99
Low-efficiency ESP 95
Venturi scrubber 90
Tertiary cyclones 85
Alternative CO Controls
CO boiler 99.99
High-temperature regenerator 99
Alternative NO Controls
Flue gas treatment ?
No control 0
I-B-20
-------
2. For CO emissions, the alternative control strategies are a CO
boiler with an efficiency of 99.99 percent and a high-temperature
regenerator with an efficiency of 99 percent.
3. For NO emissions, the alternative control strategy is flue
gas treatment.
The applicant obtained the information on alternative control
strategies from petroleum refinery literature surveys and from the BID
for the petroleum refinery NSPS.
An alternative control strategy, to be considered as BACT, cannot
produce emissions in excess of any applicable NSPS or the allowable
emission levels of an applicable SIP. For example, new source perfor-
mance standards (40 CFR 60.100) limit PM emissions to 1 pound of PM to
1,000 pounds of coke burnoff and limit CO emissions to 500 parts per
million in the regeneration gases. These emission levels are also
required by the applicable SIP. Table 6-5 gives the anticipated residual
PM emissions of each alternative compared to the emission level required
by the applicable NSPS. Because the tertiary cyclone cannot meet this
level of PM emission reduction, it cannot be proposed as BACT. Since
both CO alternative control strategies can attain the emission rate
required by the NSPS, each is to be evaluated as a possible BACT.
Flue gas treatment has not yet been demonstrated to be a viable
control technique for NO emissions and cannot be properly evaluated for
BACT. Without demonstrated performance and adequate data for evaluation,
flue gas treatment for NO emission control could be considered innovative
^
at this time. However, the applicant has chosen instead to propose "no
control" as BACT for NO emissions.
I-B-21
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Table B-5. ESTIMATED PM EMISSION RATES
PM control alternative PM (lb)/1000 Ib coke burned
High-efficiency ESP 0.1
Low-efficiency ESP 0.5
Venturi scrubber 0.98
NSPS 1.0
Tertiary cyclones 1.5
I-B-22
-------
The applicant must next determine which combination of alternative
control strategies best controls PM and CO emissions. Table B-6 shows
the control strategy options ranked in descending order of control.
Because Option 6, the pairing of the venturi scrubber with high-
temperature regeneration, is the alternative control strategy that
produces the lowest degree of control and still meets the PM and CO
emission levels required by NSPS, this combination is chosen as the base
case.
B.4.5 Example: Impact Analyses
In evaluating the various control strategy options, the applicant
should remember that, because PM and CO emissions are controlled through
independent methods, control strategies for these pollutants should be
evaluated separately. The applicant has chosen to evaluate the PM
strategy first. Table B-7 gives the estimates of the installed and
annualized costs of each of the three alternative PM control systems
being considered. The cost estimates were based on vendor quotes, a
projected equipment life of 16 years, and a capital lending rate of
10 percent. The Chemical Engineering Equipment Buyers' Guide was used
for establishing the costs of each alternative.
The incremental, or differential, costs of each alternative control
strategy were calculated and then used to determine the cost of residual
PM emission control. The high-efficiency ESP is expected to cost about
$200,000 more than the low-efficiency ESP, which, in turn, is expected
to cost about $500,000 more than the scrubber.
The total and incremental PM emission reductions expected with each
alternative control strategy are given in Table B-8. The low-efficiency
I-B-23
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Table B-6. COMBINATIONS OF ALTERNATIVE CONTROL STRATEGIES
FOR PM AND CO EMISSIONS FROM FCCU REGENERATOR
1. High-Efficiency ESP - CO Boiler
2. High-Efficiency ESP - High-Teraperature Regeneration
3. Low-Efficiency ESP - CO Boiler
4. Low-Efficiency ESP - High-Temperature Regeneration
5. Venturi Scrubber - CO Boiler
" High-Temperature Regeneration
I-B-24
-------
Table B-7. PM CONTROL ALTERNATIVES' INSTALLED AND ANNUALI2ED
CAPITAL COSTS
($l,OOOs)
Alternative
High-efficiency ESP
Low-efficiency ESP.
Scrubber (base case)
Installed
Total Incremental
$1,700 " $200
1,500 500
1,000
Annuali zed
Total
$212.5
187.5
125
Incremental
$25
62.5
I-B-25
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Table B-8. TOTAL AND INCREMENTAL PM EMISSIONS CONTROLLED
Alternative control strategy
PM emissions controlled, tons/yr
Total Incremental
High-efficiency ESP
Low-efficiency ESP
Scrubber
4,.160
3,990
3,780
170
210
I-B-26
-------
ESP will control 210 more tons of emissions per year than the scrubber.
The high-efficiency ESP will reduce PM emissions by 170 tons per year
more than the low-efficiency ESP. Such emission reduction is known as
incremental emission reduction. The venturi scrubber provides an environ-
mental benefit by reducing S02 emissions from the FCCU by approximately
50 percent. Although, as discussed previously, S02 emissions are not
subject to PSD review, this favorable impact may be a factor in the BACT
decisionmaking. However, sludge disposal, an unfavorable environmental
impact associated with venturi scrubbers, would also be considered.
The energy consumption of each alternative control strategy is
given in Table B-9. Only direct energy consumption is considered. Fuel
used for indirect purposes, such as associated energy costs of
manufacturing the process materials, is not considered. For consistency,
energy consumption is evaluated on a total and an incremental use basis.
Energy consumption is also considered in calculating the operating costs
for the economic impacts analysis.
Table B-10 gives the annual operating costs of each PM alternative
control strategy during the first year of operation. These operating
costs represent the most significant costs of operating the alternative
control strategies and include utility, maintenance, process material,
and other variable costs. The major utility cost for each control
strategy is electricity. Maintenance material costs are assumed to be
1 percent of installed capital costs. Process material costs consist of
the cost of ammonia for the ESP and the cost of water treatment chemicals
for the scrubber. The most significant of the "other" variable costs is
the cost of sludge disposal for the venturi scrubber. Inflation of
I-B-27
-------
Table B-9. DIRECT TOTAL AND INCREMENTAL ENERGY
CONSUMPTION
(million Btu/yr)
Alternative
Direct energy consumption
Total
Incremental
High-efficiency ESP
Low-efficiency ESP
Scrubber (base case)
3.5 x 1011
2.0 x 1011
1..1 x ID9
1.5 x 1011
1.99 x 1011
I-B-28
-------
Table B-10. OPERATING COSTS OF PM CONTROLS
($l,000/yr - 1st year operation)
Scrubber Low-efficiency ESP High-efficiency ESP
Utilities $ 24.2
Maintenance 25.0
Process materials 137.0
Other 80.0
TOTAL , $266.2
$ 73.0
25.0
16.8
17.0
$131.8
$106.8
35.0
28.5
18.0
$188.3
I-B-29
-------
these operating costs is assumed to be 10 percent per year for the
5-year period following the startup of each alternative control strategy.
Table B-ll shows the 5-year operating costs of each strategy adjusted
for inflation. Again, for consistency, these costs are evaluated on
both a total and an incremental basis. Note that the operating cost of
the low-efficiency ESP is about $155,000 less per year than that of the
scrubber.
Combining the annualized capital costs and average operating costs,
as shown in Table B-12, gives the incremental and total annual costs of
each alternative control strategy. Again, note that the total annual
cost of the low-efficiency ESP is lower than that of the scrubber by
about $100,000 per year.
The applicant then determines the cost-effectiveness of each control
strategy by dividing the total annual costs of each strategy by the
amount of emissions controlled by each strategy. Similarly, incremental
cost-effectiveness is determined by dividing the incremental annual
costs by the incremental emission reductions. The incremental cost-
effectiveness value is a measure of controlling residual emissions of
one control alternative by another alternative by higher emission reduction
potential. This value is especially important when evaluating the
reasonableness of emission control costs. Table 8-13 shows the total
cost-effectiveness of each PM alternative control strategy. Note that
the cost-effectiveness of the three is approximately equalabout $100
per ton of PM emissions controlled. The incremental cost-effectiveness
of the low-efficiency ESP compared to that of the scrubber is shown
below:
Incremental «_im enn/w*.
roet- - $-101,600/yr 4-4fi4/ton
EffSiveness " 2iO tons/y/PM *««/»«
I-B-30
-------
Table B-ll. TOTAL AND INCREMENTAL OPERATING COSTS OF PM CONTROLS
(10% Annual Inflation Factor)
Alternative
Annual average cost
First 5 years operation ($l,000/yr)
Total
Incremental
High-efficiency ESP
Low-efficiency ESP
Scrubber (base case)
$229.8
160.9
325
$69.1
(164.5)
I-B-31
-------
Table B-12. ANNUALI2ED CAPITAL AND OPERATING COSTS OF PM
ALTERNATIVE CONTROL STRATEGIES
Total annual costs, $1000/yr
Alternative control strategy Total Incremental
High-efficiency ESP $442.3 $93.9
Low-efficiency ESP 348.4 (-101.6)
Scrubber 450
I-B-32
-------
Table B-13. TOTAL COST-EFFECTIVENESS OF THE PM
ALTERNATIVE CONTROL STRATEGIES
Alternative
control strategy Total cost-effectiveness
High-efficiency ESP 119
Low-efficiency ESP 87
Scrubber 106
1-8-33
-------
Since the low-efficiency ESP is estimated to cost about $100,000 less
per year than the scrubber, the incremental cost-effectiveness is negative
or "favorable" because the low-efficiency ESP will reduce PM emissions
by 210 more tons per year than the scrubber. Thus the low-efficiency
ESP will reduce more emissions at a lower cost. This finding is
significant.
The cost- effectiveness of the high-efficiency ESP versus the
low-efficiency ESP is shown below:
Incremental $g3
Cost" s
17Q
Effectiveness 17°
^
Note that the cost of reducing 1713 tons per year of PM emissions is
expected to cost more than five times the cost of the initial 3,990 tons
per year anticipated with the low-efficiency ESP. Thus a significant
economic penalty would be associated with controlling the additional
170 tons peryjear of PM that would be possible with the high-efficiency
ESP. To determine whether this additional economic burden is reasonable,
the air quality impacts of the residual PM emissions from the fluid
catalytic cracking unit must be assessed.
At this point, for several reasons, the applicant need no longer
consider the impacts "of the final PM emission control strategy based on
the venturi scrubber. First, the applicant has already demonstrated
that the scrubber is significantly more costly than either of the other
two alternative control strategies. Second, a quick screening reveals
that the scrubber has high ambient PM air quality impacts. Finally, the
scrubber controls PM emissions to a lesser degree than the other control
I-B-34
-------
and, furthermore, causes other adverse impacts. (It must be noted that
the applicant was not required to present the analysis for the venturi
scrubber since, at this point in the evaluation, it is not being considered
as BACT. The scrubber analysis was presented in this discussion to
demonstrate the decisionmaking process for evaluating alternative control
strategies.)
Now concentrating on the remaining two alternative control strategies,
the applicant assesses the relative ambient air impacts of PM emissions
by estimating stack parameters for these alternatives in order to create
input for a dispersion model. The modeling results show that, under the
worst-case meteorological conditions, the ambient impacts of PM of the
two alternatives are approximately equal5.9 vs. 5.4 micrograms per
cubic meter. Thus the higher incremental control cost of the high-
efficiency ESP cannot be justified on the basis of significant particulate
ambient air quality benefits. To determine BACT, the economic, energy,
and environmental impact analyses are evaluated against each other. The
results of the BACT analysis are summarized in Table B-14. In this
analysis, the applicant determines that the benefits of the high-efficiency
ESP are negligible compared to its higher costs and proposes the
low-efficiency ESP alternative control strategy as BACT for PM emissions.
Similarly, analyzing the CO emissions from the FCCU, the applicant
determines that high-temperature regeneration should be BACT based on
the high cost of waste gas incineration when compared to the relatively
small emission reduction it affords. Therefore, in this PSD application,
the applicant has proposed the following control strategies as BACT:
(1) a low-efficiency ESP for PM emissions, (2) high-temperature regeneration
for CO emissions, and (3) "no control" for NO emissions.
I-B-35
-------
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I-B-36
-------
NOTE:
Finally, it must be noted that the values presented in this example
were not based on established criteria of reasonableness and are used
only to demonstrate one example of the BACT decisionmaking process.
I-B-37
-------
-------
C. AIR QUALITY ANALYSIS
C.I INTRODUCTION
A key element of the PSD review process is the air quality analysis.
Before a PSD permit can be granted, the applicant must demonstrate that
neither a National Ambient Air Quality Standard (NAAQS) nor an allowable
PSD increment will be violated as a result of the emissions from a new
major source or major modification subject to the PSD requirements. An
air quality analysis must be conducted for each regulated pollutant
subject to PSD review that is expected to be emitted from, or whose
emission is expected to significantly increase in conjunction with,
proposed construction. Included are applicable pollutants for which
national ambient air quality standards exist, known as criteria pollu-
tants and other affected pollutants regulated by the Act, known as
noncriteria pollutants. An air quality analysis is also required in
certain cases involving insignificant pollutant emissions from sources
located near Class I areas.
It should be stressed that, although literature is available that
suggests methods of conducting an air quality analysis, no two analyses
are identical. A new major source in a remote area may need a rather
simple, straightforward air quality analysis, whereas a major modification
in a highly industrialized area would require a much more complex analysis.
I-C-1
-------
Because of the unique characteristics of each analysis, a quick solution
that will ensure the analysis adequately demonstrates compliance with
all standards and increments is not available.
However, by following the five.basic steps in an air quality analysis,
the requisite time and resources can be minimized. The five steps are:
1. Defining the impact area of the proposed major source or
major modification for each applicable pollutant,
2. Establishing appropriate inventories of each applicable
pollutant from all sources contributing to air quality in
the impact area,
3. Determining existing ambient air concentrations of those
pollutants,
4. Performing a screening analysis for each applicable
pollutant, and
5. Determining projected air quality resulting from emissions
of applicable pollutants.
Depending on the amounts and. types of regulated pollutants subject
to an air quality analysis, there may be as many as three separate but
interrelated phases of the analysis. They are:
1. To perform an increment consumption analysis for proposed
'sulfur dioxide (S02) and particulate matter (PM) emissions,
for comparison to allowable increments,
2. To determine existing air quality for all pollutants
subject to the air quality analysis, and
3. To analyze projected future air quality for all applicable
criteria pollutants and any applicable noncriteria pollu-
tants that the reviewing authority determines should be
evaluated. The purpose of this phase is to determine if
there will exist any NAAQS violation or very high ambient
concentration of noncriteria pollutants that may pose a
threat to health or welfare.
C.1.1 Total Ambient Air Concentrations and Allowable PSD Increment
Consumption
Before the air quality analysis can be studied in detail, the
relationship between total ambient air concentrations and allowable PSD
I-C-2
-------
increment consumption should be understood. Since allowable increments
exist only for S02 and total suspended particulates (TSP), this discussion
is confined to those pollutants. Total ambient concentrations of these
two pollutants consist of two components, baseline concentration and
increment concentration.
Baseline concentration is the adjusted ambient concentration at a
given location existing at the time after August 7, 1977 when the first
complete PSD application is submitted by a proposed major source or
major modification subject to EPA's PSD regulations as amended
August 7, 1980. The adjustment to this ambient concentration compensates
for the impacts of actual emission changes resulting from construction
at major stationary sources commencing after January 6, 1975. The
baseline concentration also includes projected emissions of major sources
commencing construction before January 6, 1975 but not in operation as of
the baseline date. Conversely, increment concentration is, in general,
that portion of ambient air concentration in an area which results from:
1. Emission increases and decreases at major stationary
sources resulting from construction that began after
January 6, 1975, and
2. Emission increases and decreases at all stationary sources
occurring after the baseline date. >i<
In general, increment consumption and expansion are based on actual
emissions. However, if little or no operating data are available, as in
the case of permitted emissions units not in operation at the time of
the increment analysis, the allowable emission rate must be used. In
addition, if allowable emissions are the result of a case-by-case new
source review, the PSD applicant may presume, subject to the approval of
, , L -_- , 4. ^
I-C-3
-------
the reviewing agency, that allowable emissions may be used to represent
actual emissions.
Since total air quality is the sum of baseline and increment
concentrations, knowing any two of these values will yield the third.
However, to obtain a permit, the PSD applicant need only demonstrate
that the proposed emissions in conjunction with other applicable emissions
will not cause or contribute to violations of two valuesthe allowable
increment and the national ambient air quality standards. Since both of
these demonstrations can be made without knowing the baseline concen-
tration, the need to determine baseline concentration is often not very
important.
For S02 and PM, both increment and total ambient concentration
standards exist for annual and 24-hour periods, as shown in Table C-l.
In addition, a 3-hour allowable increment and an NAAQS exist for S02.
The national ambient air quality standards are defined in terms of total
ambient pollutant concentrations that are not to be exceeded more than
once per year for other than an annual time period. Allowable increments
are defined as maximum allowable increases in ambient air concentrations
that are also not to be exceeded more than once per year for other than
an annual time period.
As indicated in the PSD regulations, all PSD areas have been classified
as either Class I, Class II, or Class III areas, and different allowable
increments of S02 and PM concentrations have been established for each
type of area. As Table C-2 shows, the most restrictive allowable increments
are for Class I areas, which are certain international and national parks
l-C-4
-------
Table C-l. ALLOWABLE CONCENTRATIONS FOR S02 AND PM
(ug/m3)
Controlling Class II
Pollutant/time period NAAQS Increment
Total Suspended
Particulate Matter
annual 75 19
24-hour 150a 37a
Sulfur Dioxide
0 annual 80 20
24-hour 365a 91a
3-hour l,300a 512a
Not to be exceeded more than once a year.
I-C-5
-------
Table C-2. ALLOWABLE PSD INCREMENTS
(ug/m3)
Class I Class II : Class III
Sulfur Dioxide
annual
24-hour
3- hour
Total Suspended
Part icu late Matter
annual
t 24- hour
2
5a
25a
5
10a
20
91a
512a
19
37a
40
182a
700a
37
75a '
aNot to be exceeded more than once a year.
I-C-6
-------
and wilderness areas. All other PSD areas have initially been designated
as Class II areas. Under certain conditions and with the concurrence of
its Governor and legislature, a State can designate a Class II area as
Class III and thereby allow greater potential for industrial growth.
Under no circumstances can air quality deteriorate beyond levels allowed
by the national ambient air quality standards, regardless of the area's
compliance status with applicable increments. An example is a Class II
area for which the annual S02 baseline concentration is determined to be
70 micrograms per cubic meter. Even though the allowable PSD increment
permits the annual S02 concentration to increase by 20 micrograms per
cubic meter, a PSD applicant must demonstrate that, as a result of
operation of the new major source or modification, the S02 concentration
in that area will not increase beyond the NAAQS of 80 micrograms per
cubic meter, an increase of only 10. On the other hand, if the annual
S02 baseline concentration in the area is only 40 micrograms per cubic
meter, the PSD applicant must demonstrate that S02 air quality will not
deteriorate beyond 60 micrograms per cubic meter in that area. In the
latter case, demonstration of compliance with the allowable PSD increments
also demonstrates that the NAAQS for annual S02 concentration will not
be violated.
C.I.2 Establishing the Baseline Area
As previously mentioned, the baseline concentration is established
in an area for a given pollutant as of the date after August 7, 1977 on
which a complete PSD application that is subject to the 1980 amended PSD
regulations is submitted. The baseline date is established for a given
pollutant only if the increase in emissions of that pollutant is
I-C-7
-------
significant. For instance, a PSD application for a new major source or
modification that proposes significant S02 emissions but insignificant
PM emissions will trigger the establishment of the S02 baseline date
only. Therefore, the baseline dates for S02 and total suspended PM may
be different in the same area.
The area in which the baseline date is triggered by a PSD permit
application is known as the baseline area. The extent of a baseline :
area is confined to intrastate areas and the area or areas designated as
attainment or unclassified under Section 107 of the Act in which the
proposed major source or major modification is located or will have a
significant impact. This baseline area includes all portions of any
Section 107 area that the source emissions affect. For this purpose,
such an impact is defined as at least a 1-microgranrper-cubic-meter
annual increase in ambient concentrations of the applicable pollutant.
Under Section 107 of the Act, all areas of the country have been given
either an attainment, a nonattainment, or an unclassified designation
for each criteria pollutant.
The fallowing example, illustrated in Figure C-l, demonstrates the
baseline concept. A new major source with significant S02 emissions
proposes to. Tocate in County C and submits a complete PSD application to
the appropriate review agency on October 6, 1978. A review of the S02
attainment designations reveals that attainment status is listed by
individual counties in the State. Since County C is designated attainment
for S02 and the source proposes to locate there, the baseline date for
S02 is therefore triggered for all portions of that county. Dispersion
I-C-8
-------
iMMl S02 Ezttlt tf
Sifiificiit lipict
County A
SO2 Attainment
Major Soiree
Trirrer SO, liseliae
*
County E
SO, Unclassified
County
SO, Unclassified
County D
S02 Attainment
X///A Baseline Date Triggered 10/6/78
Figure C-1. Baseline area: Example I.
I-C-9
-------
modeling of proposed S02 emissions in accordance with approved methods
reveals that the annual S02 impact area of the proposed source extends
into Counties A and B. The baseline date in all parts of these two
counties also is triggered on this date. Although S02 increment will be
consumed in the State to the north by the proposed emissions, the baseline
date remains untriggered unless it has been previously triggered by a
PSD permit application in that Section 107 area of the other State.
Note that increment-consuming emissions affect the increment concentration
at all places where they have an ambient impact regardless of the baseline
date, including out-of-state areas.
Most emissions changes that will affect increment will occur at
major stationary sources; therefore, the most significant date to con-
sider for increment tracking is January 6, 1975, the date after which
emissions resulting from construction at major stationary sources affect
the increment. Once triggered, the baseline date establishes the time
after which all other emissions changes at stationary sources affect the
increment. However, a State may propose and be granted the approval to
redesignate the boundaries of a Section 107 area. This action may
"untrigger" the baseline and thus reduce the inventory of emissions in
the redesignated area that affects increment. For instance, as shown in
Figure C-2, part of County A has been redesignated a separate Section 107
area after the baseline date had been triggered. If the baseline date
has not been established by another PSD application in the redesignated
portion of the area, the S02 emissions changes occurring after
October 6, 1978 from minor and area sources and nonconstruction-related
activities at all sources in this area will be transferred into the
I-C-10
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A ma i S02 Exteit of
Significant Impact
Major Soiree
TrijKf S02 liscline
*' z
SO, lAllalnment
County C
02 Attainment
County E
S02 Unclassified
County B
S02 Unclassified
fc* ^ ^ ^ . j
County D
S02 Attainment
\777A Baseline Date Triggered 10/6/78
Figure C-2. Baseline area: Example II.
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baseline concentration. In no event can any boundary of the redesignated
area intersect the line around the annual impact area of the source
triggering the baseline date.
C.2 ESTABLISHING THE IMPACT AREA
The previous example demonstrated the effect of the annual impact
«
area of a PSD source triggering the baseline date. For all sources and
modifications subject to PSD review, impact areas of applicable pollutants
should also be established, but for another reason. They should be
determined where the proposed emissions will have significant ambient
concentrations in order to determine compliance with applicable ambient
air standards and increments. The impact area should be established for
each applicable pollutant for each averaging time for which an NAAQS
exists. As shown in Figure C-3, the impact area is a circular area
whose radius is equal to the greatest distance from the source to which
approved dispersion modeling shows the proposed emissions will have a
significant impact. Table C-3 gives the values of significant ambient
air impacts.
Before continuing with impact area determination, the design heights
of stacks proposed to be constructed or to otherwise be used to emit
pollutants subject to the air quality analysis should be discussed. On
January 12, 1979, EPA proposed a good engineering practice stack height
rule, commonly known as GEP, which imposes limitations on the use of
excessively high stacks. Included in the proposed rule and its technical
criteria document are specific equations and methods to be used in
determining GEP stack heights. Unless the applicant can demonstrate by
acceptable methods that the stack or stacks must be constructed at a
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(pact Area
Eztett «f
Sigiificaii
(pact
Figure C-3. Impact area.
I-C-13
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Table C-3. SIGNIFICANCE LEVELS FOR AIR QUALITY IMPACTS
Averaging time
Annual, 24-hour, 8-hour, 3-hour, 1-hour,
Pollutant ug/m3 ug/m3 rag/m3 ug/m3 mg/m3
S02 1 5 25
TSP 15--
N02 :l
CO - - =0.5
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height that exceeds the height determined by the GEP formula, dispersion
modeling must be performed at the actual or GEP stack height, whichever
is lower. If a source proposes increasing existing stacks in conjunction
with a proposed modification, it may have to demonstrate through acceptable
methods (fluid modeling or field studies) that the additional height is
required in order to avoid excessive concentrations due to downwash.
If, on the other hand, the actual stack height is significantly less
than the GEP height, excessively high concentrations may result from
downwash. In such a case, the applicant should demonstrate in the
dispersion modeling that no violations of any increment or national
ambient air quality standards will result from downwash. The Huber-Snyder
downwash calculation method incorporated into some dispersion models is
an acceptable technique. Further revisions of the proposed GEP rule
must be followed, where applicable.
To properly establish the impact area, the PSD applicant should
consult the review agency dispersion modeling contact to receive concur-
rence on (1) selection of an appropriate dispersion model, (2) use of
adequate and representative meteorological data, and (3) techniques and
assumptions to be used in the analysis.
The latest revisions of the EPA documents Guideline on Air Qua!ity
Models and the Guidelines for Air Quality Maintenance Planning and Analysis,
Volume 10 serve as helpful guidelines for acceptable dispersion modeling
procedures. However, since no two scenarios are identical, it is the
PSD applicant's responsibility to receive review agency approval for
methods and procedures to be used in performing dispersion modeling.
Also, to avoid confusion, the applicant is encouraged to submit a
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dispersion modeling plan to the review agency for comment and concurrence
before conducting detailed analyses. Failure to do so may result in use
of improper or unacceptable techniques and may lead to serious delays
and wasted resources. The dispersion modeling plan should include at
least the following information:
Nature of proposed construction,
Pollutants to be modeled,
Site characteristics,
Topography within 50 kilometers of site,
Proposed dispersion model and meteorological data,
Proposed use of dispersion model options, and
Emissions data.
Determination of the impact area of proposed construction must
include all direct emissions including both stack and quantifiable
fugitive emissions of applicable pollutants. However, temporary emissions,
such as those related to construction, need not be considered.
The dispersion model input emission data should be based on the
worst-case condition for the time period of concern. The worst-case
condition is generally the maximum emission rate. However, depending on
operating and stack characteristics, the worst-case condition may not be
represented by the maximum emission rate; a simple hand calculation and
spot check can usually determine if it is.
The actual, measured meteorological data, if used, should be obtained
from either site-specific meteorological monitoring or the National
Weather Service station closest to the site. . If onsite data are used,
the selected period should be demonstrated to be typical of the area.
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If, for example, a chosen period indicates abnormally high amounts of
rainfall, the period may not be typical. If National Weather Service
information is used, 5 years of meteorological data will generally be
required for input into dispersion models.
C.3 ESTABLISHING THE EMISSIONS INVENTORIES
Generally, the applicant must compile an emissions inventory of
applicable criteria pollutants that have been demonstrated, as in the
previous step, to result in significant impacts. In addition, an inven-
tory of applicable noncriteria pollutants may be required to determine
if high concentrations of these pollutants exist or will exist that may
pose a threat to health or welfare. If preliminary dispersion modeling
demonstrates that proposed emissions of a criteria pollutant will have
no significant impacts, further air quality analysis of that pollutant
will generally not be required, unless the source is located near a
Class I area. In such a case, an air quality analysis of the pollutant
may be required if the proposed emissions are expected to exceed
1 microgram per cubic meter on a 24-hour basis in the Class I area.
Depending on the specific pollutant predicted to result in a
significant impact, three inventories of emissions may have to be
established:
1. An inventory of increment-consuming PM or S02 emissions.
2. An inventory of all existing emissions of applicable
pollutants having an effect on air quality in the impact
area of the proposed emissions.
3. An emissions inventory of applicable pollutants from
permitted emissions units not yet operating that may have
an effect on air quality in the impact area.
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If an air quality analysis is required for PM and S02 emissions,
and both pollutants are predicted to have significant impacts, an increment
inventory should consist of all PM and S02 increment-consuming emissions
within the impact area and those emissions outside the impact area that
may have a significant impact within the impact area. Thus a PSD applicant
may have to consider large sources as much away as 50 kilometers outside
his or her other impact area for increment-consuming emissions. Generally,
on a short-term basis, such as a 24-hour or a 3-hour period, the PSD
applicant need only identify those increment-consuming emissions within
the respective impact area. However, for annual impact determinations,
large emission sources located as far as 50 kilometers from the impact
area may have impacts within the applicant's impact area.
As shown in Figure C-4, the annular ring outside the impact area is
called the screening area. In determining which emissions sources in
the screening area should be added to the emissions inventory, the
applicant should consider three criteria: (1) annual emissions of the
source, (2) degree of ambient impact, and (3) distance from the impact
area. For example, a 100-ton-per-year source located 10 kilometers from
the impact area generally can be excluded from the inventory because its
effect on air quality in the impact area is expected to be insignificant.
However, a 10,000-ton-per-year source located 40 kilometers from the
impact area would probably have to be accounted for in the increment
analysis. A simple screening model technique can be used to justify the
exclusion of certain emissions from this analysis. Such exclusions
should be justified and documented.
After identifying the emissions units to be included in the emissions
inventory, the emission rates must be determined for input into the
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Figure C-4. Emissions inventory screening area,
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proper dispersion model. Although allowable PSD increment consumption
is based on actual emissions, the first attempt at performing the increment
analysis should be based on allowable emissions. There are two reasons
for this:
1. Allowable emissions rates are more readily available from
State emission files, and
2. The resulting analysis will be more conservative.
State air emission files are the proper source of emissions
information.. If dispersion modeling with allowable emissions cannot
demonstrate-compliance with allowable PSD increment consumption, the
applicant should then obtain actual emissions data. This information
must be thoroughly documented and may be obtained through discussions
with State agency personnel and source contacts.
Emissions inventories for the last two categories are for the
purpose of demonstrating compliance with the applicable NAAQS and should
be gathered and compiled in a similar manner to the increment emissions
inventory. For existing sources, this inventory should be based on
actual emissions if data are available. Actual emissions should be used
in this case to reflect the impact that would be detected by ambient air
monitors. In. the case of permitted emissions units not yet operating,
the only alternative is to use the allowable emission rate.
C.4 DETERMINING EXISTING AMBIENT CONCENTRATIONS
Perhaps-one of the most critical aspects of PSD review is the
requirement for the source owner to provide up to 1 year of preconstruc-
tion monitoring data. This requirement applies to all applicable criteria
pollutants (with the exception of nonmethane hydrocarbons) that the
I-C-20
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source would emit in significant amounts, although it may apply to some
noncriteria pollutants as well. Generally, continuous ambient air
monitoring data will be required for all criteria pollutants for which
there will be a significant increase in emissions. If, however, predicted
impacts or existing air quality in the source's impact area are less
than the values indicated in paragraph (i) of the PSD regulations, then,
at the Administrator's discretion, site-specific monitoring may not be
required. Therefore, the first step in determining monitoring requirements
is to estimate source impacts on the air quality and to determine the
total existing air quality in the area.
A PSD applicant can satisfy the monitoring requirement in two ways.
First, under certain conditions, the applicant may rely on existing
continuous monitoring data collected by Federal, State, or local air
pollution control agencies. Secondly, the applicant may conduct
site-specific monitoring for those pollutants that the proposed source
would emit in significant amounts. EPA has published specific guidelines
for a PSD applicant in the latest revision of Ambient Monitoring Guidelines
for Prevention of Significant Deterioration. Meteorological monitoring
is generally required when conducting site-specific monitoring and
should be used in the subsequent dispersion modeling analysis.
Before using existing data, the applicant must first verify that
the data meet certain criteria. These criteria are (1) data sufficiency
or completeness, (2) data representativeness, and (3) data reliability.
Although State and local agencies have generally monitored ambient air
quality for several years, all the data collected are not adequate for
the preconstruction analysis required under PSD. The ambient monitoring
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guidelines and the PSD review agency should be consulted for the minimum
requirements on the usefulness of the data.
In a case in which site-specific monitoring is required of an
applicant, the requirements focus on site selection and quality assurance.
The site selection process involves dispersion modeling analyses of
existing sources and of the proposed emissions to determine the most
appropriate areas within the impact area of the proposed emissions to :
locate ambient air monitors. The applicant should reach agreement with
the permit-granting authority on the number and locations of the monitors
before monitoring operations are begun.
The primary requirement in conducting site-specific monitoring .is
that the owner or operator of the proposed source meet the gualitv_
assurance^requirements of Appendix B to 40 CFR Part 58 during the opera-
tion of monitoring stations. Appendix B requires that the quality
control program developed by the organization operating the monitoring
network be described in detail, be suitably documented, and be approved
by the permit-granting authority.
Long before a monitoring program begins, the PSD applicant should
submit a monitoring plan to the permit-granting authority for comment
and approval. The monitoring plan should include, at a minimum, a
discussion of the following items: (1) the network description,
(2) monitor site description, (3) monitor description, (4) sampling
program description, and (5) quality assurance program. EPA's guidelines
on PSD monitoring describe these requirements in greater detail.
Having collected and screened the data., the applicant should integrate
the results of the monitoring into the air quality analysis. The amount
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of data and manner of presentation in the application depend on the
requirements of the permit-granting authority. At a minimum, the data
should be presented in a summary format showing highest and highest,
second highest concentrations for pollutants with short-term standards
and the appropriate long-term average associated with each standard.
These concentrations effectively describe the existing ambient concen-
trations within the impact area attributable to actual emissions from
existing sources.
In many cases, monitoring data may require adjustment to compensate
for new emissions permitted in the impact area but not occurring during
the monitoring period. The emissions inventory used for adjusting the
monitoring data should be gathered as previously described and should be
used to adjust the monitoring data by proper dispersion modeling procedures.
C.5 PERFORMING THE SCREENING ANALYSIS
As discussed in the Guideli ne on Ai r Qua1ity Models. a screening
modeling analysis is recommended before a refined analysis is conducted.
The screening analysis will primarily provide the PSD applicant with
these essential data:
1. An approximation of the maximum downwind impacts,
2. A general idea of the location of the maximum impacts,
and
3. Quick preliminary results.
As in the impact area determination, both quantifiable fugitive emissions
and stack emissions should be included in the screening analysis. In
addition, if secondary emissions are quantifiable and are expected to
affect the air quality in the impact area, they should also be included
in the screening analysis.
I-C-23
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The applicant must remember that the same GEP stack height criteria
mentioned earlier also apply in the screening analysis and in any refined
dispersion modeling analysis.
If the results of the screening analysis indicate that any increment
or standard may be threatened, a refined dispersion modeling analysis
should be conducted. A refined analysis must be conducted when screening
results indicate total increment will be consumed or that total projected
air quality will exceed 100 percent of its respective standard. How-
ever, if results do not exceed this 100-percent value, then these values
may be used, subject to approval by the reviewing agency, to represent a
conservative projection of total air quality and increment consumption.
C.6 DETERMINING PROJECTED AIR QUALITY
If, however, a refined analysis is required, the procedures described
in the Guideline on Air Quality Models and the Guideline for Air Quality
Maintenance Planning and Analyses, Volume 10 should be strictly followed.
The applicant is advised to work closely with the review agency modeling
contact durfng this process.
The refined dispersion modeling analysis will use the emissions
inventory and all other data gathered up through the screening analysis.
Many techniques and assumptions are available to assist the PSO applicants
in the refined analysis. However, before performing elaborate and
expensive tasks, the applicant is advised to secure the approval of the
appropriate review agency modeling contact before assuming his or her
techniques are valid for the particular case.
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C.7 OTHER MODELING CONSIDERATIONS
In many cases, special considerations may arise that require particular
attention. Such considerations include use of an alternative dispersion
model that may be more appropriate for a specific analysis, for performing
a dispersion modeling analysis in complex terrain, or for modeling
nonpoint sources of emissions. Again, the PSD applicant is advised to
work closely with the review agency modeling contact. If a modeling
plan is to be submitted, these issues and proposed alternatives should
be highlighted and discussed in the plan.
C.8 AIR QUALITY ANALYSIS EXAMPLE
All applications for a PSD permit subject to the requirements of
the air quality impact analysis must include complete and accurate
analyses to ensure compliance with the national ambient, air quality
standards and the PSD increments. To demonstrate compliance, the
applicant should:
I. Define the impact area,
2. Compile an emissions inventory,
3. Determine existing air quality,
4. Perform a screening analysis, and
5. Determine the projected air quality.
This subsection applies those procedures to a hypothetical situation.
The presentation of an example is difficult, because no two analyses are
alike. An example that covers all possible modeling scenarios is impossible
to present; however, in this example, several significant elements of
the air quality analysis will be analyzed.
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In the applicability example, an applicant proposed the construction
of a new coal-fired, steam electric-generating station. This example is
now extended to include thfe air quality analysis that might be conducted
by the applicant. The coal-fired station is a new major source with
significant emissions of S02, PM, nitrogen oxide (NO ), and carbon
monoxide (CO). An air quality impact analysis must be prepared for each
of these pollutants, as indicated in the applicability example. In the
analysis, concentrations for all four pollutants will be examined with
respect to the NAAQS. The PSD increments for TSP and S02 will also be
considered.
C.8.1 Definition of Impact Area
The first step in the analysis is to establish the impact areas for
each pollutant. As a conservative approach, these can be defined as a
circular area whose radius is equal to the greatest distance to which
approved dtspersion modeling shows the proposed emissions will have a
significant impact. An impact area is predicted for each averaging
period for each pollutant and the largest impact area for a given pollutant
is selected as the impact area to be used in the air quality analysis.
The modeling procedures used were determined to be in accordance with
the procedures described in the Guideline on Air Quality Models and have
been reviewed in advance by the appropriate modeling contact.
Several- emissions units at the source will emit pollutants subject
to the air quality analysis. First, of course, are the two main boilers
that emit PM, S02, NO , and CO. A standby auxiliary boiler will also
A
emit these pollutants, but only when the main boilers are not operating.
I-C-26
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PM will also be emitted from coal-hand!ing operations and from the
limestone preparation process for the flue gas desulfurization (FGD)
system. Emissions units associated with coal and limestone handling
include:
Point sourcesthe coal car dump, the fly ash silos, and
the three coal baghouse collectors;
Area sourcesthe active and the inactive coal storage
piles and the limestone storage pile; and
Line sourcesthe coal and limestone conveying operation.
Emissions units to be included in the impact area determination include
the allowable emissions at the boiler stacks and fugitive emissions of
PM associated with the power plant.
The results of the impact area analysis indicated that significant
ambient impacts of NO and S02 extend to 32 and 50 kilometers, respectively.
. J\
An impact area did not exist for CO because concentrations at all location?
off the property were insignificant. Becaue of this, no further CO
analysis was required. PM emissions caused a 2.2-kilometer impact area
predominantly due to fugitive emissions.
Fugitive emissions from the adjacent mine are not considered in the
impact area determination because they are considered secondary emissions;
they must, however, be considered in the increment and NAAQS analysis.
C.8.2 Establishing an Emissions Inventory
With the impact area analysis complete, the applicant proceeded to
establish three emissions inventories. The first was an inventory of
existing sources that contributed to existing ambient air quality as
measured by the continuous monitoring data collected for the air quality
review. Dispersion modeling of this inventory was used to demonstrate
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that the continuous monitors were properly located. Source and emissions
data for this inventory were extracted from State air permit and emissions
inventory files.
The second inventory would have included those sources that were
permitted to operate, but were not operational when the monitoring data
were collected. However, no such sources were identified. Therefore,
an inventory need not be established to correct the ambient monitoring
data.
The third required inventory is the inventory of emissions that
affect increment. It includes all increment emissions from sources
within the impact area and those from sources outside the impact area
that have been demonstrated to significantly affect the impact area.
The establishment of the increment inventory requires that the baseline
date be determined.
In this area of the State, S02 and TSP attainment status designations
are listed by individual counties. Four counties are covered by the
area within 100 kilometers of the proposed power plant, as shown in
Figure C-5. A review of PSD application information revealed that the
baseline dates for both S02 and TSP had been established in Counties A
and B on November 2, 1977. However, the baseline date had not been
previously established in Counties C and D. Therefore, in compiling the
increment inventory, PM and S02 emissions occurring at minor and area
sources located in Counties C and D were not considered. Similarly,
emissions changes resulting from nonconstruction-related activities at
major sources in these counties were also ignored. However, the State
air permit and emission inventory files were searched for these types
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Proposed
Power Plant
Figure C-5. Counties within 100 kilometers of proposed power plant;
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of emissions changes in Counties A and B. No such emission changes were
determined to have occurred since November 2, 1977. Regardless of
baseline date, the increment inventory for S02 and PM included emissions
changes at major sources resulting from construction commencing after
January 6, 1975. The State and Federal air permit files were searched
for sources in the latter category. The following sources were found:
the associate lignite mine, Refinery A, Chemical Plant B, Petrochemical
Complex C, Rock Crusher D, and Refinery £.
Additionally, a Portland cement plant, Plant F, lies just outside
the S02 impact area about 70 kilometers northwest of the source. The
only other source in the TSP impact area is the proposed lignite mine.
A plot of these sources is shown in Figure C-6.
C.8.3 Establishing Existing Air Quality
The next step in the air quality analysis is to determine the
existing a,ir quality for applicable pollutants, which, in this example,
are S02, NO , and PM. CO was eliminated from consideration because
A
ambient impacts from the proposed source will be less than the monitoring
significance level of 575 micrograms per cubic meter on an 8-hour average.
An exemptton from the monitoring requirement for CO was granted by the
review agency. The other pollutant impacts and estimated existing ambient
concentrations were above monitoring significance levels.
Before undertaking a site-specific monitoring program, the applicant
first evaluated the use of existing continuous monitoring data collected
by the State. For this example, the applicant contacted the State
agency and found that the State operated a continuous monitoring station
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Portland Cement
Plant F
0 km radius
Refinery A
Chemical
Plant B
Rock Crusher D
Refinery E
Lignite
Mine
Proposed
Power Plant
Petrochemica
/Complex C
Regional
Airport
Figure C-6. Geographic location of sources,
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near the regional airport. The station had been deployed 2 years before
to measure the combined impacts from the sources located in the southwest
quadrant of the proposed power plant's impact area. It was now to be
demonstrated that the data met the criteria for (1) data sufficiency,
(2) data representativeness, and (3) data reliability. An initial
review of the data obtained from the State agency's data files revealed
that continuous data were available for the preceding 2 years for all
criteria pollutants.
The analysis of the data was conducted in accordance with procedures
outlined in Ambient Monitoring Guidelines for Prevention of Significant
Deterioration. The data sufficiency was established with an analysis of
the extent of data capture. A modeling analysis using methods outlined
in the Guideline on Air Quality Models was performed to show that the
monitor was properly located to measure peak concentrations in the
source impact area; it was therefore determined that the data represented
the locatfons where maxima would occur.
Conversations with the State agency's monitoring representative
revealed that measurements for all criteria pollutants were conducted
using EPA reference or equivalent methods and that the State's quality
assurance program exceeded the minimum quality assurance requirements of
Appendix B 40 CFR Part 58. Review of the results from independent
audits performed on each of the monitors revealed that the accuracy for
all analyzers was within acceptable limits. Therefore, the data were
felt to be a reliable and accurate representation of existing air quality
levels.
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In summary, the data collected by the State agency near the regional
airport were evaluated for data sufficiency, representativeness, and
reliability. The analysis of the data with respect to each of the
preceding criteria indicated that the data were appropriate for inclusion
in the air quality analysis, thus satisfying the PSD preconstruction
monitoring requirement. The data further indicated that air quality
levels within the power plant's impact area were well within the applicable
NAAQS for all averaging times.
As previously mentioned, it was found that no sources had commenced
construction or operation since the monitoring data collection for the
preceding year began. Therefore, the monitored air quality levels were
established as representing existing air quality in the impact areas of
the proposed source. As shown in Table C-4, demonstration of compliance
with tne increments for TSP and S02 will ensure compliance with the
respective NAAQS. The 24-hour TSP concentration is considered as an
example. Based on the conservative assumption that all of the 24-hour
TSP increment is available, the total possible future TSP air quality
level could reach only 146 micrograms per cubic meter if no violations
of the TSP increment occur. Similarly, for each averaging time for TSP
and S02, the same rationale can be used. This is a conservative analysis,
because undoubtedly some of the increment-consuming sources were measured
by the continuous monitors. As a result of the simplification, only the
following analyses require completion:
1. the S02 increment analysis,
2. the TSP increment analysis, and
3. the nitrogen dioxide (N02) total air quality analysis.
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Table C-4. CONSERVATIVE DEMONSTRATION OF COMPLIANCE WITH NAAQS
TSP
24-hour
annual .
S02
3-hour
24- hour
t annual
Existing
air quality
109
49
358
99
14
Allowable
i ncrement
37
19
512
91
20
Total
possible
air quality
146
68
870
190
34
NAAQS
150
75
1,300
365
80
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The required increment analysis consisted of modeling the impacts
from the proposed sources together with impacts from the other six
existing increment-consuming sources. For convenience, the allowable
emissions of these six sources were initially assumed to represent
actual emissions.
C.8.4 Screening Analysis
A screening analysis was not performed because experience has shown
that a refined analysis will generally be required for a modeling situation
involving large power plants such as this one. Therefore, the applicant
proceeded directly to the refined analysis.
C.8.5 Model Air Quality and Increment Consumption
Once the impact area is defined, the inventory is established, and
existing air quality data are gathered, the modeling analyses may begin.
Steps in the modeling process include:
1. Selection of appropriate models,
2. Selection of meteorology,
3. Selection of critical meteorology,
4. Consideration of stack heights with respect to good
engineering practice, and
5. Analysis of fugitive emissions.
The area within 3 kilometers of the proposed source was determined
to be a rural area based upon a land-use study. For the short-term S02
modeling analyses, an appropriate model was selected based upon recommen-
dations in the Guideline on Air Quality Models. It can be used to model
short-term concentrations of S02 in a multiple-source rural environment.
Next, the meteorological data inputs to the model were collected.
Because no onsite meteorological data were available, data from the
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nearest National Weather Service station (located at the regional airport)
were gathered. Five years of hourly observations from 1975 to 1979 were
used.
The auxiliary boiler was eliminated from further modeling considerations
because it would not be permitted to operate when either of the main
boilers were at sufficient load to provide plant steam requirements. A
single-source model run for this emissions unit showed that its maximum.
ground-level impacts were insignificant so that it could not possibly
contribute to violations of any air quality standard.
The next step was to perform the actual modeling for S02 emissions.
As a conservative first attempt, the allowable emissions of all sources
were modeled. Screening for critical meteorology and areas of expected
peak concentrations was performed in accordance with the procedures
outlined in the Guideline on Air Quality Models. The modeling was then
repeated wittr a dense receptor grid with spacing of 100 meters in the
areas where maximum concentrations were expected, as indicated from the
results of the- screening analysis.
A review of the results shows that, in the case of peak concentrations
downwind of the southwest source conglomeration, the allowable S02
increment will be exceeded by 7 micrograms per cubic meter during the
critical 24-hour averaging period. The violation includes significant
impacts from the proposed power plant. Further analysis revealed that
the chemical plant in the southwest quadrant was the major contributor
to the receptors where it was predicted that the increment would be
exceeded.
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As a result of the predicted S02 violation, the permit may be
denied. At this point, there are two options available to the power
plant. First, additional controls beyond the level of control proposed
as best available control technology (BACT) can be applied to decrease
the size of the source impact area so that the increment violation is no
longer in the impact area.
Secondly, actual emissions can be determined at the southwest
source conglomerate. If there is a significant difference between
actual and allowable emissions, modeling can then be performed using the
actual rather than the allowable emissions. For this example, the
power plant chose the latter option. Representatives of the proposed
power plant contacted the State air pollution authorities as well as
representatives of the industries in the southwest conglomeration.
Inquiries revealed that the boiler at the chemical plant was permitted
to burn oil with a sulfur content of 0.7 percent. It was further
discovered that the boiler has burned natural gas rather than oil since
1977, when a dependable natural gas supply was secured. This was sub-
, stantiated by the annual emission reports on file with the State air
1 pollution agency. The actual emissions at the chemical plant based upon
the use of natural gas during the preceding 2 years revealed a substan-
tial difference between actual and allowable emissions. The applicant
then modeled actual emissions at the chemical plant and allowable emissions
for the refineries and the proposed power plant. Modeling was repeated
^ for the critical periods.
The revised modeling demonstrated compliance with the allowable
increment, and, therefore, no further short-term S02 modeling was required.
-r-V^. *« ^'7 j.c.37
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The maximum predicted S02 increment concentrations were 72 and 302 for
the: 24- and 3-hour averages, respectively.
The same S02 emissions data were used for input to the appropriate
dispersion model for prediction of annual ambient S02 impacts. NO will
be emitted from the same stacks as S02 emissions, and the proposed
allowable emissions of both pollutants are identical. Making the conser-
vative assumption that all N0x will be emitted as N02, then the impacts
of these pollutants were assumed to be identical. Because the proposed
source is located in a predominantly rural area, a multiple-source rural
model was selected.
A conservative first analysis was begun using the allowable emissions
from the short-term analysis. The meteorology referred to earlier was
also used. The results show no violations of any annual standard.
C.8.5 Particulate Hatter
With the N02 and S02 analyses complete, the only remaining analysis
required is the demonstration of compliance with the TSP increments and
the NAAQS. Note that fugitive PM emissions from the lignite mine,
although considered secondary, must be considered in evaluating the
total air quality and the impact on allowable TSP increment. As indicated
previously, compliance with the TSP increments will ensure compliance
with the NAAQS. Therefore, the emissions units associated with the
source include the two main boilers, fugitive emissions at the power
plant, and the lignite mine. A multiple-source rural model was selected
from the Guideline on Air Quality Models that adequately predicts the
effects -of fugitive emissions in addition to those of the point sources.
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For the short-term analysis of PM emissions impact, only those
emissions from the power plant and the mine needed to be considered. PM
emissions from the other five sources within 50 kilometers of the impact
area were shown not to significantly affect the TSP increment in the
proposed source's impact area. In this case, the same 5-year period of
meteorological data used for S02 modeling was input to the selected
model with the proposed PM emissions from all emissions units. The
results of the analysis show that the maximum predicted 24-hour PM
increment concentration was 28 micrograms per cubic meter, which is
within the allowable increment of 37. Therefore, the short-term analysis
for PM is complete. Similarly, a long-term modeling analysis showed no
violations of the annual TSP increment. Maximum annual PM impacts were
predicted to be 13 micrograms per cubic meter.
The only remaining task for the analysis was to summarize the
results and describe the analysis. As shown in Table C-5, no NAAQS or
increment ir expected to be violated as a result of the emissions of the
power plant and associated mine. Recommendations for data format are
available in the Guideline on Air Quality Models.
This example has shown that a comprehensive air quality modeling
analysis requfres a good understanding of modeling principles, PSD
applicability, and the emissions established in the BACT analysis.
An air quality modeling analysis begins with the establishment of
an impact area and an emissions inventory. Existing air quality is
determined, ancLa screening analysis is conducted. The increment consump-
tion and total air quality within the impact area are predicted in the
final steps of the air quality analysis. A comprehensive, well-organized
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air quality modeling analysis is essential to the PSD permitting process
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quality.
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D. ADDITIONAL IMPACTS ANALYSIS
All applicants requiring a PSD permit must prepare an additional
impacts analysis for each pollutant subject to review. This analysis is
concerned with determining the air pollution impacts on soils, vegetation,
and visibility caused by emissions from the source or modification under
review, and the emissions resulting from associated growth.
D.I DEFINITION AND PURPOSE
The purpose of this section is to help the PSD applicant fully
consider those factors that are relevant to a complete additional impacts
analysis. This section also offers suggestions as to what kind of
analysis, organization, and method could most satisfactorily meet all
PSD requirements, and to what degree the analyses should be performed.
There are three basic purposes of an additional impacts analysis:
1. To determine the effects of emissions of applicable
criteria and noncriteria pollutants to assist in best
available control technology (BACT) decisionmaking,
2. To inform the general public of potential air quality-related
impacts; and
3. To. help provide the Federal land manager with information
regarding potential impacts on Class I areas.
Several points regarding the overall direction of the entire analysis
must be kept fn mind by the applicant:
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1. Although every applicant for a PSD permit must perform an
additional impacts analysis, the depth of the analysis is generally
dependent upon the quantity of emissions, the existing air quality, and
the sensitivity of those emissions on local factors such as soils,
vegetation, and visibility. The need for a rigorous additional impacts
analysis is aimed primarily at those new major sources and major modifi-
cations that may reasonably be expected to result in significant impacts
on these factors.
It is expected that small emissions increases in an area will not
produce any major impacts on soils, vegetation, and visibility; however,
the impact areas of new major sources and major modifications must be
surveyed to verify and document the anticipation of "no significant
impact."
2. Public information is a primary goal of the additional impacts
analysis. Therefore, the applicant should prepare an analysis that wfll
provide the public with an assessment of the relevant potential environ-
mental air pollution impacts that may occur in the area affected by
emissions of pollutants subject to review. The applicant should be
particularly aware that any potential air pollution impacts on Class I
areas are especially important and that these impacts should be assessed
thoroughly.
3. An additional impacts analysis is triggered for those pollutants
that will be emitted or increased in significant quantities. Thus. both,
criteria and noncriteria pollutants may cause the applicant to undertake
an additional impacts analysis.
4. An additional impacts analysis is concerned with the air pollution.
effects on soils, vegetation, and visibility. This examination generally
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requires an analysis of the projected ambient air concentrations and a
correlation to potential impacts on these factors. The analysis must
encompass potential impacts of direct emissions from the new major
source or major modification and secondary emissions from associated
residential, commercial, or industrial growth.
5. It is important that the analysis be fully documented. A PSD
applicant must remember that an additional impacts analysis is, by
definition, an analysis, and therefore, all conclusions should be
carefully and sufficiently documented.
6. While this section offers applicants a basic method of approaching
an additional impacts analysis, it must be stressed that no "hard and
fast" formula, format, or "cookbook" approach to an additional impacts
analysis exists. Regarding the analysis, what is most important is that
all significant factors and the resulting impacts are recognized and
carefully analyzed.
With these points in mind, an applicant can proceed in considering
the following overview of the additional impacts analysis components.
D.2 FORMAT FOR THE ADDITIONAL IMPACTS ANALYSIS
The additional impacts analysis is made up of three component
analyses: (1) a growth analysis, (2) a soils and vegetation impact
analysis, and (3) a visibility impairment analysis.
D.2.1 Growth Analysis
The growth analysis is considered first, before the other components,
because it provides information essential to the other component analyses.
The elements of the growth analysis follow:
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1. A projection of the associated industrial> commercial, and
residential growth that will occur in the area.
2. An estimate of the air pollution emissions generated by associated
permanent growth.
3. An air quality analysis which includes these estimates. The
results from this analysis become the basis for determining the extent
of the air pollution impacts in the impact area.
To determine the first element in the growth analysis, which is the
projection of associated growth for the impact area, the applicant first
should consider the availability of two types of support factors, local
support factors and industrial support factors. Local support factors
include situations such as the area's ability to house new employees and
the commercial industries presently existing within the area that are
available to support residential growth. For example, a large new major M±
source that causes a permanent population growth may result in housing
developments and associated air emissions. Examples of industrial
support factors include industries that provide goods and services
related to the source or modification. These types of industries include
large industries providing raw materials and smaller industries providing
maintenance and other support. For instance, a new major source using
coal for fuel may attract coal mining operations for support.
Information on local and industrial support factors is readily
available and can be obtained from State agencies, regional planning
offices, the local Chamber of Commerce, through information contained in
environmental impact statements, and in PSD applications previously
prepared by other applicants.
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After the applicant has assessed the availability of residential,
commercial, and industrial services existing in the area, the next step
is to predict how much new growth must occur to support the source or
modification under review. The amount of residential growth will be
dependent on the size of the available work force, the number of new
employees, and the availability of housing in the area. Industrial
growth is growth in those industries providing goods and services,
maintenance facilities, and other large industries necessary for the
operation of the source or modification under review.
Having completed this portrait of expected growth, the applicant
then begins developing an estimate of the air pollution which likely
would evolve from permanent residential, commercial, and industrial
growth. Excluded from consideration are emissions from temporary sources
and mobile sources. The applicant should generate emissions estimates
by consulting such sources as manufacturer's specifications and guidelines,
AP-42, other PSD applications, and comparisons with existing facilities.
The applicant arrives at an analysis of projected air quality by
taking the air pollution estimates from all the variables of growth
already surveyed and then combining these estimates with the estimates
of applicable pollutant emissions that are expected to be produced
directly by the source or modification. The combined estimate, through
the modeling process, serves as the input to the air quality analysis,
and what emerges is a prediction of the ground-level concentration of
pollutants generated by the source and any associated growth.
D.2.2 Soils and Vegetation Analysis
The manifestations of air pollution impacts on soils and vegetation
can be seen in such occurrences as premature bud loss, failure of flowering,
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leaf necrosis, and plant death. At high ambient concentrations, these
acute affects can appear readily. However, many deleterious effects
that are due to subtle but chronic exposure to pollutants over a long
period of time also occur. Such time-delayed impacts can ultimately
prove to be the most harmful.
A suggested informational basis for an analysis of air pollution
impacts may be obtained by conducting a survey of the soil and vegetation
types found in the impact area. This survey should include all vegetation
with any commercial or recreational value. Surveys of this nature
usually have been performed for the area and are readily available from
conservation groups, State agencies, and universities. This comprehensive
listing of soils and vegetation types then would allow the applicant to
determine air pollution impacts by utilizing the method discussed below.
The modeling results of the air quality analysis, conducted to
demonstrate compliance with national ambient air quality standards, will
provide the applicant with estimates of the maximum ambient air concen-
trations for criteria pollutants under review in the impact area. For
applicable noncriteria pollutants, the applicant should project future
ambient air concentrations in accordance with the procedures outlined in
the air quality analysis section in Section C. By consulting scientific
literature, the applicant can assess the impacts of applicable pollutants
on the soils and vegetation types in the impact area. The applicant can
determine these impacts by correlating the known ambient air concentrations
of pollutants with the types of soil and vegetation found in the survey
of the area. The applicant should document all conclusions.
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For roost types of soils and vegetation, ambient air concentrations
of criteria pollutants below the national ambient air quality standard
(NAAQS) will not result in harmful effects. However, there are sensitive
vegetation species and soil types that may experience harmful effects at
low ambient air concentrations (i.e., soybeans and alfalfa). For this
reason, the suggested initial soil and vegetation survey serves as an
important basis for the analysis.
Noncriteria pollutants can result in harmful affects at generally
Vower concentrations^than the criteria pollutants. For example, exposure
of sensitive plant species to 0.5 micrograms per cubic meter of fluorides
for 30 days has proven to result in significant foliar necrosis.
D.2.3 Visibility Impairments Analysis
In the visibility impairments analysis, the applicant is ^specially
concerned with Class I area impacts, as well as with impacts that occur
within the area affected by applicable emissions. The Clean Air Act
specifically requires plans and procedures for maintaining the visual
quality within Class I areas. The suggested components of a good
visibility impairments analysis are:
1. An initial screening of emission sources that examines the
possibility of visibility impairment.
2. If warranted, a more in-depth analysis involving computer
models.
3. A determination of the visual quality of the area.
To successfully complete a visibility impairments analysis, the
applicant is referred to a draft EPA document (July 1980) entitled
"Workbook for Estimating Visibility Impairment." Although this is a
draft document, this workbook can be used as general .guidance. In this
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workbook, EPA outlines a screening procedure designed to expedite the
analysis of emissions impacts on the visual quality of an area. The
workbook was designed for Class I area impacts; however, the outlined
procedures are generally applicable to other areas as well. The following
sections are a brief synopsis of the screening procedures.
D.2.3.1 Screening Procedures: Level 1. The Level 1 visibility
screening analysis is a series of conservative calculations designed to
identify those emission sources that have little potential of adversely
affecting visibility. Calculated values relating source emissions to
visibility impacts are compared to a standardized screening value.
Those sources.with calculated values greater than the screening criteria
are judged to have potential visibility impairments. If potential
visibility impairments are indicated, then the Level 2 analysis is
undertaken.
D.2.3.2 Screening Procedures: Level 2. The Level 2 screening
procedure is similar to the Level 1 analysis in that its purpose is to
estimate impacts during worst-case meteorological conditions; however,
more specific information regarding the source, topography, regional
visual range, and meteorological conditions is assumed to be available.
The analysis may be performed with the aid of either hand calculations,
reference tables, and figures, or a computer-based visibility model
called the "plume visibility model."
D.2.3.3 Screening Procedures: Level 3. If the Level 1 and 2
screening analysis indicated the possibility of visibility impairment, a
more detailed analysis is undertaken in Level 3 with the aid of the
plume visibility model and meteorological and other regional data. The
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purpose of the Level 3 analysis is to provide an accurate description of
the magnitude and frequency of occurrence of impact.
The procedures for utilizing the plume visibility model are described
in the draft document entitled "User's Manual for the Plume Visibility
Model," which is available from EPA.
To complete the visibility impairment analysis, the applicant is
urged to provide a description of the visual quality of the area, which
should include a discussion of any scenic vista in the area that may
have public appeal or aesthetic value. What constitutes "scenic" and
"aesthetic" is always open to the consideration of differing tastes.
However, a broad consensus does exist as to what occurrences would or
would not despoil the visual beauty of an area, and applicants should be
sensitive to these commonly held aesthetic conventions. Applicants
should contact the Federal land manager for the determination of scenic
vistas for Class I areas and for construction projects subject to the
PSD regulations if emissions may be expected to impact any Class I area.
The completion-of the visibility analysis marks the completion of the
additional impacts analysis.
D.2.4 Summary
In preparing an additional impacts analysis, the applicant should
realize that a primary intent of the analysis is to provide environ-
mental impact-information to the public regarding the air quality-related
impairments o.f soils, vegetation, and visibility produced by the source
or modification under review, and the associated growth that it generates.
To convey this information in a comprehensive manner, the additional
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impacts analysis contains three component analyses that are related to
each other in an inforroationally progressive manner. Also, the results
of the additional impacts analysis will help define BACT for affected^
emissions units. The growth analysis leads to the soils and vegetation
analysis, which in turn leads to the visibility analysis. All these
analyses are concerned with the air quality-related impacts on an area,
and the analyses should be fully documented. Hopefully, by using the
suggested approach in this chapter, the applicant will become aware that
what is under review is a unique set of circumstances particular to the
source or modification and its surrounding area.
If the additional impacts analysis is approached in a conscientious
manner, the applicant not only will have met the requirements of the PSD
process, but will also have provided an analysis that can serve as a
platform from which industry, the public, and the appropriate regulatory
agencies can broaden their understanding of matters of local environmental
concern.
D.3 ADDITIONAL IMPACTS ANALYSIS EXAMPLE
Sections D~. 1 and D.2 outlined, in general terms, the elements and
considerations found in a successful additional impacts analysis. To
demonstrate how this analytic process would be applied to a specific
situation, a hypothetical but realistic case has been developed for s.
minemouth power plant. This section will show how an additional impacts
analysis would be performed on that facility.
D.3.1 Example: Background Information
The minemouth power plant consists of a main body power plant and
an adjoining lignite mine, which serves as the plant's source of fuel.
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The plant is capable of generating 1,200 megawatts, which is expected to
supply a utility grid, and little is expected to be consumed locally.
This project is located in a sparsely populated agricultural area in the
southwestern United States. The population center closest to the plant
is the town of Clarksville, population 2,500, which is located 20 kilo-
meters from the plant site. The next significantly larger town is
Milton, which is 130 kilometers away and has a population of 20,000.
The nearest Class I area is more than 200 kilometers away from the
proposed construction. Within the area under consideration there are no
National or State forests, no areas which can be described as scenic
vistas, and no points of special historical interest.
The company engineers and contractors have estimated that the
construction of the power plant and the development of the mine would
require an average work force of 450 people over a period of 36 months.
Upon completion of all construction, it is.expected that about 150
workers will be needed to operate the facilities.
To perform an additional impacts analysis of this project, an
applicant begins a growth analysis by acquiring a projection of growth
that would be associated with the construction and operation of the
project. Following are some of the local support factors the applicant
considers.
D.3.1.1 Work Force. Consulting the State employment office, local
contractors, trade union officers, and other labor information sources,
the applicant made the following estimates regarding worker availability.
Of the 450 construction jobs available, most will be filled by
workers commuting various distances to the construction sites, with some
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workers coming from as far away as Milton. The applicant expects that
some workers and their families can be expected to move to Clarksville
for the duration of the construction. Of the permanent jobs, an estimated
100 will be filled by local workers. The remaining 50 permanent positions
will be filled by nonlocal employees, because these jobs require a
degree of skill, training, experience, or education that is not found in
the area's existing work force. These workers and their families are
expected to relocate primarily in the vicinity of Clarksville.
D.3.1.2 Housing. In contacts with local governmental housing
authorities and realtors, and by scanning the classified advertisement
sections of the local newspaper, the applicant learned that the predomi-
nant housing unit in the area is a single family house or mobile home.
The applicant also learned that the easy availability of mobile homes,
mobile home lots, and residential land provides a local capacity for
quick housing expansion.
An examination of these local support factors led the applicant to
conclude that there will be no substantial air quality-related impacts
associated with residential growth. Although there will be some emissions
associated w-rth the construction of new homes, these emissions will be
temporary, lasting only as long as the construction schedule. Because
of the limited number of housing units expected to be constructed, these
emissions are considered insignificant. The small number of new people
brought into the community through employment at the plant is not expected
to generate commercial growth. For example, the community will not need
an increase in small industries that support the power plant (i.e.,
small foundries or rock crushing operations).
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D.3.1.3 Industry. Because of the relatively self-contained nature
of minemouth plant operations, no related industrial growth is expected
to accompany the operation of the plant. Emergency and full maintenance
capacity is contained within the power-generating station. With no
associated growth projected, it then follows that there will be no
growth-related air pollution impacts.
D.3.1.4 Soils and Vegetation. In preparing a soils and vegetation
analysis, the applicant has acquired a listing of the soil and vegetation
types native to the impact area. The vegetation is dominated by pine
trees and hardwoods consisting of loblolly pine, blackjack oak, southern
red oak, and sweet gum. Smaller vegetation consists of sweetbay and
holly. Small farms are found west of the forested area. The principal
commercial crops grown in the area are soybeans, corn, okra, and peas.
The soils range in texture from loamy sands to sandy clays. The principal
soil is sandy loam consisting of 50 percent sand, 15 percent silt, and
35 percent clay.
The applicant, through research, determined the sensitivity of the
various soils and vegetation types to each of the applicable pollutants
that will be emitted by the facility in significant amounts. The applicant
then correlated this information with the estimates of pollutant ambient
air concentrations which were calculated previously in the NAAQS analysis.
Because the noncriteria pollutant emission rates already have been
demonstrated in the applicability example of this case to be insigni-
ficant, the soils, vegetation, and visibility impacts are concerned only
with applicable criteria pollutants.
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According to the correlation results between the predicted ambient
air concentrations and potential soils and vegetation impacts in the
impact area, only soybeans prove to be potentially sensitive. A more
careful examination of soybeans reveals that no adverse effects were
expected at the low concentrations of pollutants predicted by the
modeling analysis. Major sulfur dioxide (S02) impacts on soybeans have
been demonstrated at greater than 0.1 ppm for a 24 hour period. This S02
ambient air concentration is greater than that predicted by the modeling
analysis to result from the proposed emissions.
Fugitive emissions emitted from the mine and from coal pile storage
will descend upon both the soil and leaves of vegetation in the immediate
area of the plant and mine. Minor leaf necrosis and lower photosynthetic
activity is expected, and over a period of time the vegetation's community
structure may change. However, this impact occurs in an extremely
limited area very near the emissions site and, in addition, rain fall
can mitigate this effect. For these reasons, the impact is considered
insignificant.
Limestone preparation and storage also must be considered for
potential impacts. High relative humidity may produce a crusting effect
of the fugitive limestone emissions on nearby vegetation; however, this
impact is limited and only occurs very near the power plant site. For
this reason and because of the mitigating effect of rain, this impact is
considered insignificant. Additionally, BACT on the limestone storage
piles will minimize the emissions.
D.3.1.5 Visibility Analysis. With the soils and vegetation analysis
completed, the applicant performed a visibility analysis. The applicant
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performed a screening procedure similar to that outlined in the draft
EPA document "Workbook for Estimating Visibility Impairment." The
screening procedure is divided into three levels. Each level represents
a screening technique for an increasing possibility of visibility impairment.
The applicant executed a Level 1 analysis which involved a series of
conservative tests that permitted the analyst to eliminate sources
having little potential for adverse or significant visibility impairment.
The applicant performed these calculations for various distances from
the power plant. In all cases, the results of the calculations were
numerically below the standardized screening criteria. Therefore, the
applicant concluded that the Level 2 and Level 3 analyses were unnecessary
and that no visibility impairments were expected to occur within the
source area.
In preparing the suggested visual and aesthetic description of the
area under review, the applicant noted the absence of scenic vistas.
Thus with the visibility analysis completed, the applicant has performed
all the component analyses of additional impacts.
D.3.2 Example: Additional Impacts Conclusions
After completing the visibility analysis, the applicant completed
the additional impacts analysis. To aid in its review, the applicant
documented every element of the analysis. Because a primary intention
of the PSD permit process is to generate public information regarding
pollutant impacts, the applicant prepared the report in straightforward
and concise language.
The demonstration of an additional impacts analysis of a hypothetical
minemouth power plant is realistic. Although, in this example, just
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the highlights of the analysis are presented, an actual analysis may
contain more detailed considerations, and other types of facilities
under review may produce more growth and more or different kinds of
impacts. For example, the construction of a large manufacturing plant
could easily generate air quality-related growth impacts, such as a
large influx of new workers to an area and the growth of associated
industries. In addition, the existence of particularly sensitive forms
of vegetation, the presence of Class I areas, the presence of particular
meteorological conditions, and the existence of scenic vistas or historical
sites in the area would produce an analysis which would be of necessity
greater in scope.
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PART II: APPLICATION REVIEW
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A. APPLICABILITY
It is the responsibility of the review authority to carry out the
requirements of the prevention-of-significant-deterioration (PSD) regula-
tions. The broad goal of PSD is to prevent significant air quality
deterioration in clean air areas and, at the same time, also provide a
margin for future industrial growth.
The present PSD regulations (40 CFR 52.21) provide minimum standards
for maintaining air quality increment until each state adopts the PSD
program into its State implementation plan (SIP). Within guidelines,
each State will tailor these PSD regulations to meet the specific needs
of its area. Once State PSD regulations are incorporated into the
existing SIP and have been approved, the States will have a more efficient
regional air quality management tool that balances air quality resources
with local needs for continued industrial growth. From that point on,
PSD review will follow the guidelines and regulations described in each
particular State implementation plan.
In the PSD review process the applicant is responsible for
(1) performing all required analyses, (2) documenting the results in a
clear and concise form in the permit application, (3) applying best
available control technology (BACT) where required, and (4) maintaining
compliance with all permit conditions.
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The role of the review agency is to evaluate the preconstruction
analysis performed by the applicant for compliance with statutory require-
ments, and to manage regional air quality through a collective assessment
of industrial growth. By following these procedures, the reviewing
authority meets its responsibility through the preconstruction permitting
process. Because PSD regulations place the burden of analysis on the
applicant, the engineering analysis provided must show that air quality
standards and available increment will not be threatened and that BACT
is applied. A thorough evaluation by the review agency of the analyses
presented in the application is instrumental in maintaining the
opportunity for future industrial growth in a particular area.
The permitting authority is not expected to redo an incomplete or
unsatisfactory application. Analysis and thorough documentation is the
responsibility of the applicant. When an incomplete application is
submitted, or'when the analyses presented do not adequately demonstrate
compliance with PSD requirements, the applicant should be notified and
required to correct any deficiencies.
This section of the guidance package suggests the logical steps
needed to complete a thorough review of a proposed source's applicability
under 40 CFR 52.21. Also, common oversights and errors made by the
applicant will be examined. In addition, this section also includes
methods the review agency can follow to reduce mistakes and minimize the
review agency's manpower requirements.
A.I PERMITTING PROCESS STEPS
The major steps in implementing the permit process are:
the preapplication meeting,
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completeness review,
preliminary determination,
the opportunity for public review and comment, and
t the final determination with corresponding compliance checks.
During the preapplication meeting, the review agency should make a
preliminary assessment of applicability which determines whether or not
PSD review is necessary and what PSD review requirements must be met.
An assessment of applicability, at this time, outlines the engineering
analyses which must be performed, and is of prime concern to the source
proposing construction. Also, PSD applicability assessment is the
starting point of the review for completeness of a submitted application.
The review agency is responsible for both the application review
and the development of the preliminary determination. The preliminary
determination has a dual purpose: (1) it provides a comprehensive air
quality-related environmental assessment of the key impacts from a
proposed expansion, and (2) it provides the general public with a
description of the project's impacts, requirements, and compliance
demonstration. A suggested format for preliminary determinations is
included in Appendix 1.
The last step in the review process is the publication of a public
notice and a request for public comment on the preliminary determination.
After the public comment period or public hearings are closed, and
following an evaluation of public comments, the review agency must
complete the process by making a final determination of approval, approval
with conditions, or disapproval. The methods for compliance checks must
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be included with the final determination. Before a final determination
is made, public comments should be made available to the applicant for
the opportunity to provide responses to the PSD review agency.
A.2 EVALUATION OF APPLICABILITY
The determination of applicability is the focal point of the
preapplication meeting and the completeness review, and also is crucial
in determining which analyses must be performed. Therefore, it is
critical that correct determinations be made as early as possible in the
planning of a construction project. Incorrect or incomplete determi-
nations can cause serious construction delays and add considerably to
agency resource requirements through superfluous or redundant evaluations.
This section, therefore, outlines the five steps necessary to fully
evaluate applicability.
A.2.1 Identification of Source and Proposed Construction
The first step is to identify the source and understand the proposed
construction.. Has the applicant correctly defined the proposed new or
existing source according to PSD definitions? For a modification to an
existing source, has the applicant fully described the physical change
or change in the method of operation of the source, and has he or she
identified all additional new and modified emissions units? One helpful
suggestion for a reviewer attempting to verify an applicant's work is to
list the emissions units proposed for construction. For modifications, a
listing of new and modified emissions units and emissions units involved
in any associated contemporaneous changes is useful. Also, listing all
existing emissions units can help define the existing source. Frequently,
a PSD applicant may be unaware that there are more emissions units at
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his or her source than he or she anticipated. For instance, cooling towers
are often ignored as a source of fugitive hydrocarbon (HC) emissions. For a
general understanding of a process or source type which is new to a
review engineer, consult AP-40 and AP-42. These publications will aid
the reviewer's understanding of the proposed project.
A.2.2 Examination of Emissions Estimates
The next major step in applicability review is to check the applicant's
emissions estimates. Any discrepancies in the emissions estimates, which
are not identified and corrected, may result in an incorrect applicability
determination-. The keys for evaluating the emission estimates follow:
1. Make- sure that every regulated pollutant which the source will
emit is listed, and that each affected emissions unit is evaluated.
2. Check the basis for the potential to emit (PE) and for actual
emissions estimates. Do all assumptions conform with the PSD definitions?
Are they reasonable or conservative in an engineering sense? Did the
applicant use less than maximum capacity for these estimates without
demonstrating, the existence of enforceable restrictions?
3. Determine if the applicant presented the accumulated increases
and decreases for all emission units located at the source. Were the
quantifiable fugitive emissions included where necessary? Will the
described modification affect emissions units which are not discussed?
4. Remember that all claimed emissions changes must be
contemporaneous and creditable. Refer to Section A.4.3.2 of the application
guidance package, and the PSD regulations' definition of "net emissions
4
increases" for assistance.
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5. Finally, the reviewer must verify that the applicant's estimates
of potential emissions and the "net change" in actual emissions are
reasonable and consistent with definitions given in the PSD regulations.
Guidance on these definitions is offered in Sections A.3 and A.4.3.2 of
the application guidance package as well.
A.2.3 Examination of Location
The third major step in applicability review is to evaluate the
location of the proposed construction. Has the applicant considered all
Class I areas which are in that locale? Is the proposed construction
site in or near a nonattainment area for any pollutant or an area of
known increment violation for particulate matter (PM) or sulfur
dioxide (S02)?
A.2.4 Applicability Tests
The fourth step is to perform the applicability tests outlined in
the application guidance package. Has the applicant correctly applied
these tests, to determine if the proposed source is subject to PSD
review, and what requirements must be met?
A.2.5 Exemptions
The final step in determining applicability is to examine any
exemptions claimed by the applicant. In many cases, exemptions are
conditioned on the construction affecting no Class I areas, no
nonattainment areas, and no known areas of increment violations.
A.3 COMMON OVERSIGHTS AND ERRORS
For those reviewers who are just, beginning their work with PSD,
there are several areas where applicants and reviewing authorities tend
to make errors. These areas deserve particular attention.
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A.3.1 Source Def1niti on
Source definition can be a problem in an application. Sometimes
the applicant will incorrectly define the source. For example, the
applicant may consider only the new and modified emission units as the
source. Although this is consistent with many State plans, it is incon-
sistent with the 1980 PSD regulations. The present definition includes
all existing emissions units at a location which are associated under
the same two-digit SIC code. Source definitions for preconstruction
review under nonattainment provisions are not identical to PSD source
definitions. Refer to the PSD regulations and Section A.2 of the
application guidance package for a complete definition and guidance
on correctly defining the source.
More subtle mistakes in source definition occur at large complexes
which are proposing additions to the existing source. For these sources,
the review agency should check files for previous source determinations
conducted at the same location and for determinations on similar sources.
Contacting local enforcement personnel to verify existing emissions
units and to gain an understanding of the source is generally very
helpful.
A.3.2 Emi s s i ons Es ti mates
Other mistakes in a PSD application occur in the emissions estimates.
Both the PE and actual emissions estimates may be incomplete. For
example, emissions units that should be included may be overlooked or
ignored and pollutants regulated under the Clean Air Act may be excluded
from the list of emissions estimates. Again, this is generally a defini-
tion problem. Also, pollutants may be missing from the emissions estimates
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because the applicant is unaware that PSD review applies to all pollutants
regulated under the Act. Some applicants concentrate on S02 and PM, the
pollutants for which increments have been established. Another common
oversight is to concentrate on the criteria pollutants and to forget to
present emissions estimates for the noncriteria pollutants regulated by
the Act.
A similar problem occurs with emissions estimates for equipment
types with a dominant pollutant. Examples are rock dryers, grain dryers,
and asphalt plants that emit large quantities of particulate. Some
applicants will focus on these emissions and overlook the emissions from
combustion products released through fuel consumption to provide process
heat. Nitrogen oxides (NO ), carbon monoxide (CO), S02, hydrocarbons (HC),
and all other regulated pollutant emissions must be estimated.
The experience of the reviewer is important in detecting these
oversights, but an overall awareness of common problems in PSD analyses
is also helpful. In addition, a pollutant checklist similar to Figure A-l
will aid in correcting these errors.
A.3.2.1 Fugitive Emissions. When checking an applicant's emissions
estimates, the reviewer may find that estimates for fugitive emissions
are absent. Quantifiable fugitive emissions estimates must be presented
if they are expected to occur. However, a source may be eligible for an
exemption if it would be designated a major source because of its fugitive
emissions. This exemption applies only to sources other than the 28 named
source categories and sources regulated under Sections 111 or 112 of the Act.
Quantifiable fugitive emissions are considered in all other emissions estimates,
including calculations of actual emissions and net changes in actual
emissions, to determine the level of PSD review required.
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SIGNIFICANT
CHECK POLLUTANT NET INCREASE*
C] Carbon monoxide TOO tpy
O Nitrogen oxides 40 tpy
D Sulfur dioxide 40 tpy
D Particulate matter 25 tpy
Q Ozone (volatile organic compounds) 40 tpy
D Lead 0.6 tpy
Q Asbestos 0.007 tpy
D Beryllium 0.0004 tpy
Q Mercury 0.1 tpy
Q Vinyl chloride 1 tpy
Q Fluorides 3 tpy
C3 Sulfuric acid mist 7 tpy
Q Hydrogen sulfide 10 tpy
Q Total reduced sulfur 10 toy
(including H^S)
C Reduced sulfur compounds 10 tpy
(including HS)
Tons per year.
Figure A-l. Checklist for pollutants regulated under the
Clean Air Act.
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A.3.2.2 Emission Factors. Another common mistake made by an
applicant in determining both potential emissions and actual emissions
is the use of inappropriate emission factors. The reviewer can make
checks by consulting the emission estimates of other applications or by
examining BACT/LAER Clearinghouse reports for similar source types.
Identifying mistakes caused by overestimation of emissions can reduce
review requirements and, in some cases, can eliminate a source from PSD
review. In contrast, reviewers should also closely scrutinize estimates,
and the basis for estimates, in cases in which the total source emissions
fall just below the 100/250 ton criterion and in cases in which the net
increase in actual emissions falls just below the defined significance level
A.3.2.3 Potential and Actual Emissions Definitions. Finally,
potential emissions and actual emissions definitions are sometimes
misunderstood. The reviewer can check these definitions in the PSD
regulations or the application guidance package. When an incorrect
definition is used, an extensive revision to emissions estimates is
commonly required.
Another emissions estimating error is pertinent only to potential
emissions. Estimates for potential emissions are often based on average
rather than maximum capacity operation. The only time maximum capacity
operation should not be used in potential emissions estimates is if
there are enforceable restrictions on a source's ability to emit a
pollutant. Where restrictions are claimed by an applicant, they must be
federally enforceable.
A.3.2.4 Net Emissions Changes. There are two common mistakes made
in estimating the net change in actual emissions. First, the applicant
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may "fail to accumulate all the creditable contemporaneous increases
which have occurred at the source in the previous Sryear period. In
addition, decreases that do not meet the criterion of contemporaneous
may be claimed by the applicant. Decreases that are not federally
enforceable cannot be credited in determining the net emissions change.
Refer to the PSD regulations and Section A.4.3.2 of the application
guidance package for special guidance on crediting contemporaneous
emissions changes.
The second problem is the misinterpretation of actual operating
data. Sometimes the assumptions used in calculating actual emissions
are not indicative of actual operating records. The application should
fully document the operating data on which actual emissions estimates
are based. As a check, the reviewer should consult State emissions
inventory questionnaires. A questionnaire response for that particular
plant site or a similar plant type made on the basis of actual operating
data may be available.
A.4 RECOMMENDATIONS
A.4.1 Preapplication Meeting
Although there are many common pitfalls in the PSD application
process, the reviewer can help the applicant avoid many of the obvious
problems. The preapplication meeting is the best time to communicate
this type of information to the applicant.
After the reviewer has examined the applicant's general proposal, a
preliminary assessment of applicability often can be made. Based on
this assessment, the reviewer should be able to focus the applicant's
attention on the likely review requirements. Sensitive issues, particular
to the area of the proposed construction site, should be pointed out to
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the applicant. Moreover, the reviewer should Indicate to the applicant
the definitions and the regional policy on review requirements.
Baseline dates for each pollutant with an established baseline date
and information on increment consuming sources also can be supplied at
the preapplication meeting. A copy of the application guidance package
tailored to meet a specific area's needs should be provided for the
applicant at this meeting.
A.4.2 Completeness Review
During the time period allocated for the completeness review, the
reviewer must determine if sufficient information has been supplied. A
data summary sheet (Appendix 2) will help the reviewer make this assessment.
Once an application is determined to be complete, the agency has a maximum
time-period to complete the PSD review. Because the application is restricted
by a time schedule, the applicant has less incentive to supply additional
information. Also, a considerable amount of time is often required to develop
the additional'information. Thus the applicant should be made aware of additional
information requirements at the earliest possible date.
The date that a complete application is received generally determines
permitting prtority. Mistakenly identifying an application as complete
may be unfair to another source in the same area.
Additional" information sometimes necessitates a revaluation of
previously reviewed analyses, which is redundant and cost-inefficient.
Therefore, emphasis on a thorough completeness review can expedite the
overall PSD review process, minimize any effects on construction schedules,
reduce agency resource expenditures, and aid the proper management of
air quality resources.
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A. 5 CONCLUSION
In conclusion, the PSD application is an engineering analysis
performed by the applicant. The applicant must document all assumptions
made. In fact, the application stands as part of the public record.
The review agency should make every effort to verify the information
presented in the application, especially in the areas specified as
problem areas. The PSD data summary sheets will help the reviewer
complete this task (Appendix 2).
Each application will need to be examined for its own peculiarities,
but when the reviewer carries out his or her job properly, the PSD
program will serve as an effective air quality management tool, tailored
to the needs of each individual State or air quality region.
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B. BEST AVAILABLE CONTROL TECHNOLOGY
An applicant proposes best available control technology (BACT)
emissions limitation for each applicable pollutant emitted from each new
based on supporting evidence and documentation derived from a thorough
analysis. The reviewer uses the analysis submitted by the applicant to
establish the PSD permit conditions that will specify the operation of
the control strategy for the source or modification under review.
To fully assess an applicant's BACT analysis, the reviewer must not
only possess a broad knowledge of the information and situations referred
to in the analysis, but also must be aware of the PSD requirements for
the BACT analysis and the methods suggested for meeting these requirements.
It must be stressed that a BACT analysis is a case-by-case assessment
generally limited in scope to the effects and operation of the source or
modification under review. A BACT determination is dependent on the specific
nature of the factors for that particular case. The depth of a BACT analysis
should be based on the quantity and type of pollutants emitted and the degree
of the resulting expected air quality impacts.
The purpose of a BACT analysis is to determine the lowest emissions
that can be met by a source or modification, in light of economic,
environmental, and energy impacts. The BACT analysis begins with an
evaluation of emissions control options and ends with a proposed continuous
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or modified emission source subject to BACT. In assessing the BACT
analysis, the reviewer may require a more stringent emission rate than
that proposed by the applicant, providing that the reviewer's decision
is based on factual information. Should the reviewer disagree with the
proposed BACT, his or her reasons and justification should be made known
to the applicant before continuing with the review. In these cases,
informal meetings and negotiations may help resolve disagreements.
B.I BACT ANALYSIS REVIEW
The reviewer's primary responsibility is to determine the best
emissions strategy to balance the environmental benefits gained from
applying pollution control technology with the prudent use of energy and
justifiable industrial expenditures. To achieve this goal, the reviewer
brings the following questions to bear on the BACT analysis under
consideration:.
t Is the analysis complete? The analysis must be pollutant-
and emissions unit-specific because each affected new or
modified emissions unit must be evaluated with respect to
each pollutant subject to PSD review. Major emissions sources
should be emphasized; however, the requirement for enforceable
continuous limits remains, even for relatively minor emissions
units. In general, the attention of the analysis should be focused
where it can produce the most environmental benefits.
Is the analysis thorough? Has the applicant evaluated
the range of demonstrated options, including alternatives,
that may be transferable or innovative? The applicant
need not evaluate control alternatives that would result
in greater emissions than those proposed as BACT. For
example, in a sanding operation, the control options
would be a cyclone collector, a baghouse, and an electro-
static precipitator. If the applicant had proposed a
baghouse as BACT, a detailed analysis of the cyclone
would generally be unnecessary.
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Are the cost estimates which appear in the analysis
reasonable? Do they appear to contradict cost
expectations and experience?
Has the applicant made a good faith effort proposing
BACT?
These questions will help identify those elements of a BACT analysis
that may be incorrect or incomplete. This review approach places the
burden of thorough documentation on the applicant.
Although the applicant is expected to provide the appropriate data
to support conclusions, in those areas where the reviewer lacks extensive
knowledge, he or she is encouraged to use the information contained
in BACT/LAER Clearinghouse reports, literature references, national
emission standards, and other EPA literature. Even after a PSD applica-
tion is considered complete, the reviewer can still request additional
information from the applicant to clarify the data and facilitate
the BACT decision.
The reviewer should pay particular attention to the applicant's
engineering analysis. The level of detail in the control options analysis
should vary with the relative magnitude of the emissions reduction
achievable. The reviewer may question information submitted by the
applicant; however, he or she should not develop cost estimates for the
applicant.
Where it is evident that the applicant has conducted a good faith
engineering effort, the reviewer can proceed in the assessment of the
analysis by examining the proposed BACT emissions limits. These limits
can be considered the bottom line of the analysis. If the rest of the
analysis appears satisfactory upon examination, the reviewer's resources
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are best utilized by concentrating on the area of emissions. If the
applicant is proposing a control strategy that will produce the lowest
emission rate of all alternatives, no further analysis is required.
However, if it is apparent that the applicant has conducted an insuffi-
cient engineering analysis, it is the reviewer's responsibility to
evaluate the design of the control system under review to ensure that
the proposed technology is capable of achieving the proposed emissions
limits. In those cases in which inadequacy is noted, the applicant should
be questioned regarding these points.
B.2 CONCLUSIONS
BACT must be a system of continuous emission reduction. The applicant
will suggest the control technology, but ultimately the reviewer.is responsible
for establishing the permit conditions that specify the operation of the control
systems. Therefore, permitted emission rates must be specified on the basis of
both total and specific allowable emissions. The total allowable emission rate
(pounds per hour) of a unit is the anticipated emission rate when the unit is
operating at its maximum capacity. However, because BACT is a system of
continuous emission reduction, the allowable emissions must also consider the
required control strategy at all other operating levels. This task is
generally done by specifying, wherever possible, the allowable emissions
in terms of process unit variables such as material processed or fuel
consumed, or even by specifying an allowable pollutant concentration in
stack, gases. Allowable emissions such as pounds per million Btu or
pounds per ton-of product serve this purpose. However, no BACT can be
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any less stringent than any applicable new source performance standard (NSPS),
national emission standard for hazardous air pollutants (NESHAP), or
other SIP limitations. Therefore, the reviewer must check to see that
the total system proposed by the applicant and the permit conditions are
enforceable.
It is the reviewer's responsibility to specify enforceable equipment
or work practice standards in those situations in which emissions are
expected but are not measureable. An example of a system of enforcement
might be recordkeeping regarding the emissions unit, in a situation in
which a maintenance and monitoring program were the BACT for leaking valves
in a petroleum refinery. The recordkeeping would serve to determine the success
of the specified program.
To make BACT enforceable and continuous, the reviewer should
realistically consider the reliability of the control systems. For
example, the reviewer should consider the average efficiency and not the
maximum efficiency of a control, and should devise compliance and monitoring
systems that are repeatable and straightforward, if necessary.
Reviewers should also note that some applicants might be motivated
to propose allowable emissions, that, in the opinion of the reviewer,
are excessive. It is inefficient to try to squeeze the last ounce of
allowable emissions from a proposed allowable emission rate. However,
one of the prime objectives of PSD is to require emission control strate-
gies that force the evolution of pollution control technology. Industrial
motivation to force this technology will be reduced if allowable emissions
can easily be met with a large margin of safety.
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C. AIR QUALITY ANALYSIS
The agency responsible for reviewing the PSD permit applications
must undertake a careful analysis of the data presented. The applicant
is required to analyze the air quality impact of the proposed source or
modification and present data to substantiate all analyses. The analyses
must be complete and accurate and ensure compliance with the national
ambient air quality standards and PSD increments.
C.I AIR QUALITY AND MODELING APPLICATION REVIEW
The application presented for review must adequately address all
relevant elements of PSD to be considered complete. Each element presented
in the application must be carefully reviewed. The steps in this review
include:
A determination and quantification of those pollutants
for which air quality review is required,
A clear description of the proposed source or modification,
A review of modeling techniques,
A determination of existing air quality,
A check for impact on Class I areas, and
A comparison of analyses results with the national ambient
air quality standards and allowable increments.
C.I.1 Pollutants Requiring Review
All regulated pollutants that may be emitted in significant quantities
from the proposed source or modification are subject to the air quality
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review. The pollutants that must be part of the air quality review are
generally identified in the applicability analysis, which determines if
the proposed construction is subject to review and what analyses must be
performed if a PSD permit is to be issued.
C.I.2 Description of the Source
The modeling analysis presented for the proposed source or modification
must be reviewed for completeness and accuracy. However, before modeling'
analyses are reviewed, a thorough understanding of the project must be
developed.
The model presented by the applicant is a mathematical respresentation
of a physical situation. A clear picture of the physical setting of the
proposed source is a prerequisite to properly reviewing the mathematical
representation. Such an understanding should encompass all facets of
the proposed source or modification. A description of all emissions
units including allowable emissions, stack parameters, location, and
nearby tall buildings is required. The review must also ensure the
inclusion of all sources of fugitive emissions in the proposed project.
If the project is a modification, then changes in actual emissions
at the source.-must be established. The review agency should carefully
examine all changes in actual emissions. These must be carefully documented.
A review of whether the changes are reasonable and in agreement with
State files is 5 good check.
A plot plarr can be useful in determining emissions unit location
and possible critical meteorology. The plot plan will assist the reviewer
in the analysis of source interaction and building downwash effects. In
many cases, the applicant will make what he or she considers conservative
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assumptions in performing dispersion modeling. The plot plan is helpful
in determining if these assumptions are indeed conservative.
C.I.3 Modeling Techniques
If a modeling plan has been submitted by the applicant, a quick
check will provide the review engineer with the information necessary to
determine if the applicant has completed his or her intentions. The
review engineer should compare the procedures outlined in the PSD appli-
cation with those in the modeling plan. This is especially important in
cases in which the modeling plan has been approved with conditions and
stipulations.
The modeling data presented by the applicant in his or her application
should be complete-and accurate. The reviewer should:
Determine which models were used,
Ensure that all sources are included in the inventory,
Examine allowable and actual emissions for proper treatment,
Check meteorological data used,
Review modeling assumptions used, and
Check good engineering practice (GEP) stack height regulations
with respect to the operation.
C.I.3.1 Model Selection. All models used by the applicant must be
examined by the reviewing agency. Acceptable models and procedures are
those found in the latest revision of EPA's Guideline on Air Quality Models
and the Air Quality Maintenance Planning and Analysis Guidelines, Volume 10.
In selecting a model, it is the applicant's responsibility to
submit for review any modifications made to the guideline models. These
modifications include any changes to the theory or computer code that
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may alter the results. Each modification requires review agency approval.
A model should only be used in those applications for which it was
designed. For example, the CRSTER model should be used for single-source
rural modeling. However, a different model should be selected for
multiple-source situations.
Approval for use of alternative models (i.e., models other than
those specified in the Guideline on Air Quality Models) is given only if
acceptable technical justification is presented. The alternative model
must be sufficiently documented so the reviewer can understand the
difference between alternative and recommended models. In addition, a
comparative analysis between an alternative model and a recommended
model must be presented. Guidelines for performing such a comparison
are presented in the Guideline on Air Quality Models. This type of
analysis should include several runs of each model that highlight the
technical differences between the models. An applicant should be
encouraged to discuss model selection with the review agency before
performing the analysis.
An important element of model selection is land use within 3 kilometers
of the .source. Whether this area is rural or urban is a factor in
determining what model is most appropriate for a given situation. The
Guideline on Air Quality Models suggests methods for determining the
land use of a given area.
C.I.3.2 Inventory. It is the responsibility of the applicant to
establish an inventory for all sources of emissions within the impact
area, as well as for large major sources within 50 kilometers of the
impact area that may cause significant impacts in the impact area. The
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complete inventory consists of increment-consuming emissions and emissions
that are not included in the estimate of existing air quality. Addi-
tionally, the applicant should use the appropriate emissions inventory
to demonstrate that ambient air monitors were properly located.
The data presented by the applicant should make use of State and
Federal air permit files. The review authority should perform checks on
these inventories. State agency permit files or previous PSD permit
applications in the area can be used for this purpose. The objective is
to determine that all significant sources and all increment-consuming
emissions are considered.
A critical element in establishing the increment inventory is the
baseline date. This is the date after August 7, 1977 on which the first
complete PSD application subject to the new regulations is submitted.
The baseline date is pollutant-specific; therefore, a source that is not
subject to PSD review for sulfur dioxide (S02) but that is subject for
particulate matter (PM) may set the baseline date for PM but not for
S02.
The reviewing authority should check that the baseline date is
correctly established for all areas that contain sources whose emissions
may affect increment consumption in the proposed source's impact area.
Baseline date is important to the increment analysis because, after that
date, all changes in emissions at both major and nonmajor sources will
consume or expand increment. Thus, for new and existing sources for S02
or PM, changes in emissions resulting from construction commencing after
January 6, 1975 consume or expand increment. This type of check can be
conducted by the following steps:
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1. Determine all Section 107 areas where the source will have a
significant impact.
2. Establish nearby Section 107 areas within 50 kilometers of the
proposed source's impact area, and then check for the date of the first
complete PSD application submitted after August 7, 1977 in each area.
It is recommended that each review authority conduct an analysis
for baseline dates as soon as possible so that confusion is avoided
during the review of future applications. This is especially important
for areas in and around heavily industrialized areas where PSD activity
is expected to be substantial.
C.I.3.2 Documentation of Actual Emissions. In certain areas of
the country,, many increment sources are permitted to emit more pollutants,
such as S02 than they regularly emit. In many cases, an applicant will
use allowable emissions as a conservative estimate of actual emissions
for the purpose of increment consumption analysis. If, however, he or
she chooses to use actual emissions, the data must be adequately docu-
mented and verified. A review of the State air pollution control agency
files may provide data on actual emissions. In the absence of substantive
data in State files, plant authorities should be consulted for information
about their actual emissions. If no data are available regarding actual
emissions, then allowable emissions must be used.
After checking the applicant's source inventory against State
records, a plot of all major sources should be prepared. The plot will
reveal the lines of source interaction for the reviewer. In most cases,
use of guideline models and techniques will produce results that predict
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maximum ambient concentrations in an area. The review engineer should
check the results against the plot and against his or her own knowledge
of meteorology and air quality in the area. The reviewer then must
decide if the results are reasonable and whether they are consistent
with results from other recent analyses in the area. The reviewing
engineer should be convinced by the application data that there are no
possible unconsidered situations that would lead to higher concentrations.
C.I.3.4 Meteorology. Meteorological data presented by the applicant
for review must be typical of the area in question and may be gathered
from sources in accordance with procedures in the Guideline on Air Quality
Models. The applicant may gather data from the National Climatic Center
in Asheville, North Carolina, which supplies hourly observations for
many areas of the country. The applicant may alternatively secure data
from an onsite monitoring program. The EPA regional meteorologist or
reviewing authority meteorologist should be consulted regarding the use
of meteorological data.
Site-specific arguments may be presented by the applicant. For
example, the applicant may contend that winds along a given line of
source interaction are uncommon in the region and that they cannot
persist long enough to cause high concentrations. These arguments must
be carefully scrutinized by the reviewer. A review of the meteorology
should confirm such contentions.
C.I.3.5 Review Modeling Techniques. Several items need to be
considered when reviewing the modeling analysis, including receptor
locations, model inputs, and modeling assumptions. The correct placement
of receptors is critical to the determination of maximum impact. The
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reviewer should check the placement of receptors against source locations
on the impact area source plot and critical meteorology. This review
will ensure that maximum impact is presented by the applicant. Misplace-
ment of receptors can cause low concentrations to be predicted with
otherwise critical meteorology. To determine the correct placement of
receptors, the reviewer must carefully analyze the wind direction and
source interaction lines. Any questions concerning receptor placement
or any other modeling question should be directed to the EPA modeling
contact or designated representative.
Once the receptors are placed and maximum concentrations are predicted
by the applicant, then the receptor grid density around the maximum
receptor should be increased to a 100-meter spacing to establish that
the highest maximum has been found. -If the initial modeling was completed
using 1-kilometer spacing, then it is entirely possible that, with an
increase in grid density, the concentration estimate may increase
considerably.
Once a specific model has been chosen, the model must be applied
properly. It is the responsibility of the reviewer to determine that
the model has been applied properly and that the applicant has used the
model correctly. An appropriate model for a given application can be
incorrectly applied and thus produce erroneous results. Generally, a
review of the input options will reveal any erroneous assumptions that
were made for the model run. Approved models should be run with recom-
mended options unless these options are inappropriate for an application.
In this case, the reviewer must approve any alternative options. These
options should be carefully evaluated with respect to the particular
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model application. Any deviation from modeling using the maximum allowable
emission rate should be noted. This deviation may require an enforceable
permit condition to restrict source operation at these rates. In some
cases, however, a source may cause a higher ambient impact when operating
at less than peak load. An analysis compatible with the Guideline on Air
Quality Models should be performed by the applicant to ensure that
sources are modeled to predict maximum ground-level concentrations.
C.I.3.6 Good Engineering Practice (GEP). A review of tall buildings
near the proposed emission points that considers all possible downwash
effects must be conducted. The good engineering practice (GEP) stack
height regulations and their accompanying technical support document
provide guidance on identifying potential downwash problems. The appli-
cant should provide an analysis of downwash effects for any stacks
significantly less than GEP height. The technical support document for
the GEP regulations will guide the reviewer on how these analyses should
be performed. If a source intends to construct a stack that exceeds GEP
height, the source must model at GEP height. Each stack should undergo
an analysis by the reviewing authority to determine that the GEP
regulations are met.
C.I.4 Existing Air Quality
Data must be presented by the applicant to establish the air quality
in a region prior to the introduction of a new source or modification.
The determination of existing air quality usually takes place well in
advance of the submittal of a PSD application. It includes either a
demonstration that existing monitoring data are adequate to measure
maximum concentrations in the source impact area or the results of a
monitoring program conducted specifically for the proposed source or
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modification. Remember that the applicant may apply for an .exemption
from the monitoring requirements upon demonstration of sufficiently low
ambient impacts or existing ambient air concentrations. In all cases,
the applicant must follow the Ambient Monitoring Guidelines for Prevention
of Significant Deterioration. The reviewing authority should review
each air quality analysis carefully with respect to the PSD guideline.
C.I.5 Class I Areas
If a Class I area is within the air quality impact range of the
source proposed by the applicant, then special care must be taken by the
reviewer to ensure that all modeling procedures are precise. The Class I
area analysis is more complex for the applicant because Class I increments
are much smaller than Class II increments. The procedures for establishing
an inventory and for modeling are the same as applied in Class II areas;
however, the applicant must consider carefully all increment consumption
at a Class I area. In these cases, little room is left for error.
C.2 SUMMARY i
All modeling results presented by the applicant should be carefully
reviewed. The modeling results should be substantiated by computer
printouts from the modeling analysis. The reviewer should verify that
an appropriate model has been applied properly and that the data presented
is complete and accurate.
The job of the reviewer is critical to the preservation of the
national ambient air quality standards and the PSD increments. The
reviewer should address all data presented by the applicant with the
intention of certifying that a thorough analysis of the predicted air
quality around the source in question has been conducted. The critical
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items that should be reviewed with respect to air quality impacts
follow:
t A determination of those pollutants for which a review is
required,
A clear description of the proposed source or modification,
The proper selection and use of models,
A determination of existing air quality,
An analysis of any impacts on a Class I area, and
t A demonstration of compliance with the NAAQS and PSD
increments by a careful examination of all results.
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APPENDIX 1
PRELIMINARY DETERMINATION SUMMARY
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D. ADDITIONAL IMPACTS ANALYSIS
A critical part of any PSD application is the additional impacts
analysis, which is an analysis of the impacts of the proposed source or
modification and its associated growth upon the soil, vegetation, and
visibility in the areas surrounding the source. This section will
provide the reviewer with a checklist to help ensure that the additional
impacts are adequately defined and properly documented. The checklist
contains a number of points the reviewer should consider before beginning
a review of the additional impacts section of a PSD application.
Initially, the reviewer should determine the depth of analysis.
necessary for the particular source or modification under review. For
example, the reviewer may reasonably assume that large sources of emis-
sions, such as power plants and smelters, will probably require an
extensive analysis. The depth of analysis for smaller sources of emis-
sions should depend upon the air quality in the area and the sensitivity
of local soils, vegetation, and visibility to the indicated air pollution
impacts. The reviewer also should be aware of the location of the
nearest Class I area. The additional impacts analysis must address
potential impacts in Class I areas in greater detail than in other
areas.
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The 1980 PSD regulations require air quality analyses for both
criteria and noncriteria pollutants that are emitted or increased in
significant amounts. The predicted ambient air concentrations are used
as a basis to assess the extent of soil, vegetation, and visibility
impacts. Because national air quality standards for noncriteria pollu-
tants do not exist, the additional impacts analysis serves a major role
in establishing the air quality impacts of these pollutants.
Finally, the reviewer should note that applicants have a great deal
of flexibility in their approach when undertaking an additional impacts
analysis. It is the reviewer's responsibility to determine if the
analysis presented by the applicant has been completed with sufficient
depth to determine potential significant effects on soils, vegetation,
and visibility resulting from air quality impacts. The reviewer must
rely on information presented by the applicant as well as on his or her
experience in determining the adequacy of the analysis.
Other major considerations of the additional impacts analysis
review are presented below.
0.1 GROWTH ANALYSIS
In a growth analysis, the applicant must present a clear picture of
the resulting air quality impacts after the source or modification is
introduced. The application should project direct industrial, commercial,
and residential growth, and the reviewer should decide whether the data
presented are reasonable. It is important that the reviewer query
regional planning offices or other State agencies to verify the data
presented by the applicant. The reviewer may also check other PSD
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applications that are similar to the one under review. In addition, the
reviewer should be able to delineate those types of situations that may
lead to associated growth. For example, a labor-intensive industry,
such as a large furniture manufacturing plant or textile mill built in a
small, rural town, may result in increased residential and commercial
growth that would affect the air quality of the area.
The growth projection analysis should be the first analysis undertaken
by the applicant because it provides inputs into the modeling analysis,
which in turn provides an essential framework for the soils, vegetation,
and visibility analyses. In many cases, the reviewer must rely on data
presented by the applicant to determine the type and amount of expected
growth. If insufficient data are presented for review, the reviewer
should request additional information from the applicant.
If the reviewer is in agreement with the projected growth analysis,
the next step is to assess the data on air pollution that may result
from this growth. Temporary growth, such as a construction work force,
does not necessarily apply; therefore, data on emissions from temporary
growth are generally not considered. The applicant should make logical
conclusions from an analysis of the area and should address both long-term
and short-term growth. The reviewer should verify the projected emissions
by referring to manufacturer's specifications and guidelines, or by
comparing the data to similar examples of growth and emissions found in
other PSD applications. Additionally, the EPA publication, Compilation of
Air Pollution Emission Factors (AP-42), is a good source of emissions
data. The reviewer should also verify that all significant quantifiable
emissions projected in the growth analysis are considered in the modeling
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analysis, because both applicable criteria and noncriteria emissions
should be modeled. If no growth is projected as a result of the intro-
duction of a new source or modification, then there will be no growth-
related air quality impacts. Once the reviewer has a clear understanding
of growth and its impacts, the next consideration in the additional
impacts analysis should be the soils and vegetation analysis.
D.2 SOILS AND VEGETATION ANALYSIS
The soils and vegetation analysis examines the effect of predicted
ambient air concentrations on soils and vegetation. The applicant could
have approached the analysis from a variety of viewpoints; therefore, it
is the reviewer's task to check any analysis for accuracy and credibility.
An applicant who has followed the suggested method of analysis will
provide a categorization of the soil and vegetation types found naturally
in the area. The reviewer should verify that this list is accurate and
comparable to the assessments of other conservation groups, State agencies,
or universities. The soils and vegetation survey is very important and
should emphasize the sensitive species located in the area.
Reviewers should examine the modeling data presented in the PSO
application to. determine the maximum pollutant concentrations of each
applicable pollutant in the impact area. The modeling should include
applicable criteria and noncriteria pollutants. The applicant should
present predictions, supported by scientific literature, of the effects
of maximum concentration of pollutants on the types of soils and vegetation
found within the impact area. Good references include the EPA Air
Quality Criteria Documents and a U.S. Department of the Interior document
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entitled Impacts of Coal-Fired Power Plants on Fish. Wildlife, and Their
Habitats.
For criteria pollutants with maximum predicted concentrations that
are less than the secondary national ambient air quality standards, the
impact on most soils and vegetation, in most cases, will be negligible.
Because some sensitive species of plants may be directly affected by
these lower concentrations, the list of vegetation for a particular area
should emphasize these sensitive species. For example, alfalfa yield is
decreased when alfalfa is exposed to sulfur dioxide (S02) concentrations
of less than 100 micrograms per cubic meter for a period of 4 weeks.
The reviewer must check any supporting documentation provided to ensure
that the conclusions of the applicant are correct.
D.3 VISIBILITY ANALYSIS
In the last step, the reviewer should assess the applicant's visibility
impacts analysis. Air pollution visibility impacts include visible
stack emissions, mists associated with cooling towers, and any trans-
formation of pollutants involved in atmospheric chemistry.
An assessment of visibility impacts, like all additional impacts
analyses, is based on comprehensive data presented by the applicant.
Data correlating emissions with visibility impacts must be properly
applied. Currently, the suggested method for completing the visibility
impairments analysis is the screening techniques outlined in the draft
EPA document, "Workbook for Estimating Visibility Impairment." If the
applicant has utilized the workbook as a guide, the reviewer should
verify all calculations and conclusions presented by the applicant. If
the applicant used a different method of analysis, the reviewer should
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check to see that the analysis is correct and should verify the applicant's
conclusions by performing a separate visibility screening analysis.
This technique is not time-consuming and serves as an excellent verifica-
tion procedure.
For large sources of emissions resulting in possible visibility
impairments, applicants have been urged to utilize the plume visibility
model. The reviewer should consult with the regional meteorologist to '
verify both the proper application of the model and the results submitted
by the applicant. The reviewer also should be familiar with the draft
EPA document, "User's Guide for the Plume Visibility Model."
A major goal of the additional impacts analysis is to provide the
local community with information that demonstrates how a new source will
affect their enjoyment of the area. Areas that contribute to the common
aesthetic enjoyment of a community should be part of the application.
It is the responsibility of the reviewer to ensure that all the information
presented by. the applicant is descriptive.
The applicant must also submit an expanded visibility impairment
analysis when primary or secondary emissions affect Class I areas or
other areas of scenic beauty. Any potential impacts on Class I areas
must be reviewed in a manner that adequately addresses the impacts on
the recreational and scenic beauty of these areas.
D.4 CONCLUSIONS
After the reviewer has carefully examined all data on additional
impacts, he or she must decide whether a particular applicant has met
the standards of the review.
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This decision is based on:
Whether the applicant has given the reviewer a clear and
accurate portrait of the soils, vegetation, and visibility
in the proposed impacted area.
Whether the applicant has provided adequate documentation
of the potential impacts upon soils, vegetation, and
visibility resulting from applicable pollutant emissions.
Whether the data was presented in a logical manner (i.e.,
beginning with a growth analysis, followed by a visibility
analysis, etc.)
Whether the applicant, the reviewer, and the affected
community understand the potential additional impacts
generated from the source under review.
The additional impacts are sensitive community issues and must be
properly assessed and clearly presented if a harmonious relationship is
to exist between industry and the local community.
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PRELIMINARY DETERMINATION SUMMARY
CONTENTS & FORMAT
I. APPLICANT'S NAME
MAILING ADDRESS
II. PROPOSED SOURCE OF MODIFICATION LOCATION
County or Parish
UTM coordinates or longitude and latitutde
Street or road location
III. PROJECT DESCRIPTION
Generalized description of project and process weight rate, new, or
modified. Emphasis should be on capacity or firing rate,
IV. SOURCE IMPACT ANALYSIS
This section should deal with an introduction as to what items the
application was reviewed for:
1. BACT
2. NAAQS analysis
3. Increment analysis
4. Soils, visibility, and vegetation
5. Growth
6. Class I area analysis
The following discussion should backup or give the appropriate
reasons why the application was reviewed for some or all of the above
items.
Quote the appropriate paragraph number in the PSD regulation which
demonstrates proper applicability or exemption.
This section should also include a statement and demonstration of
the pollutants for which the source is considered major. Provide a
table, labeled "Table I," showing emissions of all pollutants being
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emitted at the source and those associated with the major source or
major modification.
If applicant is required to perform an air quality review, copies
of Table 1-1 and Table 1-2 must be included in the POS. Revised copies
of these tables are attached for use. They would be included in the
preliminary determination summary (POS) as Tables 2 and 3.
A. BACT
This section must discuss the applicant's proposed BACT. The
alternatives must be discussed for each facility that emits (or increases)
the emissions of an applicable pollutant.
For instance:
1.
2.
TSP
a.
b.
c.
SOg
a.
b.
Coal conveying
Boilers X & Y
Fly ash silo
Boiler X
Boiler Y, etc.
If the resulting BACT is or results in emissions different than any
applicable NSPS, give rationale.
Note: We do not want to issue a permit with an. allowable emission so
low that we feel it is unattainable even though the applicant feels he
can meet it.
B. Increment Analysis
(This section, of course, is needed only for applicants subject to
PSD for TSP or S02.)
This section must contain the following minimum information:
1. Computer model used, highlighting any modifications and why it
was used and approved for use.
2. If appTvcant used resulting highest, second-highest values
then he-must use 5 years meteorological data. State whether
the numbers reflect highest or highest, second-highest values.
3. The maximum impact area for TSP and/or S02.
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4, List of other increment-consuming sources in the impact area
and the source of this information such as the applicant or
State agency, etc.
5. The maximum increment consumed as a result of the application.
Note: Increment analysis is by modeling only and has nothing
to do with monitored background data!
C. NAAQS Analysis
This section must contain a brief explanation of how the applicant
obtained his conclusion; which monitor provided the background readings
and which other sources in the area were modeled. This is a case-by-case
analysis which must demonstrate that good engineering logic was used.
The results should be in tabular form showing background plus other
sources contributions plus the applicant's contribution and the resultant
sum to arrive at the predicted worst case.
Also, state whether the applicant has demonstrated that Good
Engineering Practice (GEP) has been applied to all emitting stacks and
that no NAAQS violations are expected to occur as a result of downwash.
D. Soils, Vegetation, Visibility
This section should include a summary of the applicant's statement
regarding anticipated harm to any of the above. Cite appropriate references
and studies used for the applicant to reach his conclusions.
E. Growth Impacts
This should include a statement regarding any deterioration of air
quality due to secondary emissions from associated industry, local rush
hour traffic from employees, future phases of the project, etc.
Also, a statement should be made here about availability of future
growth and increment consumed by this project.
F. Class I Area'Analysis
State what impact, if any, will result from the project. Also
state whether the source is (or is not) within 100 km of any Class I
area.
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V. CONCLUSIONS
This section should begin with a recommendation of approval or
disapproval and the items of correspondence upon which the recommendation
is made.
The remainder of this section is specific permit conditions:
1. Applicant will verify all emissions within 90 days of startup
according to EPA methods of 40 CFR 60 etc.
2. Provide a table of allowable emissions, BACT, etc.
For instance:
TSP
Faci1ity BACT % Pollutant Reduction Allowable Emission
Note: Provide values, where applicable or available. Allowable
emissions should be in the Ibs/hr or Ibs/million Btu heat input for
combustion equipment.
3. For power-generating stations, the applicant should provide
description of final design and received EPA approval before
ordering equipment.
4. Any other condition(s) needed to ensure that EPA is not allowing
any emissions greater than the modeling results were based on.
This, might include shutdown of equipment being replaced when
new equipment Is started up, etc.
5. Cite appropriate compliance methods.
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Table 1-1. NATIONAL AMBIENT AIR QUALITY STANDARDS
Pollutant
Sulfur dioxide
Particulate matter
Carbon monoxide
Nitrogen dioxide
Ozone
Lead
Averaging time
Annual
Arithmetic mean
24 - Hr. ?
3- Hr.b
Annual
Geometric mean
24-Hr.b
8- Hr.!;
l-Hr.b
Annual
Arithmetic mean
1- Hr.b
Calendar Quarter
Ambient ceilings,3
ug/m3
80
365
1,300
75
150
10c
40C
100
235
1.5
The lower concentration of either the primary or secondary NAAQS.
Not to be exceeded more than once per year.
cMi11i gram/meter3,
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Table 1-2. CLASS II INCREMENTS
Maximum allowable
increases (increments)
Pollutant Averaging time micrograms/meter3
Sulfur dioxide Annual mean 20
(S02) 24 - Hr. 91*
3 - Hr. 512a
Parti cul ate-matter Annual mean 19
(TSP) 24 - Hr. 37a
aThe applicable maximum allowable increase may be exceeded during
one such period per year at any receptor site.
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APPENDIX 2
PSD COMPLETENESS DATA SUMMARY
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COMPANY NAME:_
PSD NUMBER:
PSD COMPLETENESS DATA SUMMARY/REVIEW WORKSHEET
REVIEW DATE:
NMS or MM (circle one) REVIEWER:
BRIEF PROJECT DESCRIPTION
I. DETERMINATION OF APPLICABILITY
For Proposed Construction, PSD Review - Applies - Does Not Apply - Undetermined* (Circle One)
*The following Information 1s needed to complete the determination:
REVIEW REQUIREMENTS ARE AS FOLLOWS (1f subject to review):
Pollutant BACT Monitoring
PM
SO.
N0x
cox
O-(VOC)
Oth6r
Other
SIGNATURE OF REVIEWER:
Add'l Impacts
Net Emissions
Increase (T/yr)
1. POTENTIAL EMISSIONS DATA SUMMARY FOR THE SOURCE (proposed new source or the
existing source for a proposed modification):
Basis for Estimates
PF Emission % Emissions Actual Allowable
Pollutant (T/yr) Units hrs/day hrs/yr Capacity Factor (T/yr) (T/yr)
PM
COX
0?(VOC)
Other _
Other _
a. The source, is a _ 28-listed source or is a _ non-28-Hsted source
(100/250 major emissions criteria respective! yj!
b. If less than 8760 hrs/yr and 100X, do enforceable restrictions exist? _ yes
c. If PE, actual and allowable are not equal, explain why:
no.
2. NET CHANGES IN ACTUAL EMISSIONS? (for modifications only).
Describe modification including previous or planned emissions changes:
Pollutant
PM
SO,
N0x
COX
0,(VOC)
Other
Other
New
& Mod.
Units
(T/yr)
Creditable Creditable
Con temp. Contemp.
Increases Decreases
(T/yr) (T/yr)
Net
Change
in actual
(T/yr)
Significance
Criteria0 (T/yr)
25
40
40
100
40 (VOC)
A. Are decreases ensured by enforceable restrictions? yes no.
±L. Is the source within 10 km of any Class I area? yes no.
If so, is maximum air impact (discussed below) >_ 1 ug/m3 (24^hr)? yes
c. The baseline date(s) for this area are: ~
d. Do claimed emissions changes occur: 1) after 1/6/75yesn
2) after baseline date yes no (Note: Prebaseline changes i
be due to construction at a MSS).
. The area is designated non-attainment for what pollutants?
2-1
no.
no;
changes must
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BIBLIOGRAPHY
U.S. Department of Health, Education, and Welfare. 1967. Air Pollution
Engineering Manual. Publication No. AP-40. Cincinnati, Ohio.
987 pp.
U.S. Department of the Interior. 1978. Impacts of Coal-Fired Power
Plants on Fish, Wildlife, and their Habitats. Fish and Wildlife
Service Publication No. OBS-78/29. Washington, D.C. 259 pp.
U.S. Environmental Protection Agency. 1980. User's Manual for the Plume
Visibility Model. Research Triangle Park, North Carolina. 377 pp.
(Draft Document submitted to EPA.)
. 1980. Workbook for Estimating Visibility Impairment. Research
Triangle Park, North Carolina. 373 pp. (Draft document submitted
to EPA.)
. 1978. Ambient Monitoring Guidelines for Prevention of Significant
Deterioration. EPA-450/2-78-019. Research Triangle Park, North
Carolina. 90 pp.
. 1978. Guideline on Air Quality Models. EPA/450-2-78-027. OAQPS
No. 1.2.-080. Research Triangle Park, North Carolina. 83 pp.
. 1977. Compilation of Air Pollutant Emission Factors, 3rd ed.
(including Supplements 1-7). Publication No. AP-42. Research
Triangle Park, North Carolina. 500 pp.
. 1977. Guidelines for Air Quality Maintenance Planning and Analysis,
Volume 10 (Revised): Procedures for Evaluating Air Quality Impact
of New Stationary Sources. EPA-450/4-77-001. OAQPS No. 1.2-029R.
Research Triangle Park, North Carolina. 75 pp.
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