-------
30
statistically significant at the .05 level requires that a positive difference
be found in at least 56 of the pairs. Positive differences actually occur in
58 of the 95 pairs. It can therefore be said that, at the .05 level of signi-
ficance, an observed value of Q will be greater than the corresponding calcu-
lated value. By dichotomizing the differences, we have sacrificed the
possibility of being able to say by how much the observed value might be
expected to exceed the calculated one.
In the GEOMET report of analyses of the entire quantity of observed
data, it is noted that measurements during the control phase are less than
baseline measurements by from 14% to 38%, depending on the assumed meteoro-
logical basis used for comparison. These are uncorrelated comparisons with
no attempt made to match identical hours between the two phases. All attempts
to associate these changes with the control procedures proved unsuccessful,
however. The changes for hours when the procedures should have had relatively
little impact because of the low level of arrival activity were found to be
indistinguishably different from those for hours dominated by arrival acti-
vity; changes of approximately 201 were pervasive. The suggestion is made
that the measured difference might in fact be due to a curtailment of auto-
motive traffic on peripheral highways due to the increasing shortage of gasoline
over the test period. There is evidence from the record of carbon monoxide
measurements taken by the Georgia Department of Natural Resources at its long-
term monitoring site in downtown Atlanta that a decrease in concentrations
between November and December might have been regionwide. When 24-hour averaged
values of carbon monoxide levels in downtown Atlanta for the last two weeks
in November and for the first two weeks in December are compared, the December
values are found to average 33% lower than the November ones. Whatever the
cause of this decrease, it is very possible that it has obscured the monitored
evaluation of the test procedures.
3.2.4 Validation Implications
Based on the above validation analysis, it must be said that the
model does not correlate with the observed data as well as would be desired.
Several explanations for the discrepancy can be offered. First, the emission
inventory used in the model cannot be made to exactly replicate the actual
emission pattern within the bounds of reasonable resource expenditure. This
-------
31
is especially true with regard to the environ emission inventory. The whole
modeling concept relies on the simulations of average conditions wherein
transient variations are obscured. In the field test program there was an
insufficient amount of data collected to satisfy the "average condition" re-
quirements. All participants in the program recognized the problems of the
short test period but insufficient resources were available to correct the
situation- In conjunction with this problem, the unfortunate coincidence of
the national fuel shortage in the middle of the test program introduced
another perturbation that could not be simulated with the available data. As
was previously discussed, the fuel shortage may have contributed to the large
(33%) reduction in CO concentrations observed at the Georgia Department of
Natural Resources monitoring sites. The unusual behavior of the observed Q
distribution (Fig. 6.b.) indicates the possible scope of the problem.
A second possible explanation for the discrepancies is the rather
narrow range of CO concentrations observed as well as the small absolute
concentrations (all less than 2.5 ppm from Fig. 5). Measurements are difficult
in this range and small equipment problems can result in substantial errors
in the data.
In addition to the data problems, the model itself appears to be
underpredicting CO concentrations. The relatively large intercepts of the re-
gression lines indicate an unaccounted-for background level. This level is
of the same order of magnitude as the absolute values and hence represents a
significant portion of the actual concentration.
Despite the rather weak validation here, the model has been shown
9 10
in other cases. ' to do a respectable job in describing temporal and spatial
changes in air quality. The justification for its use in the following analyses
is predicated, then, primarily on the previous validation results rather than
on those available from the field test program, which are, at best, inconclusive.
Interpretation of the results must, therefore, be made with this caveat in
mind.
Although it would be desirable to establish confidence limits on the
model calculations, this cannot be done here because of the uncertainties in
the observed data. Rather, it can be said that the relative changes in calcu-
lated air quality effected by each control strategy will probably be a reasonable
-------
32
estimate of what might be expecte:! in practice. Additional validation work
would be necessary to support a stronger statement about the accuracy of the
calculations.
-------
33
4.0 CONTROL STRATEGIES
4.1 BASELINE CONDITIONS
In the following analyses the baseline conditions against which the
various control strategies are evaluated are taken to be those existing in
the initial weeks of the field test program. Normal operating procedures
at the Atlanta airport are assumed and air traffic volume and fleet mix as
observed in late 1973 are used as the reference values; Table 5 gives this
pattern. Runway use is assigned on the basis of wind direction with traffic
being split between the northern runway (8/26) and the southern runways (9L/
27R, 9R/27L) in the ratio of 60/40. The northern runway is preferred because
of its proximity to the terminal. Aircraft ground taxi paths and taxi speeds
were those observed during the field test.
4.2 ENGINE SHUTDOWN
This strategy is designed to reduce carbon monoxide and hydrocarbon
emissions during aircraft taxi/idle operation. Since a large fraction of the
aircraft's emissions of these pollutants occurs during taxi/idle, the strategy
offers promise of significant overall emission reduction. As was demonstrated
at the Atlanta airport, the procedure can be implemented at an existing airport
with a minimum of effort and no additional expenditures. (In fact, the resulting
fuel conservation is a cost saving.)
The engine shutdown strategy evaluated here is the same as that
employed at the Atlanta airport during the field test. The strategy achieves
emission reductions in two ways. First, the operation of fewer engines reduces
the overall aircraft emission rate; second, the operation of the remaining en-
gines at higher power settings (to maintain taxi speed) moves them closer to
their maximum performance design conditions and hence reduces the engine
emission rate. Both of these conditions were simulated in the AVAP model.
Five of the aircraft types included in the model participated in the
engine shutdown test (Amber Test) either inbound or outbound as was shown on
Table 1 (DC-8 and B-707 aircraft were modeled as a single type). The model
contained two tables for the number of engines used by each aircraft. For the
description of Amber Test procedures, the first table was filled with the total
number of engines on each aircraft and the second contained the number of en-
-------
34
TABLE 5. Temporal Distribution of Aircraft at the Atlanta Airport
Aircraft
Type
DC-9
B-727
DC-8
MR-404
CV-880
Be-99
YS-11
B-737
B-747
L-1011
DC-10
GA-Jet
GA-Pist.
Total
Aircraft
Type
DC-9
B-727
DC-8
MR-404
CV-880
Be-99
YS-11
B-737
B-747
L-1011
DC-10
GA-Jet
GA-Pist.
Total
Annual
LTOs 1 2
99,155 4.3 1.3
75,190 5.2 2.0
24,820 6.4
8,395
5,110
16,495
5,240 3.4
7,665
2,555
1,460
730 20.0
8,365 1.7 3.6
5,975 1.7 3.6
252,755
Annual
LTOs 13 14 15
99,155 6.3 4.0 6.9
75,190 4.8 2.7 4.0
24,820 5.7 .7
8,395 2.1 4.2 4.2
5,110 4.5 4.5
16,495 2.9 5.7 14.3
5,240 6.9 3.4
7,665 1.9 9.6 9.6
2,555
1,460 7.7
730
8,365 5.0 5.2 7.0
5,975 5.0 5.2 7.0
252,755
Diurnal Pattern (4 of daily total)
tour
345 6 789 10 11
.2 1.2 4.5 3.7 1.6 4.7 4.] 5.7
.9 1.0 2.0 4.5 4.5 .9 3.0 5.5 6.2
.7 4.3 7.1 .7 6.4 9.3
2.1 8.3 8.3 12.5
13.6 4.5 22.7
8.6 8.6
3.4 6.9 6.9 6.9
1.9 5.8 9.6 11.5
14.3 14.3 7.1
7.7 7.7 7.7 7.7
20.0 20.0
7.8 5.4 2.2 1.5 1.2 1.6 3.] 4.7 5.2
7.8 5.4 2.2 1.5 1.2 1.6 3J 4.7 5.2
Diurnal Pattern ($ of daily total)
Hour
12
6.6
8.2
5.0
8.3
1.5
14.3
3.4
5.8
5.5
5.5
16 17 18 19 20 21 22 23 24 Weekday/Weekend
6.5 4.3 4.0 4.9 6.1 5.7 4.7 3.7 5.1 .143/
5.5 4.5 5.5 6.5 4.7 7.0 3.0 2.2 5.5 .143/
7.9 5.7 5.0 7.1 10.0 5.0 1.4 7.1 .143/
4.2 6.2 6.2 6.2 8.3 12.5 4.2 2.1 .143/
18.2 9.1 9.1 4.5 4.5 .143/
8.6 2.9 17.1 2.9 11.4 2.9 .143/
3.4 10.3 10.3 6.9 6.9 3.4 10.3 6.9 .143/
3.8 5.8 7.7 3.8 9.6 3.8 1.9 3.8 3.8 .143/
7.1 14.3 7.1 7.1 14.3 7.1 7.1 .143/
7.7 15.4 7.7 7.7 7.7 15.4 .143/
20.0 20.0 .143/
6.0 6.7 7.2 5.4 4.6 3.4 3.6 2.6 1.7 .161/
6.0 6.7 7.2 5.4 4.6 3.4 3.6 2.6 1.7 .161/
.143
.143
.143
.143
.143
.143
.143
.143
.143
.143
.143
.098
.098
-------
35
gines used during the application of the control strategy. The model associ-
ated the use of one or the other of the engine number tables separately with
each taxiway segment and provided for a different choice for inbound and out-
bound taxiing for each segment. A further consideration was required to treat
the fact that the effect of control procedures is not uniform among the parti-
cipating aircraft: DC-9s participated only outbound, DC-8s and CV-880s partici-
pated only inbound, and B-727s and DC-lOs participated both inbound and out-
bound. This aspect was handled by overriding the use of the control phase
engine number table for inbound DC-9s and for outbound DC-8s and CV-880s and
forcing the normal table to be used in those circumstances.
Outbound engine shutdown was modeled only over that portion of the
taxi path between the designated shutdown and restart points (see Fig. 3 and
accompanying text). Outbound controls were seldom activated, because few
periods of excessively long delay were encountered during the test program.
In the model's queuing simulation, the aircraft queue length, averaged over
an hour, was not long enough under the normal range of conditions to extend
onto the controlled portion of the taxi path. For most of the computer runs,
therefore, outbound engine controls were not used. In one set of runs, however,
with assumed worst case meteorological conditions and four times normal queuing
length, outbound reduced engine operation was modeled for both taxiing and
queuing emissions.
The change in engine pollutant emission rates accompanying the
slightly higher power setting of the remaining operating engines was simulated
by assuming that the thrust would be increased linearly. For a two-engine
aircraft (e.g. DC-9), the power setting on controlled taxi segments for the
one operating engine would be 100 percent higher than for normal taxiing.
Although the percentage change in power setting is large for all aircraft par-
ticipating in Amber Test, the absolute change represents only a small portion
of the full range of engine power settings. Linear approximations to the
emission rate vs. power setting curves are justified over this small range
and were used as the basis of the emission rate change modifications added to
the model.
The JT8D engine used on DC-9, B-727, and B-737 aircraft can be used
as an example of the modifications made to simulate engine shutdown. The degree
of participation is different for each of these aircraft as indicated in
-------
36
Table 6, which also lists the number of engines per aircraft (from the first
engine number table in the model) and the number of engines operating during
the control phase of Amber Test (from the second engine number table in the
model). Emission rate curves for the JT8D engine are displayed on Fig. 7;
these curves were generated from the emission rates at the four engine mode
settings which are related to fractions of full engine power for the purposes
of these curves. Under baseline conditions the engines on all three aircraft
types were operated at 6% of full power with a carbon monoxide emission rate
of 15.2 kg/hr for taxiing as shown on Table 6.
TABLE 6. Comparison of the Effects of Engine Shutdown
on the Carbon Monoxide Emission Rates of
Three Aircraft Types Using JT8D Engines
Degree of participation
in Amber Test
Number of engines
Taxi emission rate per
DC-9
Departures
only
2
15.2 kg/hr
Aircraft Type
B-727
Arrivals and
departures
3
15.2 kg/hr
B-737
Exempt
2
15.2 kg/hr
engine during baseline
conditions
Taxi emission rate per 30.4 kg/hr 45.6 kg/hr
aircraft during baseline
conditions
Engines operating on 1 2
controlled taxi segments
during engine shutdown
strategy
Taxi emission rate per 13.5 kg/hr 14.4 kg/hr
engine on controlled
taxi segments
Taxi emission rate per 13.5 kg/hr 28.8 kg/hr
aircraft during engine
shutdown
30.4 kg/hr
15.2 kg/hr
30.4 kg/hr
-------
37
Pt
0 20
TAXI
1.2
1.0
0.8
0.6
0.4
0.2
0 _J
40 60 80 100
APPROACH CLIMBOUT TAKEOFF
% OF FULL ENGINE POWER
0
Fig. 7. Rates of Pollutant Emissions from a JT8D Engine
as a Function of Relative Power Setting
-------
38
On arrival taxiways during the engine shutdown phase of the program,
JT8D engine operation was changed for only the B-727 aircraft, which shut down
one engine after leaving the arrival runway. Segments of arrival taxiways
between the runway turnoff points and the terminal parking areas were, there-
fore, modeled to use only 2 engines for the B-727. A straight-line approxi-
mation to the carbon monoxide emission rate curve in the vicinity of the engine
power setting for taxiing shows that a 50% increase in power for the two
operating engines on inbound B-727s results in a decrease in the engine emis-
sion rate to 14.4 kg/hr. On arrival taxiways the DC-9 and B-737 aircraft are
modeled as operating with their full complement of engines at the normal 6%
power setting.
The simulation of the engine shutdown strategy for departures affected
only the intermediate segments of departure taxiways. For these segments DC-9s
and B-727s operated with one less engine, and the engine number values shown
on Table 6 are effective in the model. The increase of 100 percent in power
for the remaining operating DC-9 engines results in a carbon monoxide emission
rate decrease to 13.5 kg/hr, based on the linear approximation of Fig. 7. Air-
craft emission rates on the controlled segments of outbound taxiways, therefore,
are reduced to 13.5 kg/hr for DC-9 and 28.8 kg/hr for B-727 aircraft. The
B-737 emission rate is unchanged as are the rates for all other portions of
the outbound taxiways.
In a similar fashion, the modified emission rates were developed for
all aircraft participating in the test as shown in Table 7.
4.3 AIRCRAFT TOWING
2 4
This strategy was suggested by EPA ' as a means of reducing a sub-
stantial portion of the taxi/idle emissions by having aircraft towed between
the duty runway and the terminal by a tractor. Although emissions could be
substantially reduced by implementation of this technique, it presents some
operational problems that would foreclose immediate application at existing
airports. In order to avoid air traffic delays, the towing vehicle would have
to maintain the same taxi speed as normally operating aircraft (about 40 km/hr
with no impediments). Nose wheel gear on most aircraft are not designed for
the extended horizontal loading that would result and would require struc-
tural reinforcement. Some aircraft are equipped with fuselage-mounted towing
-------
39
TABLE 7. Taxi/Idle Emission Rates for Aircraft
Participating in Engine Shutdown Test
Engine Type
Number of Engines
Normal Taxi/ Idle
Emission Rates
CO
HC
NOX
Number of Engines
in Use During
Participation in
Shutdown Strategy
Modified Taxi/ Idle
Emission Rate
00
HC
NO
Jv.
Emission Rate
(kg/hr)
DC-9 B-727 DC-8
JT8D JT8D JT3D
234
30.40 45.60 197.60
7.42 11.13 178.80
2.64 3.96 2.60
123
13.55 28.76 140.37
2.45 6.16 119.10
2.77 4.08 2.95
CV-880 DC-10
CJ805 CF6
4 3
115.60 70.50
49.60 21.00
2.85 4.89
3 2
85.44 42.98
33.99 11.72
2.79 8.14
-------
40
hooks, but special equipment would have to be designed to make regular use of
them. There are numerous safety complications that must also be considered.
Despite the operational problems, the strategy offers some interesting possi-
bilities for emission reduction and so is evaluated here.
In the model simulation, departing aircraft are towed from the
terminal gate to the end of the duty runway. Engines are started just prior to
positioning for takeoff. For arriving aircraft it is assumed that all engines
are shut down after clearing the arrival runway. The strategy is applied to
turbine engine aircraft only.
To simulate the emissions of the towing vehicle, the aircraft taxi-
idle emission factor was replaced by the tractor's emission factor. Table 8
compares the tractor emission rate to that of the aircraft. It can be seen
that the use of the tow tractor reduces the emission rates by at least an order
of magnitude in all cases.
TABLE 8. Comparison of Tow Tractor and Aircraft Taxi-Idle Emission Rates
Pollutant Emission Rate
(kg/hr)
Tow Tractor
DC-9
B-727
DC-8
CV-880
B-747
DC-10
CO
1.92
30.40
45.60
197.60
115.60
185.20
70.50
HC
.30
7.42
11.13
178.80
49.60
49.60
21.00
NOx
.13
2.64
3.96
2.60
2.86
11.00
4.89
Pt
.02
.32
.48
.80
2.36
4.00
.06
4.4 CAPACITY CONTROL
The capacity control strategy relies on the reduction of overall air-
craft activity by increasing the passenger load factors. By imposing the re-
quirement for increased utilization of available seats, fewer aircraft would
be required to transport the same number of people.
-------
41
It would be unrealistic to assume that this strategy could be imposed
at a sin-He airport without consideration of the national picture. The complex
nature of the route structure would require a detailed analysis of the implica-
tions '«! fewer available seats on the economic status and quality of service
of Lha airlines. The strategy is evaluated here as a consideration of what the
impact of a national policy to reduce aircraft activity by increasing passenger
load factors would be at the Atlanta airport.
The parametric load factor used to define this strategy is the ratio
of the number of occupied seats to the number of available seats. Based on
questionnaire data, the load factor at the Atlanta airport varied between 48%
and 64% among the airlines for the period of late 1973. The overall average
load factor was 62%. The strategy, as studied here, involved the reduction
of the number of air carrier flights while maintaining the fleet mix distribu-
tii/.i constant. General aviation activity was unchanged. Model runs were made
w;-?.h iovd factors of 65% and 70%. Higher load factors were not used because
it waf anticipated that they would have serious effects on the quality of service.
Cable 9 gives the aircraft activity for each load factor. It can be seen that
overall activity is reduced by about 4% and 121 by increasing the load factor
to o£'i arid 701, respectively.
TABLE 9. Aircraft Activity with Varying Load Factors
Aircraft Activity
(LTOs/year)
Aircraft
T>pe
r\>0
e ?:''
i~£-£
.Y- :v:?,n
j<- .V ''
B-747
L-1C11
r)(>jQ
3B-99
MR - U!4
YS-1I
3en. Av. - Jet
Gen, %. - Piston
Total
Baseline
Load Factor
62%
90,155
75,190
24,820
5,110
7,665
2,555
1,460
730
16,495
8,395
5,840
8,365
5,975
252,755
Load Factor
65%
86,008
71,731
23,678
4,875
7,312
2,437
1,393
696
15,736
8,009
5,571
8,365
5,975
241,786
Load Factor
70%
79,877
66,618
21,990
4,526
6,791
2,280
1,294
647
14,61f
7,438
5,I7<
8,:.'
5,9'j
225,590
-------
42
4.5 FLEET MIX CONTROL
The report oa the initial phase of this program indicated that the
trend toward the newer wide-body aircraft would result in lower per-passenger
emissions at the study airport (St. Louis in that case). The fleet mix strategy
studied here was designed to evaluate the impact that an acceleration of that
trend might have at the Atlanta airport. As with the capacity control stra-
tegy, it is not possible to consider the imposition of this control measure
at a single airport; national route requirements must be evaluated.
To simulate the strategy it was assumed that the same number of air
carrier seats would be available as under baseline conditions. The fleet mix
13
forecasted for the Atlanta airport in 1980 was used to generate the aircraft
activity pattern. General aviation activity was unchanged. Table 10 compares
the new fleet mix to baseline conditions.
TABLE 10. Fleet Mix Change
Fraction of Total Aircraft Activity
Aircraft
DC-9
B-727
DC- 8
CV-880
B-737
B-747
L-1011
DC -10
Be-99
MR- 404
YS-11
Gen. Av. - Jet
Gen. Av. - Piston
Basel ine
.357
.298
.098
.020
.030
.010
.006
.003
.065
.033
.023
.033
.024
Fleet Mix
Strategy
. 333
.230
0
0
.042
.081
.082
.081
.053
0
.021
.045
.032
1.000 1..000
Total Activity
(LTOs/year) 252,755 187,880
It is immediately evident that there is a large reduction in totfil
activity (25.7%) as a result of retaining the same number of available seat'
It is not clear that this would be a workable situation from the standpoint
-------
43
of route scheduling and the implementation of a fleet mix change would
most likely result in an increase in available seats with a correspondingly
lower load factor. An analysis of the national picture would reveal the actual
impact of this strategy on activity. The impact on air quality as studied
here, therefore, represents an upper bound on the emission reduction achievable
through this procedure.
It should also be noticed that DC-8 and CV-880 aircraft are removed
from the fleet. These emissions will have a significant impact on emissions
as will be shown later.
4.6 ENGINE EMISSION STANDARDS
The final strategy studied here is the application of the federal
emission standards for aircraft. The strategy is evaluated in two ways.
First, the standards are assumed to apply to all aircraft currently using the
Atlanta airport and the fleet mix and activity level are assumed to remain at
their current situation. This will give an indication of the impact of the
standards over existing conditions. Second, the standards are applied to the
projected aircraft activity for 1990. Since the standards go into effect in
1979, it is assumed that virtually all aircraft will meet the standards by
1990. This will give an evaluation of the air quality impacts of the applica-
tion of the emission standards and of the growth in air traffic at Atlanta.
The federal emission limits are given on Table 11. Note that the T2
turbine engine class has two applicable standards, one to be in effect in 1979
and one in 1981. The 1981 standard applies only to new technology engines
which will be certified in that time frame. For the purposes of this analysis,
only the 1979 standards are used, the rationale being that a newly certified
engine would probably be fitted on to a new aircraft type. Only current
13
generation aircraft were included in the air traffic forecasts for Atlanta.
The strategy analysis, therefore, represents a conservative estimate of the
emission reductions that might be achievable through application of the
standards.
The test cycle on which the emission limits are based are given on
Table 12. To apply the standards to the modal emission rates that are used
in the AVAP model it is necessary to normalize the emission change with respect
-------
44
3
rH
03
1
P
CO
a
o
iH
to
W
P5
HM
T-*
<4-l
03
rH
U
rH
H
rj- to
0
p i i
CD i
"? ^
1 ( 1
>
< rH
rH
O
C rH
CD i
O J
»\ »\
rH r~-
rH *d-
1 C--
CO I
>1 «
^ f-~^
p p
to t/)
X! X!
-P P
to to
X) X)
rH rH
O O
0 0
0 0
oo oo
V A
0 ^ ' > '
a
H rH CNI
X> H H
JH
5
0
to
CO
0
to
CD
.a
bO
rt
CD
o
to
f 1
h
i i
rH
03
v '
to
H
0 CTl
IO CN1
i 1
00 O1
0 *
to oo
*3- vo
CNI
r~-
to
f^
i
PQ
*\
r-^
CN]
t^
i
pq
> c-i
CT> CT>
I i
U CD
Q pq
/ 4
to
CD
$
bo
c
CD / .
P<
0 0
00 rH
H ft
R iy
rH t
rH 3
03 P
p;
«d- CNI o
H OH 4J
to
H
O,
LO
rH
CTl
rH
0
CNI
«*
Pi
O
p
to
rH
o,
1
^
^
1
*
^f-
o
*
1
I ^
rH
rH
03
rH
PH
.5
w
o
rt
H
tiO
fi
a;
P^
o
P
wi
j
r-1
OH
fH
«?
H-i
s
/ ',
a»
"H
U
o"
f^
J^
1
p
*~j
r^
X!
P
to
Xi
,_4
O
O
o
rH
to
rQ
rH
S
0)
!M
03
i/)
P^-N
H CD
l± rH
".&
;/r~^.
rH
.Jqo
XI 0
JH 0
P^
to
rHXl
OrH
P.,1'
03
CTl
r^-
o>
rH
«v
rH
fn-
03
3
1
r-l
CD
P
<-H
03
to
CD
rH
tt
H
bo
PI
CD
t-rH
^_J
CD
13
+->
o
,03
"4-1
F^
,-J
TO
E
CD
o
O
-P
CD
rH
Xl
eti
(J
H
rH
&
ot
Ti
rH
-S
P
CO
Xi
&
o
rH
O
Q
xl
0
CD
P
§
e
»\
CD
H
rH
OO
cn
rH
\
rH
>s
rH
03
1
Kj
f-.
CD
P
"4-1
0}
t/)
CD^->
rH fn
^-t U>
H O
bOH
d >
CD !H
^
H rH
4n o
H
r « r"^
rt\
U>
OT3
-p
(Ti
UJ
CD ,-Q
rH
O r J
-Sri
U -H
,_j >
rH
PMP
O rrt
^Js
T34J
^-i t/)
03 CD
"c-S
ro bo
P C
r.o S
I)
-------
45
14
to the test cycle. To do this, the emissions from current engines run over
the federal test cycle are computed (in lbs/1000 Ibs thrust-hour or lbs/1000
rated hp as appropriate). An emission reduction ratio is formed by comparing
the computed emissions to the allowable emissions. This reduction ratio is then
applied to all of the modal emission rates to obtain emission factors that
are in compliance with the standards. There is an assumption in this method
which implies that, in meeting the federal limits, the emission rates from
every operating mode will be decreased by the same amount. In practice this
may not be exactly true. Engine design modifications may result in a much
lower emission rate in one mode (e.g., taxi/idle) and an unchanged emission rate
in another mode (e.g., approach). Lacking any experimental test data, the
assumption of uniform reductions is a reasonable first approximation. Table 13
gives the new emission factors and the computed emission reduction factor.
It can be seen that the standards are providing the largest reductions in
emissions of CO and hydrocarbons with somewhat smaller reductions in NOX.
TABLE 12. Test Cycle for Aircraft Emission Standards
Time in Mode
(minutes)
Mode
Taxi/ idle (out)
Takeoff
Climbout
Approach
Taxi/idle (in)
Tl, P2
19.0
0.5
2.5
4.5
7.0
T2, T3, T4
19.0
0.7
2.2
4.0
7.0
PI
12.0
0.3
5.0
6.0
4.0
4.7 OTHER STRATEGIES
There are several other emission reduction strategies, which might
be considered for airport air quality control but which were not studied.
These include remote parking of aircraft and the use of passenger transport
buses to minimize taxi time, gate hold procedures wherein aircraft are not
cleared to start engines until departure delays fall below specified times, and
increased engine speed during taxi to improve operating performance. In addi-
tion to the controls applied to aircraft, there are some strategies that could
-------
46
rt
1
H
10 -P
rH 03
O rH
u 5c
crj (U
PH K
.1*2
If)
iiH
^
S
«Sb
*s
MH
o
8
TO
E-1
^
3
0
rH
S
rt
P
M
9<
^f CNJ f^>
o to o t*- o r~
CM «^ rH VO
OO rH
rr oo cr> oo t^- o
t^ to oo LO o o
LO Cft CM ^t
CD f>- rH rt rH LO
O *! rH 00 00 tO
OO CM rH tO
rH rH
8^8^§*
CM CM
Q LO
d O
f-i OO
5 5
IS
uy QJ
cx, u
O ^J- OO O
\G ^^ O^ frO
l~~ tj- tO l-H
rH OT O tO
to CM LO r^
CM r-
01
r~- en o o
CM CM rH CTl
CM O
rH tO O **
*t 'S- CM tO
\O i 1 CM
to
VO VO LO CM
OO*3-^D *t
t*~ to *o
8^SX8
CM tO
H E-
Q
to
vO fi
Ui Hi
U _
3:
pj urr
Q o,
00 CM
OvD
«*0
rHr--
rH
^p
LOO
rHiH
r--.
CM
Tj- LO
CMrH
vO
^J" f">
Orl-
to
X
vO 1^* LO
tOCM tO
^J f"_ 1 C^i
CMrH LO
rH LO
to
t-^CM O
«* rH LO
rH tO
CM
CM tO tO
OCM LO
to LO
vO O CM
LO rH LO
LOrH
8£§*
^^
H
Q
OO
P_4
^
S
uff
CU
CM t~~ Tt
r-~. LO o
O O CM
\O CM CM
CM O CM
00
CM CM "3-
to o to
LO
tO tO rH
OO O CM
rH
OO rH OO
CM rt O
CM
8£#
r~t
H
O
rH
vO
3
e
o to o
O CM O
o LO o
rH rH
00 00
O
rH
l>- rH CM
tO rH \O
rH CTl
vO CM tO
vO rH LO
rH tO
«i- to oo
CTt LO CTi
\O rH
QUO
CM
^
|
vjD
LO
rH
3
O CM f-
oo LO o
tO rH CTl
CM *t
t*-.
rH
rH LO O
CM i-H OO
CM r-~
0
rH
rH CM O
OO CM vO
LO
f~- tO vO
tO OO rH
rH rH
8^§x
rH
CM
O
to
1
o
rH
O O
o ooo
o ooo
o too
rH rH
o r^cs]
^D ^^ *!^
O rH
vO
**
O CTl ^f
O CM r---
vO rH
CM
O CTi O
O "* rH
r>-
LO
rH
O LO tO
CTi tOO
rH
sx£
rH
D-
0
0
OO
CM
rH
10
T3
P
!
I/)
rt
H
1 ^
d?
(U
crj
to
0
i/)
if)
H
*?
H-)
g
J3
aj
T3
O
rt
QJ
C
H
c
0
H
1
8
M
c
o
H
t/1
H
0^
1
H
g
O
T3
O
to
ctf
-------
47
be applied to other airport sources. Minimizing motor vehicle traffic through
the use of a mass-transit access system, emission controls on ground service
vehicles, and modifications to the fuel storage and handling routines might be
possible options.
For some airports, induced commercial and industrial development in
the airport vicinity may play a contributing role to air quality degradation.
Land use controls, which in most cases are necessary to minimize noise impacts,
may provide some relief from concentrated air pollutant emission densities
also. This is discussed in more detail in Section 8.0.
-------
48
5.0 STRATEGY IMPACT ON AIRPORT AIR QUALITY
This section will deal with the effectiveness of each of the strate-
gies on air quality in the airport proper. In using the AVAP model to perform
these assessments, the validation results and the caveats discussed in Section
3.0 must be kept in mind.
5.1 EMISSION PATTERN
Table 14 gives the emissions for the Atlanta airport and its environs
under baseline conditions. Environ emissions included all point sources in the
ten-county area surrounding the airport and area sources extending 20 km from
the airport boundary. A more detailed description of the environ inventory is
given in Sections 6.0 and 7.0.
TABLE 14. Annual Emissions for Atlanta Airport
and Environs Under Baseline Conditions
Annual Emissions
(metric tons/yr)
Source
Aircraft
Ground Service Vehicles
Access Traffic
Engine Test
Fuel Storage
Space Heating
Airport (non-aircraft)
Total Airport
0
Environs
CO
4,959
1,626
1,870
130
0
6
3,632
8,591
264,000
HC
2,415
224
430
51
375
2
1,082
3,497
77,000
NOX
2,072
57
212
284
0
29
582
2,654
65,700
«3
Includes all point sources in Fulton, Clayton, DeKalb, Fayette, Henry,
Spalding, Gwinett, Rockdale, Cobb, and Coweta Counties and area sources
to a distance of 20 km from the airport boundaries.
Aircraft are responsible for about 581 of the CO, 69% of the HC, and
78% of the NOX at the Atlanta airport. The entire airport accounts for 3% of
the regional CO emissions, 4.5% of the HC, and 4% of the NOx- The indications
are that the control of aircraft emissions will have a small impact on regional
-------
49
emission loads. It is important to emphasize that any controls applied to air-
craft have their impact diminished by the amount of the relative contribution
of aircraft to the total emission rate. In the case of the Atlanta airport,
for example, any reduction in aircraft CO emissions becomes only 581 as large
in total airport emission reduction and 1.741 (58% x 3%) as large for regional
emission reduction. The expected impact of a strategy, therefore, must be put
into perspective with the total emission picture. Table 15 compares the emis-
sion reduction impact of each strategy in terms of the relative change in air-
craft and total airport emissions.
It is obvious from Table 15 that the application of engine emission
standards has the greatest impact on reducing emissions. In addition to pro-
viding large reductions in CD and HC emission rates, the standards provide sub-
stantial reductions in NOX that cannot be matched by the other control options.
Aircraft towing and the fleet mix change are next in order of achievable emis-
sion reductions, but the fleet mix option has the drawback of significantly
increasing NOX emissions. The engine shutdown and capacity control strategies
provide only small reductions and the indications are that these procedures
may be justified only in regions requiring maximum emission control from all
sources.
It is also evident from Table 15 that the best strategy provides,
for the entire airport, a little more than a one-third reduction in CO emissions
and about a one-half reduction in HC and NOX emissions, corresponding to 62%,
71%, and 45% reductions in aircraft emissions of these pollutants, respectively.
For the capacity control and fleet mix control techniques there is a synergis-
tic effect since changes in the aircraft activity pattern also change the
ground service vehicle requirements. Reductions in aircraft emissions by re-
ducing the total aircraft activity has an added benefit through reduction in
ground service vehicle emissions.
Table 16 summarizes the fractional contribution of each mode of
aircraft operation to the emission rate. Towing, fleet mix control, and engine
emission standards substantially alter the distribution of CO and HC emissions
among the modes. For towing, there is a marked reduction in taxi/idle emissions
since aircraft are not operating engines in this mode. Fleet mix changes result
in different aircraft operating procedures and hence different modal characteris-
tics. Engine emission standards provide an across-the-board emission reduction
-------
50
re
g
H
P
rK
TO
i
0)
rH
S*
(D
1 \
T-*
re
rH
P
CO
H
'a
o
10
I
p
a
^
m
re
rH
z
'$
LO
rH
I
r^
if
p «
MH o
re -H
rH
U t/)
rH
re o o
i; H p<
0 Pr
.0 -S £
& 41
Jre
rH
o
rH
o\° -H <
W
41 g
re -H
rH 01
O W
5 (S
&
» *«
<* -D- (XI
S i
a §1 g5
id
+J rH tL, 4-1 rH tL, g
H Oi-J -H O i-J
O rH O rH -P
re -P ov° re +-> <>p 0
PL, C LO p< g o 0
re o vo re o r^. rH
U C_3 v ' O O v ' PH
o
rH
*sf
00
3-
rt
1
10
4-
^*J
rH
rH
Tt
0
L/5
1
rH
rH
h-
i
oo
CTl
vd
cn
vO
to
i
<*
(XI
VO
l
^-
vO
oo
»\
rH
Engine
Emission
Standards
rH
^
in
-p
o
H
rH
4J
in
c
O
H
in
in
u
rH
.«
-------
51
TABLE 16. Aircraft and Ground Service Emissions by Operational Mode
Mode
Start up
Taxi out
Takeoff
Climb out
Approach
Landing
Taxi in
Shutdown
APU
Grnd Serv.
Total a
Emissions
(metric
tons/yr)
Start up
Taxi out
Takeoff
Climb out
Approach
Landing
Taxi in
Shutdown
APU
Grnd Serv.
Fuel Refill.
Total a
Emissions
(metric
tons/yr)
Start up
Taxi out
Takeoff
Climb out
Approach
Landing
Taxi in
Shutdown
APU
Grnd Serv.
Total
Emissions
(metric
tons/yr)
Baseline
13.5
23.7
1.4
4.7
9.0
2.4
15.9
2.1
2.6
24.7
6,585
22.3
27.2
0.2
0.4
2.0
1.9
18.8
3.1
0.3
8.5
15.4
2,639
1.3
3.5
21.9
32.2
25.2
7.1
2.3
0.2
3.6
2.7
2,129
Engine
Shutdown
14.0
24.7
1.4
4.9
9.4
2.5
12.9
1.7
2.7
25.8
6,329
23.9
29.1
0.2
0.5
2.1
2.0
14.0
2.5
0.2
9.1
16.4
2,469
1.3
3.5
21.9
32.2
25.1
7.1
2.5
0.2
3.6
2.6
2,131
Towing
\ of
21.1
3.2
2.2
7.4
14.2
3.7
2.1
3.3
4.1
38.8
4,200
% of
40.4
1.4
0.3
0.8
3.6
3.4
1.0
5.6
0.5
15.3
27.8
1,459
% of
1.4
0.5
23.1
34.0
26.5
7.5
0.3
0.2
3.8
2.7
2,019
Capacity Capacity
Control, Control,
(651 LFb) (70% LFb)
CO Emissions
13.5
23.7
1.4
4.7
9.0
2.4
15.9
2.1
2.6
24.7
6,289
HC Emissions
22.3
27.2
0.2
0.4
2.0
1.9
18.8
3.1
0.3
8.5
15.4
2,519
NOX Emissions
1.3
3.5
21.9
32.2
25.1
7.1
2.3
0.2
3.6
2.7
2,033
13.5
23.5
1.4
4.7
9.0
2.4
15.6
2.1
2.7
25.0
5,771
22.3
27.1
0.2
0.4
1.9
1.9
18.6
3.1
0.3
8.5
15.5
2,327
1.3
3.6
22.0
32.3
24.8
7.2
2.4
0.2
3.6
2.7
1,851
Fleet
Mix
24.2
23.5
0.4
1.2
6.3
2.2
17.2
1.1
3.3
33.6
4,529
10.7
21.7
0.2
0.4
2.0
1.8
15.9
1.0
0.5
16.4
29.4
1,275
1.2
2.7
20.5
30.7
30.1
8.3
2.0
0.1
2.4
1.9
2,722
Engine
Emission
Standards
5.6
14.0
1.9
7.0
8.0
1.9
9.1
1.1
5.0
46.6
3,491
7.1
12.2
0.1
0.3
1.1
0.9
8.4
0.9
0.8
24.3
44.1
922
1.2
3.1
20.0
34.0
20.2
8.2
2.0
0.2
6.3
4.7
1,199
T _1._J _-I f^ A Tit I J 'L_?_1
^Includes aircraft, APU, ground service vehicles.
"Load factor.
-------
52
in all modes and elevate the ground service vehicle emissions to an over-
whelming position. The relatively small change in engine shutdown modal dis-
tribution is a result of the limited application of the strategy as practiced
at the Atlanta airport.
Hie implication of this review is that towing, fleet mix control,
and engine emission standards will, in addition to lowering the overall CO and
HC emission rate, alter the spatial emission pattern. The other control op-
tions will lower emissions but will maintain the same general distribution.
This is significant to the determination of the air quality impacts in the
immediate vicinity of the airport. None of the control options significantly
alters the NOX modal distribution. This is a result of the fact that these
emissions occur primarily in the takeoff, climbout and approach modes. With
the exception of the engine emission standards that provide an overall NOX
emission reduction, none of the strategies addresses itself to this problem.
Table 17 indicates the relative contribution of each aircraft class
to the overall emissions. Aircraft, auxiliary power unit (APU), and ground
service equipment emissions have been included in the totals to demonstrate
the added emission reductions resulting from ground service vehicle activity
changes induced by aircraft activity changes. Comparison of this table to
Table 5 yields some interesting observations. The DC-8 and CV-880 aircraft
are contributing more to the total CO and HC emissions than their activity
level would indicate. They account for about 12% of the activity but 33.9%
of the CO and 62.4% of the HC under baseline conditions. Based on the obser-
vations at the Atlanta airport, one of the biggest problems with these aircraft
is the exceptionally long time required to start the engines at the gate. Since
these aircraft are not equipped with auxiliary power units, they must remain
in the gate position until all engines are running. The time from first en-
gine start to the start of forward roll out of the ramp area was measured at
an average of almost 7 minutes as compared with 1-2 minutes for all other
aircraft, with the exception of the B-747. Only the application of engine
emission standards alleviates the problem (at least within the limits of the
assumption of uniform emission reductions among all operating modes). Fleet
mix control removes these aircraft altogether but generates a similar problem
with the jumbo jets which make up 24.4% of the new activity level but contri-
bute 51.8% of the CO and 54.5% of the HC.
-------
53
in
rH
U
*$
JH
U
JH
5!
0
c
O
H
I/)
3
t§
a>
rH
O
'f-l
^
1
5
§
T)
£
rt
J^
O
*
^^.
a
I
H
e-S
8 fi
CD'H CO
.358*8
OJ>H TO
M
CD
CD K
X. / *
<->rH tit
fl 8 J
O M
CO 4-> <*»
^N ^""^
4->rH PH
«H O i-J
O r<
cd 4-* <*°
utS ^2/
M
H
g
H
!
5 tj
££
.5
rH
CD
!/)
cd cd
t-i in
H cd
rj rH
cd
in
g
H
in
d
w
8
q_l
O
<^o
to r- LO o LO
LO LO to LO o
rH LO fsl
00 O rj- to LO
rH 0 0 tO t
LO *
(sj tO t-- 0, 0)
^- ^d- rt to CM
tO ^J- rH
^t CTi f-J OO l~~
. . . .
tO <^* rH
to * r^ \o o
. . .
^J- O LO *£> tO
tO ^ rH
r~- CTI to to oo
** Pi Tt s
^a- cr> CM oo i^
5t tO ^- tO tO
tO T^- rH
rH /*~^
0 <4H 0
rH Cd '*
I in r< 1
j -P o 2 C
!/) CD r< O
> 4-> . v >-3 -H « -H
O CDO , >^-^
rH*~"3OO CDt^ rH CdG
1 OO MCM CD ' "H O
+->Q D0i> roi C>-i<;(/)
CD G U DS PQ S «H
o^r 100 3oi 4Jto JH >
o t OO 1 -iH I rH t Ci) 4-*
^©^s^s^e/as
o
o
o
rH
O
O
o
rH
O
0
0
i-H
O
O
O
rH
O
o
o
rH
0
O
o
rH
0
O
O
rH
cd
O
rH
[/)
in
rf
w
a
14H
O
*»
vO to r-J ^O to
OO tO rH »S- (M
CM \O
LO O OO LO
rj- O O tO CM
LO «*
CS1 t~^ OCM Ol
tO (NI rHCM O
\o to
CM ^t CT) CM tO
tO CM OCM rH
>o to
r- t^ ooo oo
to to oo to o
LO tO
^ rH O> tO tO
tO rH rHCM i 1
\D tO
CM ^- CTlCM to
tO CM O CM i 1
\o to
4n
cd
in r<
MUG
in CD ft O
4-> TH -H
CD <, +->
>-) CD cd
bOCD -H
in CD C M >
lg>lg g
^ J3 ^Lo $
0
o
o
rH
O
O
O
rH
0
O
o
rH
0
O
O
rH
O
O
O
rH
O
o'
O
rH
O
O
0
rH
cd
G"
o
H
(/)
H
tS
_
g
m
o
«*>
LO \o en LO LO
vO vO LO tO f^
rH LO rH
voo to »* r^
rHO LO CM O
vO tO
tO^f tO LO LO
t^LO tO to O
rH t^
I CM OO *^ C7^
OOLO rH tO O
rH r--
OLO Ol OO OO
LO rH CM O
rH l-~
t^* CM OO ^^ C7^
OOLO rH tO O
rH r~-
t-^ CM OO rt C7>
OOLO rH tOO
rH t-»
4J
CO
OT (-<
*-> U C
in CD )-i 5
(-> !-3 -H-H
^ CD*5 to
00 CD-H
in CD C oc ^
O 1 S -P fl
^ J ^L^cS
o
o
o
rH
O
CD
O
rH
O
O
O
o
o
o
rH
O
O
O
rH
O
O
o
rH
O
O
O
rH
CD
"3
H
1
8
CD
(/I
rrj
1
5
CO
B
'So
I/I
1
rH
cd
-------
54
Figure 8 shows the impact of capacity control on emissions. The
change is linear and the emissions decrease at a slightly higher rate (12.41
for CO. 11.8% for HC, and 13.11 for NO^) than the activity decreases (10.8%).
This is due to the aforementioned reduction in ground service vehicle emissions
accompanying the aircraft activity decline.
Table 18 gives the normalized emission rates (aircraft and ground
service vehicles) for the Atlanta airport for each control strategy. Since
the number of enplaned passengers is constant in all strategies, the emissions-
per-passenger reflect the same changes as were observed for the total emission
reduction on Table 15. The number of LTO cycles, however, varies with the
capacity control and fleet mix strategy. The results are that (1) capacity
control produces virtually no change in the per-LTO emission rate and (2) the
fleet mix control produces a smaller relative change in the per-LTO CO and
HC emission rates than in the total emissions and a larger relative change
in the per-LTO NO^- emission rate. This implies that fleet mix changes bring
in aircraft with smaller CO and HC emission rates and that emissions are de-
creased further due to the reduced number of flights required to provide the
same number of available seats. In contrast, the mix changes bring in aircraft
with larger NOx emission rates, but these are partially offset by the lower
activity level.
There is a temptation to use the normalized emission rates on
Table 18 to estimate emissions at other airports for the same strategies.
This may be valid as a first approximation but should be treated with utmost
care in attempting to select an appropriate control option for another airport.
More detailed study of the local conditions may drastically change the rela-
tive merits of each strategy.
5.2 AIR QUALITY IMPACTS
5.2.1 Normal Conditions
In performing dispersion calculations with the short-term version
of the AYAP model, it is necessary to specify distinct meteorological condi-
tions. Choice of representative parameters for the strategy analysis was
based on two criteria. First, the meteorological conditions chosen had to
occur with sufficient frequency in the Atlanta area to be representative of
-------
55
8
o
o>
ro
O
CO
CO
CO
LU
0
60
Fig. 8.
CO
HC
62
70
64 66 68
LOAD FACTOR, %
Effect of Passenger Load Factor on Emissions
72
-------
56
10
CD
£
£
O
H
if)
in
rj
fi
CD
O
pj^j
0)
£>
CD
O
r<
CO
tO
TJ
s
o
ft
tJ
3
4-1
MH
a!
ft
O
ft
CO
N
H
rH
?3
o
oo
rH
a
H
si!
CD-H rt
P! 10 "TD
H (/> p!
bO-H c3
4_>
<
^ s
X /-'.
PiH P-c
H O i-3
0 ft
Co 4-* o\°
ft Pi O
c3cS ^
^"v /*"">
H O -3
O ft
CS +-> o\°
ft Pi LO
cd o vo
uc_> ^-^
DO
fH
g
O
H
g
§
CO O
.S3
bO ^3
p^ r^
ffl en
rt
rH
!-H
CD
i
C^
1 _1
_J
o
H
W
t/1
'1
rH
O>
CM
[^^
to
,«4
oo
^j-
CM
LO
O
LO
to
c*-^.
CM
LO
o>
LO
8
ft
CO
bo
O
y^
t/i
Co
ft
8
rH
S
r?
f-^.
[
0
VO
O
rH
T^
rH
O
i 1
CM
CM
CM
rH
vD
rH
CM
O
CM
CM
^
ft
CD
P?
CD
(/)
(/)
w
p^
Q>
g
i i
&
CD
rJ
0
o
rH
^
CM
Cv]
^^
LO
rH
CT)
vO
rH
f-^.
f^.
i-H
OO
f-^.
rH
f^.
p-*^
rH
X
ft
CD
bO
p)
CO
10
10
cd
ft
0
c3
rH
CO
&
rH
OO
to
rH
rH
rH
^^
CM
oo
LO
LO
CM
rH
O
vO
CM
CM
VO
^O
rH
^^
0
LO
CM
LO
O
vO
CM
8
p
H-5
^
LO ^f
*
to **
01 0)
r-- *
»
v^5 ^d"
rH
CM rH
tO CM
o oo
! 1
CM rH
^^ ^^
o oo
rH
t"*~ Oi
t^- Oi
*
LO C--
t~~ to
^ "t
CTi 00
Tt tO
^f ^c^
o oo
rH
_x
U <3
Q P
F1 H
x^ ^^^
^^» ^^.
bo bo
-------
57
likely situations. Second, two very different air quality patterns can be
expected when the wind blows from the north or from the south. Northerly winds
carry the emissions from the city of Atlanta across the airport, while southerly
winds carry little in the way of background emissions due to the relatively
undeveloped area south of the airport (see map of Fig. 1). The chosen meteoro-
logical patterns should include at least one case representative of both wind
directions.
Typical seasonal meteorological conditions for Atlanta were deter-
mined by looking at climatological records for the months of January, April,
July, and October. The Decennial Census of United States Climate-Summary of
Hourly Observations for 1951-60 was used to determine wind speed, wind direc-
tion, and temperature. Other data ' ' ' were used to determine mixing
depths and stability class. The conditions for July and October were chosen
for the analysis since they best satisfied the two criteria. They are tabulated
on Table 19 and are referred to as Summer and Fall respectively. (The wind
directions for January and April were from 291° and 254°, respectively, and
hence would not have provided a significantly different analysis than the July
conditions.) Under the summer conditions, aircraft arrive and depart to the
west and under fall conditions, to the east. The hour from 11:00-12:00 AM was
used in the one-hour average calculations. It is the busiest air traffic hour
of the day and its analysis represents maximum strategy impact.
TABLE 19. Typical Meteorological Conditions for Atlanta
Wind Direct iona(deg)
Wind Speed (m/sec)
Average Temperature (°F)
Stability Classb
Mid -Day
Maximum Temperature (°F)
Mixing Depth (m)
Night -Time
Minimum Temperature (°F)
Mixing Depth (m)
Summer
(July)
228
3.5
78.7
4
89
1640
68
100
Fall
(October)
17
4.0
62.4
4
72
910
52
100
Northerly wind is 0°.
Pasquill stability classification.
-------
58
Figures 9a.-f., 10a.-f., and lla.-f. show the calculated isopleths
for CO, HC, and NC^, respectively, for baseline conditions and each of the five
strategies studied. The capacity control strategy is represented by the 701
load factor only. In addition to the graphical display, pollutant concentra-
tions at various airport activity sites are tabulated on Tables 20, 21, and 22
for CO, HC, and NO^, respectively. These sites were chosen as being representa-
tive of places where airport employees or passengers and visitors might be
expected to spend significant amounts of time. Most of the activity sites are
north of runway 8/26 (the northernmost), with the exception of the Delta Jet
Base and the central fire station. The concentration at each site is obtained
by averaging the concentrations calculated at several receptor locations in the
vicinity of the site.
CO Analysis
The baseline CO isopleths of Fig. 9a. and Table 20 show the highest
CO concentrations to be in the vicinity immediately downwind of the terminal
for both summer and fall conditions. This is as expected since the terminal
concentrates emissions from aircraft, ground service vehicles, and access
traffic in one area. In addition, in summer there is a small "hot spot" at
the northeast end of runway 8/26 and in fall it is at the southwest end. This
is probably a result of takeoff queuing and the emissions associated with take-
off and climbout paths being blown back down to the ground. That similar
peaks do not occur near the southern runways may be the result of a lower over-
all concentration at the site or the result of a lack of resolution in the
model's receptor network.
Under summer conditions there is also a high concentration zone
around the remote parking facilities northeast of the terminal, as a result
of the terminal emissions being transported over the parking lot, which is
an additional significant emission source. The combination creates a CO level
comparable to that in the vicinity of the terminal itself.
The isopleths and Table 20 show that nowhere is the National Ambient
Air Quality Standard for CO being exceeded. In fact, these values are well
below the more stringent eight-hour standard of 10 mg/m3. In this respect
the model results are consistent with the GEOMET observations during the field
test, which also indicated no violations.
-------
59
ALL CONCENTRATIONS IN yG/M3, 1-HOUR AVERAGE
2200.
SUMMER
FALL
Fig. 9a. Airport CO Concentrations for Baseline Conditions
-------
60
ALL CONCENTRATIONS IN pG/M3, 1-HOUR AVERAGE
SUMMER
FALL
Fig. 9b. Airport CO Concentrations for Engine Shutdown Strategy
-------
61
ALL CONCENTRATIONS IN PG/M3, 1-HOUR AVERAGE
200
SUMMER
FALL
Fig. 9c. Airport CO Concentrations for Towing Strategy
-------
62
ALL CONCENTRATIONS IN yG/M3, 1-HOUR AVERAGE
SUMMER
FALL
Fig. 9d. Airport CO Concentrations for Capacity Control Strategy
-------
63
ALL CONCENTRATIONS IN yG/M3, 1-HOUR AVERAGE
2200
f\ 200
SUMMER
500
FALL
Fig. 9e. Airport 00 Concentrations for Fleet Mix Strategy
-------
64
ALL CONCENTRATIONS IN yG/M3, 1-HOUR AVERAGE
200
SUMMER
FALL
Fig. 9f. Airport CD Concentrations for Engine Emission Standards
-------
65
ALL CONCENTRATIONS IN yG/M3, 1-HOUR AVERAGE
SUMMER
/300 (
FALL
Fig. 10a. Airport HC Concentrations for Baseline Conditions
-------
66
ALL CONCENTRATIONS IN u.G/M3,1-HOUR AVERAGE
SUMMER
FALL
Fig. lOb. Airport HC Concentrations for Engine Shutdown Strategy
-------
67
ALL CONCENTRATIONS IN yG/M3, 1-HOUR AVERAGE
MIND
DIRECTION
200
300
100
SUMMER
200
FALL
-------
68
ALL CONCENTRATIONS IN uG/M3, 1-HOUR AVERAGE
SUMMER
FALL
Fig. lOd. Airport HC Concentrations for Capacity Control Strategy
-------
69
ALL CONCENTRATIONS IN yG/M3, 1-HOUR AVERAGE
WIND
DIRECTION
SUMMER
FALL
Fig. lOe. Airport HC Concentrations for Fleet Mix Strategy
-------
70
ALL CONCENTRATIONS IN yG/M3, 1-HOUR AVERAGE
SUMMER
FALL
Fig. lOf. Airport HC Concentrations for Engine Emission Standards
-------
71
ALL CONCENTRATIONS IN yG/M3, 1-HOUR AVERAGE
SUMMER
FALL
Fig. Ha. Airport NO Concentrations for Baseline Conditions
-------
72
ALL CONCENTRATIONS IN yG/M3, 1-HOUR AVERAGE
WIND
DIRECTION
SUMMER
FALL
Fig. lib. Airport NO Concentrations for Engine Shutdown Strategy
-------
73
ALL CONCENTRATIONS IN yG/M3, 1-HOUR AVERAGE
MIND
DIRECTION
SUMMER
FALL
Fig. lie. Airport NO Concentrations for Towing Strategy
.A.
-------
74
ALL CONCENTRATIONS IN L.G/M3, 1-HOUR AVERAGE
SUMMER
FALL
Fig. lid. Airport NO Concentrations for Capacity Control Strategy
-------
75
ALL CONCENTRATIONS IN yG/M3, 1-HOUR AVERAGE
MIND
DIRECTION
SUMMER
Fig. lie. Airport NO Concentrations for Fleet Mix Strategy
JC
-------
76
ALL CONCENTRATIONS IN uG/M3, 1-HOUR AVERAGE
SUMMER
FALL
Fig. llf. Airport NO Concentrations for Engine Emission Standards
A.
-------
77
rt
o
H
_ 1?
C
8
j_j
rri
P
o
2;
in
O
HH
fi
o
rH
4-1
P
6
u
pj
5
o
0
P
(H
O
H
^
O
f-J
W
?n
^*
E-*
I1
eW> ra
6
c-3
O h
'w-1
^
X
U-
f
O LO
Is- en
to oo
LO O4
r-- \o
SS
LO r~-
oo o
rH
I-- 00
og o
O CD
O 04
r- i~-
og og
O 0
\O fxi
*j- en
oo ^
og og
Q, (H rH
ji TO
c2 1 u«
MH
cO
ri
<
§
1
0 \0
\O fxi
og i
og 10
rH tO
og LO
en og
co o
t-H i
LO CXI
LO OO
LO tO
og LO
co to
oo o
r-. ^t
P- LO
oo to
og LO
CO Is-
rH O
to +
O r-
Tfr 0
00 CO
O 0
cn r-
cxi og
rH tO
tO LO
O 0
LO r-
rH tO
to LO
r4 rH
i0*
%
P&
«
t "»
OO Oi
0 rH
O O
' '
O> 00
"3- 00
OO O>
t^l \o
CD O
0 O
Ol CM
*T 01
OO Ol
fO \o
o r^
o o
CTi LO
oo Ch
to vo
0 0
0 0
cn **
»» o
OO CT)
^ vO
o ^r
LO 0>
00 Ol
^ 1-. r-H
(0 ^ f-H
§1"'
g
H
4-*
.3
^
rH
CO
FH
00
^- o
og
O4 tO
r- rH
to \o
cn o
rHO
rH
\O og
rH rH
CO \O
cn o
LO O
cxi 04
0 rH
Cxi \O
cn \o
00 0
to
CO (XI
t-- rH
O4 O
to o
cn og
O rH
cn o
CO CXI
Is- rH
cn o
(H rH
ty I-H
I ^
eO
<
a
CO
tO rH
O CO
LO 1
O4 CO
GO cn
CO rH
rH *
co cn
\o to
04 i
Is- O
^o cn
r- to
04 *$
VOO
t-H rH
rH I
tO 04
^ cn
to rr
tO Tt
rj- GO
ST
to og
tO rH
Cxi O4
i ( **
0 0
og og
^t LO
OO r-
to ^t
(MO
OO vO
r- LO
IO -«3-
V-i rH
O i-H
c i tu
H CO
H
t/3
z
H
a.
rH
CO
i
u
««* cn
cn LO
to i
0 0
to o
cn LO
04 tO
\O t^t
to to
rH «*
O CD
LO CO
en to
rH rH
*± og
rH Is-
rH CO
rH 1
O 0
LO Tf
rH tO
to «*
TJ K)
cn I-H
t^- to
O 0
O O4
O **
LO rH
I-H og
\O (x»
og o
o o
^O LO
og LO
r-- r-
TJ- to
0 0
^ 04
LO \O
co r-
«* to
/ s/ ,
tO LO
LO ^t
i-H rH
M rH
O rH
r* E CO
O E U-
4-> 3
S*w
a:
4-1
in
1
a>
a
1
to
r^
rH
"e
DC
3.
c
l/l
c
o
H
2
c
o
(J
rH
-------
78
rt
I
o
H
P
I
§
8
u
x
+j
o
*-> i-H tL,
rt O J
U !-
CO 4-1 d\°
O.C O
co o r-.
CJ U *'
.S3
a
cno oo ^t ro rs) ooto oo ooo cn cn r~- o
cno toto r--.ro CDO oo r-- o torH «* cn
I LOrsl^J-rH II tO [-- rH LO I
O rs] rH rH O LO O O LO LO rs] ^J- >O O O O
vO t-- I^O LOtO Cn O O -* CO rH O rsi CD ^ ^o I-H o o ^ oo
^j-\o *^-cn LOCO -d-rsi LOCD tocn VOLO LOLO
^J-rs)COtO rH rHCs) rHLOLO
rH
t-^O tOCD rslOO LOrH Ot>- COO LOlO LO^J-
rH o cn LO \o rsi ^- rH o o rsi o ^ rH cn \o
rsll LOtO ^-l II I ^J- COrH LOrs)
\oo LOCD vor-^ rsjr-- men to-* *!*LO OrH
cor-- rsjto LOCO r-~LO oto rHrH COLO cno
Td-rs]LO-* rH rHrH fI rH \O
rH
TJO OO CDr- OO OO OO LO«J- '£)rO
rHO tOrs] rH-«t OO OO OO rsttO tOO
rH rsi o ^~ LO r^- ^ o LO \o o ** r-) x± o to
f^ t-- «*rO ^rH Cnt>- O^J- ^trH **OO O^f
OOO rHO COCn ^trH LOO rHCn l~*u? *& &*
0)
?
OOO Ttrs] -stO LO\O vO^T rHO O CM CO
LO r>- t-~ r--- LO o cn r-*- o *^ Tt* rH r--. ^3- cn r-^
cn o o rH oo cn ^ rH to o to cn «-H vo to o^
LOrg-^-r-. rH rHtO rHrHr~-00
E
DO
a
,2
.s
(U
4-1
t/1
,3
o
oo
3
<0
CO
2
H
UH
I
§
-------
79
rt
3
2
p
H
"d
r J
r"1
rt
^.4
^
1
S
0
H
P
2
i
c
0
u
fi
6
X
is^
^
o
&1
H
<
'
LL]
r«J
1
Sj
cO
6
l/l
o *2
't/l "TJ
11
0)
^ c3
6
w
(L) -rt
-i S
u,
DO
"I
X ^
+-J rH U,
HO]
O J-«
CO 4-J efi
ago
LO
c
H
o
i
c
o
H
to
8
00 ro^t 0>rO 00^ ON
rH o cn to r-- o rH o o o
rH II rsj 1 + >
rH MH ^tr-4 OOrH r-- ^t (NJOO
cnr-~ cnoo oor-- ooto TtrH
rH i 1 rH CN] rH
OrH ^O vf CDfO CDLO OO
fxiO fMCO ^OrH OC OO
i V; ^
^" (Nj CTi r~- ^" rxl *O O r\l LO
OOr^ rHLO OCO C^^T ^rH
\o ^D o I**- oo ^o LO oo cn to
^-4 rH CSl rH rH
OOO O«* \Di-H Org OO
LO O Cn LO 'O O O CD O CD
(N| rH O CTl rH fNl vO *T (N| LO
oo-o "^to r^vc LOOC cnto
rH rH t 1 rsj rH
CDrH tOtO -«*rH r-JOO OO
rHO tOO OO OO OO
to . LO rg i + "i
oo cnr^ to^r Lncn (MLO
rxir- ooo or-- r-^-r-j Tfrt
rH rH rH rH
<^0 rs,_ CO 00 00
OC2 CDCD CiO CDC; OO
OrH rtrv, o to 00 <^l LO
rH rH rH Csl rH
tO r t r^-rj- LOtO OO (NJLO
rH rH rH (NJ _~f
rHrH &r-.rH r-.rH r*~- (-UrH
5 I*1* ^1^ I""" I^* ll"1*
OO LW "~
C CO C
H r- O
^ U 0> JH --H
r- rH t/3 C3 4-»
CO 'H aj DC CO
D- ^ fl5 C -H
rH rH O
S S ^ E 13
H -H CO QJ »-.
6 6 +J *-* (U
C p rH
CO
CO -H
Q^ LL,
rH
u
a:
1
2
(U
00
a
^
>
rt
£
"e
DO
3.
c
iH
c
o
H
4-1
cO
rH
M
c
§
8
rH
5
oT
-------
80
Comparison of the isopleths for engine shutdown (Fig. s>b.)» and
capacity control (Fig. 9d.) to the baseline conditions show virtually no
change. Likewise, Table 20 shows only small changes at the activity sites,
with the central fire station showing a maximum of an 11.6% decrease as the
result of the capacity control option. The towing, fleet mix,, and engine
emission standards (Figs. 9c., e., f., respectively) showed marked alteration
in the air quality patterns. All reduce the area contained within the high
concentration isopleths as well as lower the overall concentration levels.
Under fall conditions, and to a lesser extent under summer conditions, there
is a persistent set of isopleths at the 500 yg/m3 level that appears particu-
larly insensitive to the control strategy applied. These levels are being
generated primarily by the road traffic on the highways surrounding the airport.
It is significant to note the difference between the aircraft CO
emission reductions given on Table 15 and the actually realized air quality
improvements given on Table 20. The engine shutdown, capacity control, and
engine emission standards options show maximum air quality improvements that
are somewhat less than the aircraft emission reductions. Towing and fleet mix
controls show air quality improvements that are greater than the aircraft
emission reductions. The reasons for this have been alluded to previously.
Towing drastically changes the spatial emission pattern as well as reduces
overall emissions. By removing the engine startup and taxi/idle emissions
from the terminal area, this strategy prevents a concentration of emission
sources. Fleet mix controls provide the added benefit of reduced ground service
vehicle requirements, hence achieving a somewhat higher level of air
quality improvement. The other three strategies do not change the emission
pattern enough to gain any additional air quality benefits other than the over-
all emission reduction.
The engine shutdown strategy as practiced during the field test is
especially disappointing and provides only a little more than 3% improvement
in air quality. Given this small difference it is not surprising that the CO
field observations were not able to detect any statistically significant change.
HC Analysis
The HC isopleths of Figs. lOa.-f. and Table 21 show basically the
same behavior as the CO data. Highest concentrations are immediately down-
-------
81
wind of the terminal. There is a "hot spot" northeast of runway 8/26 in the
sunnier and southwest of it in fall corresponding to queuing and takeoff emis-
sions. There is another hot spot corresponding to emissions from the fuel
farms just north of 8/26 and east of the terminal. This is readily apparent
in Figs. 10.e. and f. As with CD, high HC concentrations are calculated in the
remote parking facility during summer conditions.
It is evident from looking at the figures that a potential exists
for violation of the National Ambient Air Quality Standard for hydrocarbons.
The calculated concentrations are far in excess of the allowable concentration
of 160 yg/m3. At this point it is not possible to say that the standard is
being violated for two reasons. First, the standard is based on a three-hour
average as opposed to the one-hour average used here. The persistence of the
given emission pattern and meteorological conditions for three consecutive
hours would, in fact, indicate a violation. Second, the standard is based on
the concentration measured for the hours 6-9 AM while these calculations
were performed for 11-12 AM. (It will be shown later that the three-hour
average concentration calculated for 6-9 AM does, in fact, exceed the stan-
dard of 160 yg/m3.) Despite these two reservations, it is significant to note
that none of the control strategies is completely successful in reducing the
concentrations below the standards. Table 21 shows that the towing, fleet mix,
and engine emission standards are the most effective strategies in reducing
concentrations at the airport activity sites, although four of the sites are
still in excess of the 160 yg/m3 standard for all of the options. Note also
from Table 14 that aircraft are responsible for about 2/3 of the hydrocarbon
emissions. Since these control options do not result in bringing the HC con-
centration even close to the standard, controls placed on other airport emission
sources would probably not result in attainment of the standard even when coupled
with the aircraft controls.
One final point should be made about the use of the AVAP model for
hydrocarbon calculations. The model does not account for photochemical reac-
tions between hydrocarbons and other pollutants. The state of the art of
reactive pollutant modeling has not yet advanced to the point of being able
to predict microscale dispersion patterns, nor is the macroscale predictive capa-
bility very good. Therefore, the use of a nonreactive dispersion model to
simulate reactive pollutants can give useful insights providing some caveats
are kept in mind. The calculated HC concentrations must be viewed only as an
-------
82
indicator of potential problem areas and not as absolute values., The longer
the time scale and the wider the area covered by the calculation, the less
valid the model will become because of the reaction rates. In this regard,
the one-hour average concentration calculated here may be more meaningful than
the three-hour average, which will be given later,, in terms of predicted HC
concentrations that might actually be observed. This exercise has its greatest
value if the results can be confined to qualitative interpretation. Thus,
it can be said that the calculations show a strong potential for violation
of the National Ambient Air Quality Standards for hydrocarbons and none of
the studied control strategies appears to be sufficient by itself to assure
compliance. Only a first approximation to the relative effectiveness of the
strategies could be achieved through the use of this modeling technique.
Analysis
Examination of Fig. lla.-f. shows a different air quality pattern
for NOx than for CO and HC. Since NOX emissions occur primarily in the takeoff,
climbout, approach, and landing modes, there are areas of high concentration
ionmediately downwind of the duty runways. The terminal area is another high
NOx concentration zone due to the large number of sources (i.e. aircraft and
ground service vehicles), even though the individual source emission rates are
not at their maximum in this area. It is also apparent that there is a sig-
nificant contribution of NOX from environ sources, primarily the roadways
surrounding the airport. There are high concentration areas that are far-
removed or upwind of any aircraft activity.
Since the National Ambient Air Quality Standard for nitrogen oxides
is based on an annual average, it is not possible to compare these short-
term calculations directly to the standard, except to say that several locations
show calculated concentrations above the 100 yg/m3 standard for both summer
and fall conditions that could indicate potential problem areas. The annual
average calculations with the long-term model will be discussed later.
As with the other pollutants, the engine shutdown and capacity
control show little impact on air quality. Neither one changes the total
emission rate or the spatial emission pattern enough to effect any significant
air quality improvements. The towing, fleet mix control, and engine emission
standards, on the other hand, generate substantial changes in the air quality
-------
83
picture. The emission standards provide a general concentration reduction at
the runway ends but do not alleviate the terminal area problem by very much.
Towing makes an impact on terminal air quality by removing all of the air-
craft NOX emissions there, but complicates the problem at the runway ends by
adding the engine startup emissions to that vicinity. Fleet mix controls as
shown on Table 22 create additional NOX air quality problems because of the
increased emissions from the large jumbo jet aircraft that are being incor-
porated into the fleet. (Recall from Table 15 that the fleet mix option in-
creased the aircraft NOX emissions by over 201.) The terminal area and the
runway ends experience higher NOX concentrations under this strategy as com-
pared to baseline conditions.
Aircraft are responsible for almost 80% of the airport NOX emissions
(see Table 14). Controls placed on other emission sources are not likely to
have a large impact on the NOX problem.
The same cautions about using a nonreactive dispersion model for a
reactive pollutant as were discussed in the HC analysis apply here.
5.2.2 Worst Case Conditions
In addition to the consideration of normal seasonal meteorology, it
is important to study the effect of a "worst case" situation on airport air
quality. The meteorological conditions used for this analysis were modifica-
tions of the fall conditions shown on Table 19. The wind direction was main-
tained at 17° since this resulted in the advection of the emissions from the
City of Atlanta over the airport. The wind speed was reduced to 2.0 m/sec,
the atmospheric stability was increased to class 5, and the mixing height was
lowered to 100 m. In addition, it was assumed that aircraft ground movements
were severely impaired and long takeoff queues were formed. Queue lengths four
times normal were used; this represents about 16 aircraft in the queue for
runway 8/26 during the hour from 11 M to noon.
This combination of high aircraft emission rates and poor atmospheric
ventilation results in the buildup of pollutant concentrations on the airport
and in the immediate environs. All of the control strategies were applied to
this condition in the same manner as for the normal seasonal conditions with
one exception. The engine shutdown strategy was assumed to be in effect, on
outbound as well as inbound aircraft. The queue lengths were long enough to
-------
84
extend onto controlled portions of the outbound taxiways and hence satisfied
the conditions for imposition of the strategy on departing aircraft.
Figures 12-14 show the pollutant concentrations for baseline condi-
tions and Table 23 indicates the effect of the strategies on the concentrations
at the various locations. It is evident that the worst case situation results
in substantial increases in pollutant concentrations at all locations. The
Delta Jet Base, the Eastern hangar and the central fire station are sustaining
increases in excess of 300% over normal conditions. In addition, the isopleths
show substantial increases in CO and HC concentrations south of the western ends
of the runways. These are due to the effects of the queues.
None of the CO readings are violating either the one-hour or eight-
hour National Ambient Air Quality Standard. The hydrocarbon values are far
above the standard with the worst receptor being an order of magnitude over.
In general, the control strategies have a somewhat smaller relative impact on
air quality under worst case conditions than under normal conditions. This is
primarily a result of the increased ijnportance of the environ emissions on air
quality. It is evident from the isopleths that regions upwind of any aircraft
activity are experiencing similar elevations in pollutant concentrations re-
sulting from environ sources.
As with the normal conditions, none of the strategies is effective
in insuring attainment of the ambient air quality levels specified by the na-
tional standards. With this worst case condition approaching the proportions
of an air pollution episode, it would be necessary to implement some form of
drastic emission reduction measures on all sources in the region to protect the
public health. Clearly, the airport is not solely responsible for the high
readings but is definitely a part of the problem. Application of episode
control measures on airport operations, such as a suspension of activity, would
have a definite impact on air quality on the airport site but might not pro-
vide for total relief unless the regional source emissions were also sharply
curtailed.
-------
85
CJ3
<:
OL
o
3:
i
o
o
o
to
-------
86
UJ
CD
oc
13
O
CD
n.
oo
z.
o
O
O
o
H
-P
H
CO
0
t/>
ni
U
1
H
-P
C
CD
o
-------
87
-------
88
rt
£
H
s
a
1
0)
So
i
§~o
r, nj
>H TO
(/I "O
t/l C
a in
tfP
Cu C 0
5O r
O^-'
0
OO
a
00
^
g
H
00
"*!
O 5
.5-8
&04-J
[3 r§
rH
O E C
C O -S
5 .H
W C
o o
c
rH
(2
g
H
4-J
rt
3
OOO
OOO
1 '
m cn r^
00 O OO
cn \o ^t
to
rH tO O
000
+ + +
o cn cn
-O OO CTl
OO O 00
to
OOO
000
LO oo r-
rH \o cn
oo o oo
to
rH rH O
000
o \o c--
CTi \o cn
t^ o oo
cn ^o *3"
to
000
OOO
O.rH LO
rsi t^ cn
oo o oo
to
o r- to
rH rH rH
O rH r-
ooo oo
ro
5
00
C
>H
r.
(2
.. g^ g
i i
.5
(U
rnrsj ro
Cn rsi rsi
* rsj i
0-0
tO rH O
rg rH m
LO r-t
OO O r-j
r j rH rsi
tO TJ- rH
00 -*
S!5§
to
1-ri ,0
\o oo to
o m rsi
r-j LO oo
ro to in
in rH
r-tM *>
to to r^
ro tO rH
m «* o
o r>- r--
oo cn -*
r-- cn rH
O rH O
o o m
rH m GO
rsi o r--
in rH
rH o cn
ro o o
rH rH rH
o in oo
cn rsi oo
LO ro r-*
in rH
^
a
%
3
S^ §
r-4
a
.5
5
CT» o rj
O *O O
,
CO O r>-
oo oo cn
O r*j rsi
Csl
rH^J in
0-rf O
+ ' +
to r j r>-
Ss?i
rvj
rHT- 0
OOO
rO OO rH
r>- in \o
O O Ol
rH tO r J
rsi
rsio O
OrH O
4- 4- 4
ro r i to
"* rH O
rH rH Cn
rst
KlrH O
or-j o
to in r-i
tO rH O
o o cn
rsi
ro O O
rsi Psj ro
ooo rsi
cn oo \o
oo cn
rH tO fsi
rsi
a>
<$
CQ X
0) ""
03
4-*
rH
rH rsi rH
OOO
o o in
rsiO rH
O ro in
rsi
o rsi to
«H ro o
444
o m cn
OO rH rj
rsi <«^ in
Tf tO tO
r-j
rH T rH
OOO
o TT r-.
c-i Q> ^H
o rsi in
^t ro ro
rj
r- oo rj-
oo o
O ro r-.
cn oo o
roro to
r-i
OOO
OOO
o oo o
m o csi
o to in
r-i
r- tO rH
ro oo rsi
ro rH ro
OOO O
in o rsi
o ro m
^t to to
rsi
f-i
1
l8Si
E
(U
2
rO rH O
OOO
,
o en r-
ro oo \o
O ro rsi
r>- ro *t
r-i
rH rH O
OOO
1 *
m o cn
o en \o
rH tO rj
rg
O rH O
000
in rH cn
rH cn o
rH tO rvl
r-- ro Tt
r-i
tO -«t O
OOO
1 1
in Oi CTt
to r- o
oro rg
r-.ro-*
ri
coo
OOO
o ro cn
rg cn sD
rH to rg
Csl
oo ** m
OO Csi rg
r j rg rg
o to cn
rH tO rs|
r- ro TT
^
00
6
4-*
cd
H X
^s^i
05
(U
OOO
OO O
O ^t O
LOCn rH
oo o t^
roro to
rg
OOO
oo o
0** 0
LO CT» rH
oo o r--
rsi
OOO
000
0^ 0
m cn rH
co o r^
rO to tO
r-j
OOO
OOO
C -rf O
LO Cn rH
oo o r-.
to to ro
rg
0 C O
000
o-r o
m cn rH
oo O r-
eg
rH cn to
rg eg eg
o ^- o
men rH
oo o r-
roro ro
rsi
x
v 8^ 3
3
oro h-
ro oo rsi
, , ,
in oo oo
rsi o *-H
rO rg rg
rHrt ro
rg
* O rH
rHO rH
i t 4
o to *$
cn r- **
\O rO tO
rg
or^i in
O-H 0
m m o
\o cn cn
oo m rj
rH -* ro
Csl
rg o Cn
to oo o
o cn r-
o r- r>-
ro rsi fNi
rH ^- tO
Cs|
r- rH 0
O rg o
' ' 4
m in cn
^- m o
oo m to
rg"3"
rg ^- cn
oo oo cn
to rH ro
m rg oo
cn m o
cn \o ro
rH ^a- ro
rg
g
H
4-1
ra
-------
89
6.0 STRATEGY IMPACT ON REGIONAL AIR QUALITY
This section will deal with the airport's impact on regional air
quality and the effectiveness of each of the control strategies in reducing
adverse effects.
6.1 EMISSIONS
As was previously discussed, the emission inventory for the Atlanta
area was assembled from the point source file of the Georgia Department of
Natural Resources and from an area source inventory generated from census data
and traffic information from the Georgia Highway Department. The point source
file covered the 10-county area surrounding the airport. The area source emis-
sions were displayed on a grid extending to 20 km from the airport boundaries.
The grid square sizes were chosen to match the resolution of the available
data. Figure 15 shows the grid arrangement. The interstate highways surrounding
the airport were modeled as line sources rather than area sources to improve
the spatial resolution of the emission pattern.
Table 24 shows the breakdown of environ emissions by source. Table
25 gives the contribution of the airport emissions to the regional total under
baseline and alternative strategy conditions. It is evident that the airport
makes a contribution in the vicinity of 3-4% to the regional CO, HC, and NOX
emissions. Regionwide, CO emissions come predominantly from transportation
sources (i.e., motor vehicles). The airport's contribution amounts to about
half of the total of the point sources. Hydrocarbon emissions originate mostly
from motor vehicles and evaporative sources (e.g., gasoline marketing, dry-
cleaning, solvent use). The airport contributes twice as much HC as the point
sources. This may be a result of the lack of any significant HC-producing
industries in the region (e.g., chemical processing facilities). For NOx,
the point sources and motor vehicles dominate and the airport is roughly
equivalent to the space heating sources. In light of this emission compari-
son, the airport represents a significant concentration of sources. The engine
emission standards have the greatest effect on regional emission loads, as
shown on Table 25.
-------
90
ACWORTH
0123 5
KENNESAW
SCALE - MILES
COUNTY LINES
CITY LINES
INTERSTATE HIGHWAYS
RIVERS
COB8 CO
COWETi
Fig. 15. Grid System for Inventorying Environ Area Sources
-------
91
TABLE 24. Atlanta Region Emission Inventory
Source
o
Point Sources
Area Sources
Transportation0
Space Heating
Refuse Disposal
Evaporation
Line Sources^
Airport
Regional Total
(10 3
CO
11.2
233.5
.4
12.1
6.8
8.6
272.6
Emissions
metric tons/yr)
HC
1.6
28.4
0.1
4.6
41.4
0.9
3.5
80.5
NOx
26.4
32.9
2.5
1.7
2.2
2.6
68.3
For 10-county region
Extending to 20 km from the airport boundary
CExcluding the airport
Residential, commercial/institutional, and industrial
eOpen burning and on-site incineration
Drycleaning and solvent use
^Roadways surrounding the airport
Baseline conditions
TABLE 25. Contribution of Airport Emissions to the Regional Total
Strategy
Baseline
Engine shutdown
Towing
Capacity Control (701 LF)
Fleet mix
Engine emission standards
Airport '
CO
3.2
3.1
2.3
2.9
2.4
2.0
\ of Regional
HC
4.3
4.3
2.9
4.0
2.7
2.2
Emissions
N0x
3.9
3.9
3.9
3.5
4.7
2.3
-------
92
6.2 AIR QUALITY IMPACTS
6.2.1 Normal Conditions
Of special interest to the analysis of the airport's regional impact
is the extent of influence of the airport sources alone on air quality. Fig-
ures 16-18 attempt to answer this by displaying isopleths that have been cal-
culated using only the airport emission sources. All other sources have been
zeroed. The fall and summer meteorological parameters are the same as the
normal conditions used in Section 5.0.
The first point of interest in the figures is the limited lateral
extent of the airport's influence. Concentrations drop off rapidly with dis-
tance perpendicular to the wind line. The lack of substantial crosswind
spreading implies that the airport has very little influence on areas that
are not directly downwind of it. The fact that the high concentration areas
are larger for fall conditions than for summer conditions is due to the lower
mixing height in fall (see Table 19).
For CO, the airport does not appear to be creating any regional
problems in attainment of the National Ambient Air Quality Standard. This
is consistent with the previous evaluation of airport air quality, which also
showed no CO problem. For hydrocarbons, the airport sources alone are close
to causing a violation of the 160 yg/m3 standard under summer conditions and
do result in an excess under fall conditions. It should be reemphasized that
the standard is written for a three-hour averaging time from 6-9 AM and
these calculations are for one-hour between 11 AM and 12 noon. Neverthe-
less, there are indications that the combination of airport and environ
emissions might result in a violation of the hydrocarbon standard. The three-
hour average calculations (which will be discussed later) do, in fact, confirm
this. For NOX, the airport is contributing a little less than half of the
100 yg/m3 annual standard under both summer and fall conditions.
Regional pollutant levels from all sources in the emission inventory
are displayed on Figs. 19-21. Under summer conditions with the wind from the
southwest quadrant, the airport lies downwind of a relatively undeveloped area
with little emission activity. Consequently, pollutant concentrations are
low upwind of the airport and increase sharply at the airport site and beyond.
The high concentrations calculated in the vicinity of Hapeville are, to some
-------
93
Lul
et
CC.
ZD
O
O
H
4-)
H
1
.S
iI
d>
II
I
B
I
10
(D
U
£
5!
O
O
8
+J
O
O
H
bO
H
P-,
-------
94
=c
OL
ZD
O
I
CJ3
oo
o
LLJ
O
O
O
8
O
u
a
H
PQ
JH
0
13
-------
95
trs
QL
^3
O
I
P
I
s
1I
(D
a
PQ
§
U
rt
g
oo
txo
H
-------
96
CD
<:
OL
UJ
>
<
D£
ID
O
3C
t
in
g
H
0
0)
O
H
P
CO
z
O
O
O
I
CP>
b
H
PL,
-------
97
a:
LU
-------
98
LU
CU
QL
Z3
O
00
z
O
O
O
O
J--
g
H
M
H
-a
m
-8
1
H
fi
I
g
H
bo
CM
bO
H
-------
99
degree, a result of the intersection of Interstate Highways 75 and 85, which ar<
modeled as line sources. The southwest wind moves almost parallel to 1-85 and
concentrates the emissions from the entire length of the line segment, thereby
creating the hot spots shown on the map.
'* Under fall conditions the airport is downwind of the Atlanta central
business district (CBD) and several other neighboring urban areas. Conse-
quently, there is a significant quantity of emissions being transported across
the airport and into the surrounding areas to the south.
It is evident that under both summer and fall conditions the high
concentration zones in the vicinity of the airport are of the same order of
magnitude as those in the vicinity of the Atlanta CBD, although generally not
as extensive in area. It can therefore be stated that the airport is roughly
equivalent to the CBD in terms of its emission density and corresponding im-
pact on regional air quality.
Another means of describing the airport's contribution to regional
air quality is to determine the effect of airport sources on pollutant concen-
trations along a line parallel to the wind direction and extending both up-
and downwind of the airport. As previously indicated on Figs. 16-18, this
will represent the maximum impact since the lateral spread of pollutants per-
pendicular to the wind is extremely limited for the airport sources. Figures
22 and 23 show plots of calculated concentrations along the wind line that
runs through the airport location point (ALP). (The ALP is a geometric code
point used to identify general airport locations in a national perspective.
The Atlanta airport ALP is located at the intersection of taxiways C and D in
approximately the center of the field as shown on Fig. 2.) No attempt was
made to include the airport concentrations on the figures, as the detailed
modeling carried out makes the calculated concentration very sensitive to re-
ceptor location and the results might present a distorted picture of the
actual situation.
Concentration profiles in Fig. 22 emphasize the low level of pollu-
tants southwest of the airport that was discussed previously. Total concen-
trations begin to rise about 2 km upwind of the ALP, where modeled freeway
segments produce a rise in concentrations from environ sources and inbound
taxiing by aircraft landing on runway 27L causes the first appearance of air-
port pollutants. Receptors upwind of the ALP are spaced at 2 km, hence fail
-------
100
CO
LLJ
O
X
o
o
cc
g 100
Li-
O
o
I
cc
(
z
LU n
z
o
~r
_L
-14 -12
228°(SW)
-10 -8 -6 -4 -2
UPWIND
6 8 10 12 14
DOWNWIND 48°(NE)
DISTANCE FROM AIRPORT LOCATION POINT (ALP), km
Fig. 22. Wind Line Pollutant Profiles Under Baseline Conditions, Summer
-------
101
noo
1000-
900~
800-
S 700
600
500
o
^
o
400
300
200
100
400
° 300
200
100
300
-ALL SOURCES
AIRPORT
-ENVIRONS
ALL SOURCES,
-14 -12 -10 -8 -6 -4 -2 0 2 4 6 8 10
I7°(NNE) UPWIND DOWNWIND
DISTANCE FROM AIRPORT LOCATION POINT (ALP), km
12 14
I97°(SSW)
Fig. 23. Wind Line Pollutant Profiles Under Baseline Conditions, Fall
-------
102
to pick up fine structure of the profiles near concentrated sources such as
roadway and taxiway lines. Downwind receptors are 1.5 km, 2 km, 3 km, and
4 km from the ALP and then are spaced at every 2 km beyond. The peaks in
concentrations from airport sources 2 km from the ALP come where the wind
vector crosses the remote parking lots northeast of the terminal. The environ
peaks at 4 km are due to the 1-75 expressway segments east of Hapeville. The
broad peaks in environ concentrations at about 12 km from the ALP correspond
to the general buildup in source densities for areas nearer the center of
Atlanta. Itecatur is slightly beyond the ends of the curves displayed at
approximately 16 km from the ALP.
The airport produces less than half of the calculated total carbon
monoxide concentrations at receptors farther than 3-1/2 km from the ALP; it
produces less than half of the nitrogen oxides beyond 8 km; but it causes
more than half of the calculated hydrocarbon concentration even at 14 km from
the airport. At 14 km, airport sources cause 30% of the calculated carbon
monoxide concentration, 32% of the nitrogen oxide concentration, and 62% of
the hydrocarbon concentration.
With the wind from the north-northeast, as in Fig. 23,, central
Atlanta sources produce broad peaks in the pollutant concentration profiles
upwind of the airport. A steep, almost linear rise in all profiles beginning
at -6 km is a happenstance due to almost ex ict coincidence of the line of
receptors with modeled segments of 1-85; the concentrations rise quickly as
more of the roadway length is located upwind of receptor sites. Concentra-
tions from line sources decay sharply with distance from the line, as shown by
return of environ concentrations to more modest values downwind of the airport.
The environ peaks between 4 and 5 km downwind of the airport are from 1-285,
crossed here perpendicularly, in contrast to the tangential encounter with
1-85. Relatively large pollutant levels from environ sources in Atlanta are
sustained downwind of the airport, where few additional sources are available
to augment the levels. Airport sources cause high pollutant levels near the
airport that decrease smoothly with distance.
Airport contributions to carbon monoxide and nitrogen oxide total
concentrations drop off to less than half the total within a short distance.
Once again, however, the airport produces more than half the calculated cot'i
hydrocarbon concentration, even at 14 km from the airport. At 14 km, airpo."
contributions to carbon monoxide, hydrocarbon, and nitrogen oxide concentrr ions
are 25%, 52%, and 28%, respectively.
-------
103
The same general considerations regarding the jjnpact of airport sources
on the attainment of the National Ambient Air Quality Standards that were dis-
cussed under the airport impact analysis carry over to the regional considera-
tions. That is, there does not appear to be any problem with CO; the hydrocarbon
concentrations show a definite potential for standard violation; and the one-
hour NOX concentrations are near the annual average standard, but no definite
statement can be made without the long-term modeling results.
It must be reemphasized that these evaluations apply to the line of
maximum airport impact. Small displacements perpendicular to the wind line
result in substantial reductions in pollutant concentrations resulting from
airport sources.
The impact of each of the control strategies on regional air quality
is shown on Figs. 24-26. As would be expected, each strategy shows maximum
impact close to the airport and the distinctions between each strategy diminish
with distance. Nevertheless there is a discernible difference in impact among
the control options as far away as 14 km from the ALP.
An interesting observation can be made about the comparison between
the strategy impact on the wind line profile and on the airport emissions
(Table 15). For CO and HC the strategies "line up" in the same relative order
of effectiveness on the wind line profile as they do on emissions. The excep-
tion is the towing strategy, which affords the greatest impact on wind line
concentrations but is second in terms of emission reduction behind the emission
standards. At 6 km from the ALP under fall conditions, the towing strategy
results in a 23% reduction in CO concentration as compared to 151 for the
engine emission standards. This is the same effect as was described in the
airport evaluation; that is, the towing strategy changes the spatial emission
pattern enough to realize a greater air quality improvement than would be
expected from the emission change alone. The evaluation of the wind line
-iofiles shows this effect is felt even far downwind of the airport.
For NOX, the increase in emissions resulting from the fleet mix option
is evident downwind as far as 14 km. As before, the engine emission standards
ffer the greatest reductions in NOX concentrations.
-------
104
500
CO, SUMMER
400
300
200
100
1 T
BASELINE
ENGINE SHUTDOWN
CAPACITY CONTROL
FLEET MIX
TOWING
ENGINE STANDARDS
~T T
i i i
-14 -12 -10 -8-6-4-2 0 2 4 6
DISTANCE, kilometers
10 12 14 " 16
,250, , , r
CO, FALL
1000
750
cc
h-
z
500
250
BASELINE
ENGINE SHUTDOWN
CAPACITY CONTROL
FLEET MIX
TOWING
ENGINE STANDARDS
-14 -12 -10 -8-6-4-2 0 2 4 6
DISTANCE, kilometers
10 12 14 16
Fig. 24. Strategy Impact on Wind Line CO Profiles
-------
500
HC, SUMMER
400
300
200
100
BASELINE
ENGINE SHUTDOWN
CAPACITY CONTROL
FLEET MIX
TOWING
ENGINE STANDARDS
-14 -12 -10 -8 -6 -4
-20246
DISTANCE, kilometers
10 12 14 16
500
h HC, FALL
400
E
"5. 3001
=*- L
200 h
1001
BASELINE
ENGINE SHUTDOWN
CAPACITY CONTROL
FLEET MIX
TOWING
ENGINE STANDARDS
J L
-14 -12
-8 -6-4-2 0 2 4
DISTANCE, kilometers
10 12 14 16
Fig. 25. Strategy Impact on Wind Line HC Profiles
-------
L06
125
1 1 1 1 I
NOX, SUMMER
100
O
O
75
50
I-
L
25
BASELINE
ENGINE SHUTDOWN
CAPACITY CONTROL
FLEET MIX
TOWING
ENGINE STANDARDS
_L
-14 -12 -10 -8
-6-4-2 0 2 4
DISTANCE, kilometers
10
500
400
300
200
100
1 1 1 T
NOX, FALL
BASELINE
- ENGINE SHUTDOWN
CAPACITY CONTROL
FLEET MIX
TOWING
ENGINE STANDARDS
_L
_L
-14 -12 -10 -8 -6-4-2 0 2 4
DISTANCE, kilometers
14
16
Fig. 26. Strategy Impact on Wind Line NO Profiles
-------
6.2.2 Worst Case Conditions
The same worst case conditions of poor atmospheric ventilation and
high aircraft activity that were evaluated for their ijnpact on airport air
quality were also evaluated for their impact on regional air quality. Figures
27-29 show the regional isopleths under these conditions. Comparison of these
figures to the fall conditions on Figs. 19-21 indicates the impact of these
adverse conditions. Two things are immediately evident. First, the geometry
of the isopleths assumes a more definitive "plume" shape following the general
wind direction. The lobes and distortions in the isopleth lines under normal
conditions disappear as the low lid height and light winds promote a uniform
mixing of pollutants under the lid and inhibit any lateral dissipation of the
concentration. This is the same type of behavior as can be observed for a
single point source emitting under the same conditions.
The second observation is that the high pollutant concentration lines
begin upwind of the airport. The City of Atlanta plays a significant role in
the generation of the calculated concentrations and the airport, with its
increased emission rate, compounds the situation.
As in the airport impact analysis, nowhere in the region is the
National Ambient Air Quality Standard for CO being violated, even under these
worst case conditions. There are numerous locations up- and downwind of the
airport where the hydrocarbon limit is being exceeded. The 200 yg/m3 isopleth
appears to originate just downwind of the Atlanta CBD and extends far south of
the airport. The airport makes a significant HC impact in the areas just
downwind with the effect dropping off rapidly in the lateral direction. For
NOX, the high concentration zone as measured by the 300- and 150-yg/m3 isopleths
also begins just south of the Atlanta CBD and extends far to the south.
Table 26 shows the effect of each strategy on the concentrations
downwind of the ALP. The worst case conditions have their largest relative
impact on the region far downwind; the increase is almost a factor of 10.
This area has very low concentrations under normal conditions due to its re-
latively undeveloped condition. The strategies have diminishing impacts in
these areas. As before, the towing control option provides maximum air quality
improvement for CO and HC and the engine emission standards for NOX. The fleet
mix change results in an increase in NOX concentrations and the engine shut-
down and capacity control strategies provide only small changes.
-------
108
ALL CONCENTRATIONS IN yG/M3, 1-HOUR AVERAGE
WIND
DIRECTION
HARTSFIE
ATLAN
INTERNAT
AIRPO
Fig. 27. Regional CO Concentrations for Worst Case Situation
-------
ALL CONCENTRATIONS IN yG/M3, 1-HOUR AVERAGE
WIND
DIRECTION
Fig. 28. Regional HC Concentrations for Worst Case Situation
-------
110
ALL CONCENTRATIONS IN MG/M3, 1-HOUR AVERAGE
WIND
DIRECTION
HARTSFIE
ATLAN
INTERNA
AIRPO
Fig. 29. Regional NO Concentrations for Worst Case Situation
A.
-------
03
in
0
t P- 4
-p
H
P!
o
C_J
0>
10
Oj
-p
in
fH
O
10
Pi
0
-p
cti
P
a
CD
£
0
CJ
g
X
r\
8
i
rt
O
H
bo
(S
.
CXI
H
m
E-!
0
°X° ^
6
C T3
O r*
!/} "T3
B *J
UJ CO
00
°ra S
.C
u
tlJ X
r-1 *.
H
CD C
00 O
u"i
P
0)
-H
i-H
O
ra
cu
o
S
I/) CM
H ,_J
' p
H 5-.
£ V.
i
r^- oo cxi
LO CO OO
71 *?
Ol LO ^t
LO CO MD
O rH O
1 '
O LO CTi
P^ ^ "^
>o
^ oo to
LO ex) Ch
to r- «*
tO CO --H
LO tO CTi
(Nl r^ '
o r- TT
\O ^J~ *3"
CX)
(X] r-j o
(xj *^- O
i~- OO ^O
O O CO
^t OO "^f-
to
oo ^H r-j
O * i-H
uo to \o
CO ^t CO
^ CO "3-
to
X
r-i
IO CO tO LO ^3"
*3" Tj" CTl <~i OO
r-t to i ( 1 rxi
^J- rsi r-t i-H tO
en r~^ ^}~ (x) oo
r^ Tt -* LO to
OO CO LO rH i 1
en r^- (xi r- cxi
l CXI + "CXI
1 '
r-H K) OO LO r-
S ^ ** (S «*
LO ^f *^" tO tO
CX) CXl
I 1 CTi Ci LO O
(X| to O rH tO
,
CM \o LO en
i 1 O *^t t^-- LO
tO cxi
t~-~ o (xj en en
o to o *wD I-H
rH ^ \D ^ LO
>O C^l CO i-H tO
cxi r-- TJ- co LO
to cxi
X
8 y S 8 ^
-^> -r3-
cn
oo
CO
ro
to
*-}-
^D
LO
^"
^
7
LO
CXI
o
LO
LO
t-H
O
O
r-
to
rH
LO
cn
r-
ro
X
t>Q
2
§
^
^
m"
DJ3
.5
g
H
a)
^
C
O
c
o
o
rH
rH
n)
-------
112
6.2.3 Hydrocarbon Analysis
As indicated in previous discussions, comparison of the calculated
hydrocarbon concentrations to the National Ambient Air Quality Standard re-
quires a computation of a three-hour average for the hours of 6-9 AM. Since
the AVAP Short-Term Model makes its computations on a one-hour time scale, the
three-hour average is calculated from the results of each individual hour. The
model does not store information from the previous hour's calculations and so
does not account for any changes in concentration that might result from a
change in emission characteristics or meteorology that occurred longer than an
hour away in time. The lack of an algorithm to represent photochemical reac-
tions involving hydrocarbons has already been discussed. The results of this
analysis, therefore, must be viewed in the light of the model's limitations.
In making AVAP model runs for the hours 6-7, 7-8, and 8-9 AM, the
diurnal distribution of emission activity is included for each hour, Since the
air quality standard allows only one excess per year, the meteorological condi-
tions chosen for this analysis were the same as the worst case conditions pre-
viously described. It is not unreasonable to assume that the light winds and
low lid would persist for three consecutive hours. Also, the aircraft activity
in these hours is fairly high (see Table 5) indicating that long queue forma-
tion is possible under adverse visibility conditions.
Figure 30 shows the three-hour average concentrations calculated for
baseline conditions and the towing and engine emission standards control strate-
gies. It is evident that upwind of the airport the standard is being violated.
The airport adds substantial HC emissions and boosts the concentration even
higher downwind. Note that the calculated concentrations resulting from air-
port sources only is still above the 160 yg/m3 standard. The indication is
that emissions from the airport alone could result in violation of the standard.
The two control strategies tested provide significant improvement
although neither is capable of reducing the concentrations below the standard.
Given the high HC levels being transported over the airport from other sources,
this condition is not unexpected. The fleet mix strategy was riot tested here
because it resulted in increased NOX concentrations.
-------
113
1 I I
I I I
I I T
C/5
O
CC
O
«i
5
Crt
-------
114
6.2.4 Long-Term Air Quality
The long-term version of the AVAP model was used to compute annual
average pollutant concentrations for the airport and vicinity. Because this
computer package requires very long running times (in the vicinity of one hour),
the receptor grid used for the calculation was made coarser and the number of
receptors was reduced in order to achieve machine time savings. The fine grid
on the airport site was removed and calculations were made only for the eight
GEOMET monitor site locations and the Airport Location Point (see Fig. 3).
The regional grid was enlarged to 4 x 4 km (as compared to 3 x 3 km previously)
while covering basically the same area.
Figures 31-33 show the isopleths of calculated annual a.verage concen-
trations. Tables 27-29 show the computed concentrations at nine regional re-
ceptors, the center one of which is in the approximate center of the airport
(see Fig. 15 for location of receptors) and the extreme ones of which are on
lines 4 km away. Also shown are the concentrations calculated at the eight
GECMET sites, the ALP, and the worst non-airport receptor.
From the tables it is evident that airport sources contribute only
small amounts to the annual average concentrations at the receptors 4 km away;
there is a maximum of 37.1 yg/m3 of CO, 15.2 ;ig/rn3 of HC, and 7.6 yg/m3 of NOx
contributed by the airport at these sites. In contrast, the environs contrib-
ute substantial amounts to the concentrations on the airport sites; for CO it
is in the range of 230-380 yg/m3, for HC 68-96 yg/m3, and for NOX 42-83 yg/m3.
The environ contributions at receptor number 7 are significantly
higher than at other sites primarily due to the influence of the long stretch
of 1-85 nearby. The hydrocarbon concentrations due to airport sources at sites
1 and 2 are high since these two locations are close to fuel fanns and hence
are exposed to large quantities of evaporative emissions. Receptors 7 and 8
lie under the approach and departure paths for runway 8/26 and hence experi-
ence the highest NOX concentrations since aircraft NOX emissions are highest in
the approach and takeoff power settings. That similar high NOX levels are not
calculated at receptors 3 and 5, which are near the flight paths for the southe-n
runways, may be a result of the fact that one runway is used for departuree
and the other for takeoffs. The separation distance provides added disperse >n
space and so may result in the lower values.
-------
ALL CONCENTRATIONS IN yG/M3, ANNUAL AVERAGE
20V I ATLANTA
DECATUR
; EAST POINT .
rj' 400 r/"
HAPE-
VILLE
JFORiST PARK
HARTSFIELD
ATLANTA
NATIONAL
RIVERDALE
CLAYTON
FAYETTE CO,
JONESBORO
-I-
Fig. 31. Annual Average CO Concentrations Under
Baseline Conditions
-------
116
ALL CONCENTRATIONS IN yG/M3, ANNUAL AVERAGE
Fig. 32. Annual Average HC Concentrations Under
Baseline Conditions
-------
ALL CONCENTRATIONS IN yG/M3, ANNUAL AVERAGE
ft-t-
HARTSFIELD
ATLANTA
RNATIONAL
FAYETTE CO,
\
-I-
Fig. 33. Annual Average NO Concentrations Under
Baseline Conditions
-------
118
TABLE 27. Annual Average CO Concentrations for Baseline Conditions
All concentrations in yg/m3
UTM a
Y- Coordinate
(km)
UTM
734.5
13.0
3729.S/ 262.9
275.9
24.4
3725. 5/ 215.8
240.2
10.3
3721. 5/ 160.6
170.9
X- Coordinate3
(km)
738.5 742.5
28.3 18.1
332.5 313.9
360.8 332.0
372.2 37.1
255.5 265.4
627.7 302.5
12.1 20.7
194.0 223.8
206.1 244.5
Airport
Environs
Total
Contribution to Concentration
(yg/m3)
Receptor
GEOMET #1
#2
#3
#4
#5
#6
#7
#8
Airport Location
Worst Non -Airport
(738.5, 3737
Airport
429.0
252.2
91.6
55.9
69.5
158.5
189.0
249.7
Point 287.9
Receptor 4 . 7
.5)
Environs
256.1
245.6
255.5
232.3
247.1
247.5
381.1
281.9
272.1
619.0
Total
685.1
497.8
347.1
288.2
316.6
406.0
570.1
!,31.6
560.0
623.7
universal Transverse Mercator coordinate system, zone 16.
-------
TABLE 28. Annual Average HC Concentrations for Baseline Conditions
All Concentrations in
UTM
734.5
5.6
3729. 5/ 81.9
87.5
UTM 10.6
Y-Coordinatea 3725. 5/ 67.1
(tan) 77^7
4.5
3721.5 50.1
54.6
yg/m3
X-Coordinatea
(km)
738.
12.
101.
113.
140,
80.
220.
5.
57.
62.
5 742.5
1 7.8
1 96.4
2 104.2
4 15.2
1 82.3
5 97.5
3 8.9
0 65.1
3 74.0
Airport
Environs
Total
Contribution to Concentrations
(yg/m3)
Receptor Airport
GEOMET #1 193.9
#2 115.5
#3 38.2
#4 22.8
#5 27.7
#6 77.4
#7 79.2
rf8 95.7
Airport Location Point 145.4
Worst Non-Airport Receptor 3.4
(746.5, 3717.5)
Environs
80.8
74.0
73.6
68.1
71.5
76.7
96.2
87.0
85.4
144.1
Total
274.7
189.5
111.8
90.9
99.2
154.1
175.4
182.7
230.8
147.5
Universal Transverse Mercator coordinate system, zone 16.
-------
L20
TABLE 29. Annual Average NOX Concentrations for Baseline Conditions
All Concentrations in yg/m3
UTM
Y-Coordinatea
(km)
UTM
734.5
2.1
3729. 5/ 40.7
42.8
4.4
3725.S/ 35.2
39.6
2.1
3721.5/ 27.3
29.4
o
X- Coordinate
(km)
738.5 742.5
3.3 2.7
53.8 52.8
57.1 55.5
42.2 7.6
45.2 46.8
87.4 54.4
2.2 4.1
33.6 36.5
35.8 40.6
Airport
Environs
Total
Contribution to Concentrations
(Ug/m3)
Receptor
GEOMET #1
n
#3
#4
#5
#6
#7
#8
Airport Location
Worst Non-Airport
(738.5, 3737
Airport
44.2
24.7
26.6
15.0
32.4
20.9
46.2
115.6
Point 43.4
Receptor 0 . 8
.5)
Environs
45.4
43.0
47.9
42.0
47.1
43.8
83.1
51.2
48.0
90.8
Total
89.6
67.7
74.5
57.0
79.5
64.7
129.3
166 . 8
91.4
91.6
.*-
Universal Transverse Mercator coordinate system, zone 16.
-------
The combination of airport- and environ-contributed concentrations
results in a violation of the National Ambient Air Quality Standard for N02
(100 yg/m3 annual average) at two airport locations (7 and 8) and the calcu-
lated air quality being within 20% of the standard at three other locations
(1, 5, and the ALP). The region in excess of the standard is confined prin-
cipally to the airport at the ends of the runway. It must be emphasized that
the problem is a combination of airport and environ sources. At receptors 7
and 8 the airport is contributing about one-third of the calculated NOX con-
centrations .
It is interesting to note that for hydrocarbons, six of the receptors
are showing annual average concentrations that are above or very close to
the three-hour standard of 160 yg/m3. While this does not mean that the stan-
dard will be violated during the 6-9 AM time period, it does indicate that
hydrocarbons will be a perennial problem at the airport. As with the other
analyses, CO concentrations are very low.
The engine emission standards strategy was also run with the long-
term model as this was the only control option that addressed the NOX problem.
Figure 34 shows the annual average NOX concentration isopleths and Table 30
shows the impact of the strategy at the receptor locations. It is evident
that there is only a small impact on the receptors 4 km away from the airport
(maximum of 3.81 for CO, 7.31 for HC, and 5.0% for NOX) but significant impacts
on the airport site. The strategy shrinks the area in excess of the 100 yg/m3
N02 standard and also provides significant reductions at the sites that were
close to violation (1, 5, and the ALP). For hydrocarbons it reduces all points
below the 160 yg/m3 level. This strategy is, therefore, effective for long-
term NOX and HC control.
-------
122
ALL CONCENTRATIONS IN MG/M3, ANNUAL AVERAGE
20X I ATLANTA
HARTSFIELD
ATLANTA
RNATIONAL
FAYETTE CO,
\
4-
\-\i
Fig. 34. Annual Average N3X Concentrations for
Engine Emission Standards Strategy
-------
12,
crt
r-l
oj
13
o3
P
CO
e
o
H
to
°2
fl
m
s
H
ts
O
(J_i
m
w
o
to
a
po
* r-~
rH CM CM
LO LO LO
rH LO Ol
CM CM CM
to to to
LO
^*
to
O vO OO
CM OO rH
1 rH 1
1
rH rH rH
LO rH vO
to r~~ LO
00 T^- rH
LO r-~ r~-
to oo LO
O rH «*
=J- LO ^H;
i to i
i
OO CM CM
cn to oo
LO ^J- O
rH rH
tO LO CM
CM O tO
vO CM rH
CM rH
00 rH rH
rH t^- CM
1 (XI 1
^f tO rH
CM 1^- tO
O LO LO
CM TH^ to
rH t-~ OO
vO l^ O
O CM vO
CM vO to
LO LO LO
t i LO cn
CM CM CM
to to to
LO
OO
to
t^- o
to LO
1 1
rHt-
Ol rH
tO LO
vO-t
O«3-
^1- LO
oo to
LO r-~
i i
r---^
cn o
vocn
O LO
"* r-~
t>_ cn
cn oo
CM tO
i i
*± cn
r--o
to cn
CM CM
UO LO
^- CM
* o
CM tO
LO LO
rH LO
CM CM
to to
LO
CM
vO
rH
1
VO
,3-
LO
LO
LO
LO
r}-
to
l
t~-
O
O
1 1
CM
^j.
O
rH
r-^
rH
LO
vO
CM
to
0
CM
to
to
LO
cn
CXI
to
to vOOO
cn to to
rH rH rH
1 1 1
tO LOCM
CM OO ^t
t~-~ LO vO
vo r-- LO
cn t^ ^±
OO vO t~~
cn vo t--
to oo r-
* to i i
i i i
rH rj- O
«* vO CM
LO rH C7>
rH rH
r~- LOCO
<* cnr-H
r-- oo rH
CM rHrH
t-- OOO
rH LO O
tO CM rH
I I 1
O *3" *d"
oo cncxi
VO VO rH
* to to
rH OOrH
LO t^- t^
oo cn ^f
VO 'a-IO
rH CM tO
Htfc -It ntt
O
H
CO
flj
fc
C3
s
LO CM ^t
Cn OO rH
1 rH rH
1 1
vO O tO
rH LO 1^
LO vO LO
O LO t^-.
r~~ cn «*}
LO t-~ VO
r-- CM o
* VO VO
rH rH CM
1 1 1
LO rH rH
r~- to ^j-
I--- OO rH
rH
Cn CM rH
o cn **
cn cn LO
rH
tO rH t^
oo cn vo
1 1 rH
1
^f cn i i
* r-~ oo
vO 00 to
CM CM IO
CM vO O
OO VO VO
00 rH O
CM tO ^
*d" LO VO
at =tt= =»t=
LO tO
LO cn
rH CM
I I
cMcn
cn r^
OrH
rH rH
(000
cnvo
CM vD
i 1 rH
O'St
LO tO
CM tO
I I
vo r^
rHrH
tO CM
rH rH
^t-
LOCM
r^- oo
rH rH
CM vO
too
rHCM
I I
i ICM
LOCM
cncM
rHvO
OrH
r-. to
LOLO
r^oo
-tfc ntfc
^
00
rH
1
vO
^
t
^
rH
cn
3-
to
to
1
vO
to
LO
rH
00
0
to
CM
vO
rH
CM
r
cn
00
to
0
o
vO
LO
p[
o
H
rt
3s
H
.p o
o
^
vO
rH
CD
c
O
g
s
to
to
rt
H
O
o
o
rH
O
CO ±J
e nj
bO rH
^ $£
rt
H CD
to
(/) rH
C
H t/J
t-* PH
t, t.
M H
P E~*
SrH
03
ti to
0 rH
CJ CD
rH -H
oT jT
-------
124
7.0 THE IMPACT OF GROWTH
This section will deal with the evaluation of the impacts of growth
and development in the Atlanta area on airport and airport-influenced regional
air quality.
7.1 DEVELOPMENT SCENARIO
Change in the Atlanta region with time will alter the quantity and
distribution of pollutant emissions. Because maintenance of satisfactory
air quality, once achieved, is a requirement for air quality control programs,
it is desirable that proposed aircraft control strategies be evaluated against
projected, as well as current, regional conditions. The airport model is
ideally suited for calculating the net effects of the interplay of changes to
the various sources in the region and evaluating the probable effectiveness
of aircraft control strategies. Information about possible levels of growth
and development patterns in the region have been combined with projections
of passenger enplanements at the airport to adjust the source inventory to
values appropriate for 1980 and 1990. Adjustments only in the magnitudes of
the emissions were made, with no changes in the geometric definition of any
source.
Projections of regional growth are dependent on the assumptions
used and the purposes to be served in making the projections. Regional growth
estimates used in this study are based primarily on information from three
sources. The Atlanta Regional Commission (ARC) supplied information^
regarding the distribution and growth of population and economic activity
throughout the region. Growth of industrial point sources has been based
on the projection of economic activity in the Atlanta region prepared for
the USEPA by the Bureau of Economic Analysis (BEA), U.S. Department of
Commerce. Studies performed for the Atlanta Airport Authority furnished
information about the projected levels of air traffic at the airport.
Information received from ARC is strongly conditioned by the
assumptions behind it and its intended purpose. As part of the Commission's
program to develop a plan for the region, several alternative development
outcomes, based on differing transportation scenarios, have been calculated.
The same projected overall regional population growth is distributed across
the region in alternative patterns determined by transportation-related
-------
attributes, such as accessibility. These alternatives are being used, in
part, to stimulate general public awareness and discussion of the possibilities
for regional development and to hopefully lead to concurrence on a set of
policies to enhance the prospects of attaining the desired development outcomes.
The changes with time in the environ area sources in the airport model are
based on the results of ARC calculations for one of these development scenarios,
the "null" alternative that considered "the implications of a limited future
transportation system for the region" consisting of no new highways and only
the already adopted plans for the MARTA rail rapid transit system. Examina-
tion of these results shows a development pattern that continues an expansionary
trend to 1980, after which poor accessibility at the fringes of the developed
area forces a recentralization of further growth.
Of direct use in the adjustment of the source inventory are tabula-
tions of census tract populations, occupied residences, proportion of multi-
family residences, and land areas occupied for commercial and for industrial
uses in 1970, 1980, and 1990. The jurisdictional boundaries of the towns of
over 2500 population chosen as the basis of the current source inventory are,
unfortunately, often not coincident with census tract boundaries. Growth of
towns, therefore, has been calculated in the following way: The average
growth rates for the important tabulated values for a set of census tracts
roughly overlapping a town have been applied to the 1970 base values for
the town itself. The boundaries of the towns have been assumed not to change.
Several pollutant generating activities are calculated to vary at the same
rate as the population, among which are waste incineration, gasoline con-
sumption, solvent use, and dry cleaning. Space heating emissions from
residential, commercial, and industrial units are increased by the separate
growth rates tabulated for each. The total emissions for each town and the
residual county-wide emissions are then transformed onto the regional grid
,/stem lescribed in Section 6.1.
Automotive traffic emissions projections are based on population
Ganges. Traffic on local streets has been assumed to vary with the popula-
tion in the same area; this traffic appears as area sources in the regional
,rrid. The traffic on freeways, on the other hand, probably is more strongly
dependent on the growth of overall regional population. The total vehicle-
viles on the freeway line sources near the airport have been, correspondingly,
-------
126
increased in. proportion to total regional growth. Traffic emission rates
appropriate to the vehicle age distribution and engine emission control
standards of 1980 and 1990 have been used.
Point sources beyond the airport boundaries are derived from the
inventory assembled by the Georgia Department of Natural Resources in the
National Emissions Data System (NEDS) format. An element of the information
for each source is the Standard Industrial Classification (SIC) code number
for the primary economic activity of the facility. The BEA projection of
economic activity in the Atlanta area provides growth rates for a number of
industries in categories compatible with the SIC coding system. These pro-
jections of growth to 1980 and 1990 have been applied directly to the
corresponding industrial point sources in our inventory, and all growth
in emissions has been assumed to occur in place, without, the creation of any
new point sources. Several of the types of "point" sources that, might be
rather diffuse, such as quarrying operations or clustering of stacks asso-
ciated with large governmental installations, have been entered into our
inventory as area sources on the basic regional source grid. The growth
of these sources, nevertheless, follows the BEA projections for the appro-
priate SIC classes.
Projections of numbers of passengers that will be using the Atlanta
airport have been used to alter the magnitudes of sources directly related
to passenger levels, foremost among which are access traffic and. use of
parking facilities. No major construction has been assumed, so that space
heating emissions from airport buildings remain unchanged.
Although the amount of aircraft activity will necessarily increase
to service the increased passenger levels, recognition has been made of the
fact that the aircraft in commercial use in 1980 and 1990 will likely be
different from the current fleet. In particular, it is anticipated that the
fleet mix will change toward domination by medium range and jumbo jet aircraft,
with a phasing out by 1980 of most of the older long-range aircraft (e.g. DC-8,
CV-880, etc.). This change in fleet mix is incorporated into the 1980 and
1990 inventories of aircraft activity as the baseline condition. The 1990
baseline conditions also include aircraft emission rates that reflect tb.^ engine
standards that will be universal by that time.
-------
7.2 STRATEGY IMPACT ON REGIONAL EMISSIONS
Changes in pollutant emissions with time result from changing
numbers of sources and from changes in source emission rates due, for example,
to compliance with emission control standards. Changes in the emissions of
three pollutants in the Atlanta region through 1990 are displayed in Fig. 35.
Total emissions from the inventory used for dispersion model calculations are
divided into two major categories: emissions directly attributable to airport
activity and emissions from all other sources in the study area, called the
environs. In general, the airport becomes a larger factor in the regional
emissions with the passage of time.
Relative distribution of baseline emissions among source sub-
categories listed in Table 31 reveals the causes of the overall behavior
shown in Fig. 35. Specific inventory elements in each subcategory are
detailed in Table 32. Changes in the environ emissions are strongly con-
ditioned by the dramatic decline in automotive emissions accompanying the
evolution of the vehicle model year mix to uniform compliance with more
stringent emission standards. The effect is most pronounced for carbon
monoxide emissions which are overwhelmingly dominated by automotive emissions.
Evaporation of hydrocarbons, primarily associated with gasoline marketing
and inventoried as part of the stationary area sources, nearly counterbalances
the improvement in hydrocarbon emissions from motor vehicles. Relative
improvement in emissions of nitrogen oxides from motor vehicles is somewhat
less than for carbon monoxide and hydrocarbons and is exceeded by the increase
in uncontrolled nitrogen oxide emissions from the large point sources in the
region. The result is a gradual increase in environ nitrogen oxide emissions
throughout the time period. The total number of vehicle miles traveled
annually in the region is continuously increasing, but this factor has been
lore than offset by the improved vehicle emission rates. Toward the end of
che pe iod, however, the full impact of the control of emissions will have
been attained, after which vehicle miles traveled would again become the
lominant factor.
The effect of motor vehicle emission control standards appears
i.mong airport related sources only in the ground mobile source subcategory.
Because passenger emplanements are anticipated to grow at a faster rate than
overall regional population, the increase in access traffic at the airport
-------
128
X
O
cc
a.
o
O
CO
o
o
CM
O
o
o
00
o
to
eo
CM o 25
SNOISSIA3 SNOMIAN3 QNV IViOi
SNOISSIW3 idOdMIV
CO O
co t
vvl I
O
CT>
O>
g
cr
Lul
>-
O
O
CM
O
o
o
OD
SNOISSIW3 SNOdlAN3 ONV IViOi
SNOISSIW3
CO
II
co o
CO P-
\|
O
er>
CT>
-
o
in
o
o
ro
O
\f>
CM
O
lf>
O
CM
f--
o2!
SNOISSIW3 SNOHIAN3 QNV IViOi
SNOISSIW3 idOdHIV
o
CT>
CTi
f
t/1
g
H
uo
00
H
Pi
-------
(D
P
O
P
O
(D CTl
rH CTl
Oj
P HJ
5 c3
H
t..| ri
P 0
P OO
<< CTl
CO
Pi "
o to
H t~-
10 CTi
CO rH
d
fS O
<4H
P
§ CD
P -H
rH O
rH P
O pj
-H fl
Ctf rH
rH
O 00
rH 0)
bO O
$ ^
O
CD 00
r~|
P m
o
O CO
CD
CO pj
CD >.
bOH
03
£ ^
CD O
U -H
rH rH
PH ^*
J
;
ox
0
CTl
rH
O
OO
CTl
rH
to
t\
CTi
rH
U
O
CTi
CTl
-H
O
OO
CTl
rH
ro
r--.
CTl
rH
8
O
CTl
CTi
rH
O
OO
CTi
rH
to
CTl
rH
j
!3
H'
CD
f^
E-i
CD
O
W
CTl ** rH C~~
"* vO CTi i 1
VO rH
l>- O rH rH
LO 1^- rH CM
* to
rH
CM
CTl
CTl
LO
OO
VO CM rH CM
OO VO 00 to
to ^~
I 1
vO
CTl
«* OO rH "3-
* CM CM
C-- rH
t^
CTi
00
CTl VO O LO
.
CM CTl OO
VO rH
0
rH
CTi
O CM ^ rH
CM [^ LO rH
LO tO
r-
LO
CTl
t-~ VO LO CM
tO CM rH rH
CM rH LO
0
CTl
CO
O vO OO VO
tO CTl LO T-H
i 1 vO
O
0
CTl
i 1 vO vO LO
^HT ^" LO CM
OO
00
VO
CTi
OO
rt
CD
rj CO
^ Q) 'i-l CO
rH rH ,-J p
Oj << O
C X H
CO O CD rt
P -H rH Jg pj
C P -H T) O
H OS X) CS !H
g g g g
?H ^H f-4 ?H
H -H -H -H
t> J> t> ^
G £ C C
w fl w w
* tO CM
l>!
t-^ tO rH
to
rH
CTl
r-I
rH
^
rH
LO tO lt
to
CTl
to
O rH CM
^t" vO
to
0
rH
OO
rH rH t>-
IO LO
O
0^
vO
oo rq CNI
to
K)
^-
CTl
O VO tO
0
rH
o
rH
rH
K)
rH f-- CM
CTi
O
0
rH
LD
t^~i r~^ *^"
CM
M
0)
rH
H rH
00 O CTJ
CD O P
H S O
P H
H -d
rH S P
H 3 r<
q o o
rt fn p^
PH C3 H
P -H
P P m H Oj
O O r<
r-^ JH JH
'^ '-^ '-^
VO
to
OO
o
00
r~-
to
oo
^O
rH
«
0
OO
^.
CTl
t--
LO
O
oo
VO
rH
^t
rH
00
f\
i 1
VO
CM
r>^
CM
00
g^
n'P
oo oS
00 CD
^ "****«v
W oo
rH O
C^ -4-^
H-H
l1^
rH
P O
-------
130
is steep enough to lessen the beneficial impact of the emission standards.
For the majority of the airport sources, however, no emission controls become
effective in the 1973-1980 time span. Change in the aircraft fleet mix to
one dominated by jumbo and medium range jets does not prevent substantial increases
in aircraft pollutant emissions by 1980. With emissions from environ sources
maintained at nearly steady levels or even declining, these increases in aircraft
emissions are translated directly into increased importance for aircraft among
sources in the region. Airport facilities are not significantly large pollutant
emitters, with the exception of fuel tank farms that become increasingly important
sources of hydrocarbons. Between 1973 and 1980 the portion of the regional
emissions accounted for by the airport increases by a factor greater than 2.
TABLE 32. Definitions of Source Types in Terms
of Specific Inventory Elements
Source Type
Sources Included
Environ Points
Environ Stationary Areas
Environ Mobile Areas
Environ Roadway Lines
Airport Facilities
Airport Ground Mobile
Aircraft
Large point sources included in Georgia Depart-
ment of Natural Resources inventory.
Space heating for residential, commercial, and
small industrial units; hydrocarbon evaporation
from gasoline handling, dry cleaning, and sol-
vent use; waste incineration; and clusterings
of sources in the Georgia DNR inventory.
Traffic on local streets and on freeways more
than about 3 km from the airport.
Traffic on freeways and major arterials near
the airport.
Space heating of airport buildings; aircraft
maintenance and repair; and fuel storage in
tank farms at the airport.
Access traffic to airport facilities and parking
for airport traffic.
Aircraft and directly related equipment in-
cluding ground service vehicles and ramp area
refueling facilities.
-------
Between 1980 and 1990, imposition of controls on the emissions of
aircraft engines arrests the growth of airport emissions. New aircraft
engine standards have effect not only on the aircraft emissions, but also
on emissions from airport facilities through reduced emissions from aircraft
maintenance and testing activities. For the baseline case, an absolute decline
in carbon monoxide and nitrogen oxide emissions between 1980 and 1990 is the
result. The increase in emission of hydrocarbons at the airport between 1980
and 1990 is in large part due to losses associated with refueling operations
in the ramp area and evaporation from large storage tanks. In spite of the
beneficial effects of the aircraft engine standards, the airport emissions
will be a slightly larger portion of the regional totals for carbon monoxide
and hydrocarbons in 1990 than in 1980, exceeding 10% of the regional emissions
for both pollutants. Nitrogen oxide emissions at the airport, however, should
be reduced both absolutely and in relation to other regional sources in the
decade of the 80s.
Also shown in Fig. 35 are the effects of engine shutdown and air-
craft towing strategies for reducing aircraft emissions. The engine shutdown
strategy has been assumed to be applied in the same manner as during the test
period of December 1973. It is effective only for inbound taxi operations and
is participated in only by B-727 and DC-10 aircraft among those operating in
1980 and 1990. Engine shutdown produces a small decrease in airport emissions
of carbon monoxide and hydrocarbons and a negligible increase in nitrogen
oxides. Aircraft towing produces a much larger decrease in emissions than
does engine shutdown, although it is only about 5% in airport nitrogen oxide
emissions. The introduction of new aircraft engine standards by 1990 makes
the towing strategy slightly less effective by bringing aircraft taxi emission
rates and towing vehicle emission rates closer together. It should be noted
from Fig. 35 that aircraft towing is not sufficient to prevent 1980 airport
emissions from being larger than the 1973 baseline. The airport will assume
a larger role in regional air quality by 1980 even if aircraft towing were to
be used.
7.3 STRATEGY IMPACT ON AIR QUALITY
The concentrations of pollutants at several airport and regional
locations have been calculated for the two sets of meteorological conditions
-------
132
used for the studies based on the 1973 source inventory. From these results
it is possible to describe representative trends in air quality levels that
would accompany the development scenario chosen.
7.3.1 Airport Air Quality
Two of the airport activity locations that were shown to be most
sensitive to aircraft operational control strategies in Tables 20-22 are the
aircraft ramp area at the terminal and the central fire station along taxiway
C. The changes in pollutant concentrations calculated to occur at these two
sites through 1990 are displayed in Figs. 36 and 37.
In the aircraft ramp area the dichotomy of wind directions between
the typical summer and fall meteorological sets comes to be associated over
time with distinctly different levels of pollutant concentration. In 1973 the
baseline carbon monoxide and nitrogen oxide concentrations in the ramp area
are roughly the same in summer and fall, while the summer HC concentration is
about twice that occurring in fall. The sources that are important at the
ramp area are different in the two cases, however. With wind nearly out of
the north, the fall meteorological set makes terminal access traffic and
automotive parking and the major concentration of regional sources centered
in the Atlanta CBD important for air quality levels at the ramp area. When
the wind comes from the southwest, as in the summer, aircraft activity assumes
primary importance for the air quality levels at the ramp area. The relative
changes from 1973 to 1980 between automotive traffic emissions and aircraft
emissions generate the air quality trends shown in Fig. 36. By 1980 air quality
levels are definitely higher in the summer for all three pollutants, following
the trend to increased relative size of the aircraft emissions. Retarding
of the growth of aircraft emissions particularly of carbon monoxide and nitrogen
oxides that will accompany the transition to new engine emission control standards
in the decade 1980-1990 is also reflected in the distinct flattening of the
summer growth curves for that period. Fuel storage areas are present both
north and south of the aircraft ramp area and lessen the contrast between the
changes in summer and fall for hydrocarbon concentrations. Perhaps the most
important observation to be made from the baseline curves in Fig. 36, howevers
is that pollutant levels in the ramp area continue to rise regardless of wind
direction. For hydrocarbons and nitrogen oxides, these rises proceed from le.els
which already present problems with regard to ambient air quality standards,
-------
IV
o
o
o
o
o
CO
o
o
u?
2 °
o o
^- cvi
o
o
o
o
rO
o
CD
CD
o
CD
cr>
cr
«x
UJ
>-
O O
o o
CNJ
ro
f-
o 22
ON
' NOIiVdlN30NOO XON
o
cr>
3
o
Oj
0)
1M
0
O
o_
"
0
O
p_
~
O
CT>
CD
O
CO
CD
CC
ro
i»-
o 2?
' NOIlVyiN3DNOD OH
rt
fn
a
H
g
H
(D
I
'NOIlVaiN3DNOO DM
o
o
o
o~
O
CT>
CD
CC
-------
134
o
o
rO
7T
O
O
CM
O
O
NOIiVdiN30NOD XON
o
ID
' NOI1VM1N3DNOD XON
O
o>
a>
cc
O ii i
rO
r--
o <£
O
a>
CTl
t
ti
4-1
CO
s
H
ec.
UJ
3E
=3
CO
O
O
o
o
o
ID
NOIiVdlN3DNOD OH
o
cc
O
O
CO
o
o
ID
O
O
O
o
CJ
o
o
CD.
o o
o
10
o o
o o
O ID
i NOIiVdiN33NOD 3H
o
o
rO
O
O
CM
o
01
o 5?
o
«T>
a>
o S
oo >.
o H:
o
rt
fn
+->
S
u
<
0)
p
P
ed
in
O
JH
P
g
O
s
to
bO
H
' NOIiV«iN3DNOD OD
C-UI/6T/ ' NOIiV«lN3DNOD 03
-------
The factors that influence the changes in baseline concentrations
in the ramp area also explain the effects of the two control strategies
tested. Engine shutdown effects a small change in concentrations only for
summer conditions during which aircraft taxi emissions are a dominant factor.
Towing produces a much larger change and, likewise, is more effective for
summer conditions. Towing is most effective in controlling CD concentrations,
which, however, do not represent serious problems over the time span examined
here. The changes in HC and NOX produced by the towing strategy are appre-
ciable , but, nevertheless, are insufficient alone to bring these pollutants
within standards in the ramp area.
Pollutant concentration trends at the central fire station can
sionilarly be analyzed by considering the changes in emissions from the source
types that are dominant for differing wind directions. It is sufficient to
note from Fig. 37 that the increases in summer concentrations caused by
growth in aircraft activity between 1973 and 1980 are largely counteracted
by the combination of new aircraft engine emission standards and continuing
decline in automotive emissions from 1980 to 1990. For fall, a mixed set of
circumstances makes the temporal patterns less repetative among the three
pollutants. Aircraft taxi-idle makes a small enough contribution to the fall
CO levels for the trend to resemble that of the environs. Takeoff and landing
do have greater effect, however, causing the nitrogen oxide levels to follow
aircraft NOX emission trends. Hydrocarbon emissions from the tank farm that
is immediately upwind of the fire station in the fall overwhelm contributions
from all other sources and cause the only worsening conditions in the period
from 1980 to 1990 for the cases considered. Hydrocarbon levels would seem
to be the major air quality concern at the fire station through 1990.
Control strategies generally have the expected results. Engine
'uitdown produces small changes, at best, and towing is not especially
effective for fall conditions. The towing strategy in the summer, however,
greatly reduces carbon monoxide and hydrocarbon contributions from the out-
-jnd aircraft passing by the fire station on taxiway C.
7.3.2 Regional Air Quality
Pollutant emissions from environ sources were shown to remain
nearly steady or decrease between 1973 and 1990. This should raise the
-------
136
prospects of generally improving air quality in the region. But how will
the substantially increased emissions at the airport affect air quality at
downwind locations? A representation of the answer is given by Tables 33-35
that list the pollutant concentrations at three locations directly downwind
of the airport.
Pollutant concentrations produced by environ sources do indeed
decrease with time at the three locations. Reductions in concentrations from
environ sources occur over both time intervals at all three locations for all
three pollutants and range between 42% and 65%. For the 1973 to 1980 interval,
however, the increase in baseline airport emissions is great enough to cause
the total concentrations to increase in every instance. The fractional increases
in total concentrations decrease with distance from the airport, but except for
CO, they are still substantial 14 km away. Improvements in CO and NOx levels
take place between 1980 and 1990 as a result of reduced aircraft emissions.
Hydrocarbon levels, which present the greatest cause for concern, unfortunately
continue to rise throughout the second time interval. Although the NOX levels
appear to be quite high, calculated annual averages will show that no single
regional location lies directly downwind of the airport often enough for the
NOx air quality standard to be exceeded.
Of the two aircraft emission control strategies examined, towing
has much the greater effect on downwind pollutant concentrations. The con-
sistently small improvements in CO and HC levels caused by engine shutdown
represent only minor alterations of the basic trends in air quality levels.
Towing, on the other hand, produces a reversal of the baseline trend of
increasing CO levels between 1973 and 1980 for locations 6 km and 14 km
downwind. It is less effective for controlling HC and NOx levels which
follow the baseline trends, although at significantly reduced levels. Even
with the towing strategy in effect, hydrocarbon levels at locations close
to the downwind edge of the airport are high enough to be of concern. Control
of fuel handling emissions must be part of any strategy that attempts to
reduce hydrocarbon levels near the airport.
Trends in total pollutant concentrations indicated by Tables 33-35
are displayed as the Fall curves in Figs. 38-40. Also shown are similar
curves that describe downwind concentrations for the summer, when the wind
is from the opposite direction. At great enough distance (e.g. 14 km in
-------
Oj
o
Ol
Ol
rH
O
4~>
p
o
o
n-j
.s
g
[5
a
8
4-1
O
10
O
H
1 ^
rt
p
rt
(U
u
P!
o
o
rH
0}
P;
0
rH
60
0)
r~H
Co
LL,
.3
0)
60
1
to
to
oi
0)
^~"
nit
S
0)
e
o
L)
CO
1 1
to
r-t
Q
^
|
5
Q
0
01
Ol
rH
O
OO
01
i 1
to
Ol
o
Ol
Ol
rH
O
OO
Ol
rH
to
t~^
Ol
rH
O
Ol
Ol
rH
O
OO
Ol
rH
to
[-~.
Ol
,j
0>
0
1
CO
£>-»
DO
C.)
4-*
oj
5 t
p
CO
rH CM tO
OO LO tO
rH CM
Ol LO Tt
("~i t^Q f^s.
rH rH CM
OO LO (O
Ol *O \O
rH CM
OO CM O
Ol LO LO
Tf LO
CM tO LO
Ol CM rH
t~~ OO VO
CM rH -vf
O ^f "5f
rH O rH
rH tO ^f
rH rH
CM tO LO
LO \O rH
rH tO LO
rH rH
-* rH LO
rH * LO
tO LO OO
Pi P
P ^
5-H O rH
H PL, oi
> H P
Pi -rj 0
w <; H
(U
Pi
H
rH
r7 P
C -H O
W O
rH Tf LO
Tl- Ol tO
rH Ol rH
tO rH LO
Pi P
0 rH
5-1 O rH
|H CL, oj
q -H o
fl
-------
138
o3
0
cn
rH
O
-P
-P
o
d
<£
M-t
O
r^
.5
is
Q
Q
QJ
|"H
m
o
a
o
H
P
OS
P
d
53
o
3
1
Q
H
00
0
rH
rH
Ctf
(X,
c3
H
Ci
bO
to
w
-*
nd
g
PH
t 3
^^
0
I
£_4
M-l
0)
O
|
(/)
H
Q
""^
.S
g
^
Q
f-5
r:2
rl-
rH
O
CTi
CTi
rH
O
00
rH
to
t\
CTi
rH
J
vO
0
CTi
CTi
rH
0
00
CTi
rH
to
t\
CTi
rH
pi
^C^
(XI
O
cn
rH
O
oo
cn
rH
to
f-v*
CTi
rH
0
U
1
fe
0
ctf
$H
P
CO
LO tO OO
rH rH CM
rH O rH
rH rH
CTi ** IO
to CM vo
rH 00 CTi
O LO LO
LO t^- CM
CM CM LO
C*-- CD C"^
\O rH t^
rH t-- 00
CM CM
t^ OO LO
CTi CTi CTi
rH rH tO
CM CM
to t\ o
\O OO LO
tO F-. rH
rH
O tO CTi
»
LO oo to
rH VO 00
LO LO
CM ^t- vO
CTi CTi OO
rH t~~ CTi
^J- *H^
C~- LO CM
CT) rH rH
to to r~-
CM CM
10
d P
2^H
O rH
H CL, 03
> H -P
d -H o
W < H
O
d
H
rH
0
10
o3
PQ
LO CTi <*
rH CT) rH
rH CTi rH
rH
CTI 0 CTi
tO rH *
rH OO CT)
O LO LO
LO O rH
CM CM LO
f-- CT) VD
O *JD tO
rH vD OO
CM CXI
t~^ *^~ rH
CT) LO LO
rH rH tO
CM CM
to vo cn
\O LO rH
to r-- rH
rH
\O *zS~ O
LO LO rH
rH LO t^
LO LO
CM tO LO
CTi >-O LO
rH VO OO
^t" ^"
t^. cn vo
CTi rH rH
tO CM vO
CM CM
10
d P
0 rH
rH O rH
H Qi 03
^ rH ^ i
d -H o
H < H
g
O
P
tJ^
CO
0
.5
00
w
LO 00 tO
rH tO LO
rH 1-- OO
cn o cn
to TJ- t^-
rH LO - rH 00
CTi VO LO
tO OO CM
I 1
a p
0 rH
rH O rH
H OH rt
> PT P
OX)
5
^
Q
E-H
0
bO
Co
rH
CD
rt
H
rCJ
1
I 1
CO
.£_
bfl
^j_
.3
t/j
d
0
H
03
rH
i
u
d
Q
u
rH
rH
<,
CtT
-------
1.39
rd
0
Oi
Ol
i i
O
4->
-p
rH
o
&
^
m
o
13
s
rH
Fg
a
X
o
z:
m
o
CO
g
H
P
nJ
rH
p
Pi
CD
o
Pi
8
CJ
rH
aj
s
0
H
W>
S
M-K
rH
rH
aj
U-,
.5
1
Td
a3
PH
J
<
CD
^
e
5
^
HH
CD
(J
P
CO
H
a
t3
c
H
1
g
1
s
,s
^~
rH
o
Ol
01
rH
O
OO
Oi
rH
to
r-
Oi
rH
g
-^
*^o
O
Oi
Ol
t 1
CD
OO
01
F"H
to
r
01
rH
e
,5
CM
O
Ol
Ol
rH
O
00
Ol
rH
to
t-~-
Oi
^H
CD
U
S
0
CO
X
00
CD
P
aj
rH
p
CO
to r- o
t^- rH Oi
rH tO -3-
Ol vO LO
cxi -3- r
CM «tf- vo
01 r~~ vo
Oi rH rH
CM rH ^t
(VJ \O 00
5J- O) tO
cxi r-- o
rH
to Oi CXI
rH OO O
to o *t
J I
r^ r^
oo r-x LO
xt OO tO
x± cxi r
^t- OO CM
O OO Ol
to r~- o
rH CM
r~- to o
O \O to
to to r~-
CXI (XI
CD CTi Oi
to ^f t-~
LO v£) rH
t~H
CO
a -P
0 M
rH O rH
H OH OS
> rV P
C -H 0
W < H
0)
c
H
rH
- \O
CX] "* Is-
(X| -xt \D
Oi t-- O
Oi rH rH
CM rH «*
(XI O CXI
* rH LO
CXI 00 O
rH
tO to vD
rH Ol O
tO CD <*
, 1 1
^^ r^
oo r LO
xt OO tO
^1- CM r-
«* to r-
o to to
tO OO rH
rH CXI
t^ Ol vO
\o r-- *
to to r
(XJ CXI
CD CD CD
to LO oo
LO \O rH
t~H
CO
Pi p
0 rH
rH O rH
H CL, rt
> rV -P
C -rj O
W < H
s
O
FT-*
^J
+J
3
X
(/>
0)
.s
M
p|
W
to r-- o
r-- <* CM
rH CM rt
Ol Ol OO
(X) LO OO
CXI tO LO
01 c^~ \o
Ol Oi CTi
cxi to
CM rH tO
Tt Ol to
CM LO 00
to to \o
rH rt LO
tO OO rH
rH
OO rH Ol
* to r--
3" CM *£>
^ rH LO
O 'd- «=s-
tO CM LO
rH rH
t\ r -3-
\O OO LO
to & o
rH CM
0 *d- -ej-
tO OO rH
LO ^1- O
rH
CO
PI p
0 rH
rH O rH
iH CL, CS
> rT 4->
B -H O
W < H
M
S
*g
Q
H
»
CD
SO
03
t.
rH
CD
>
oj
rH
rC
1
rH
*
00
g
\
DO
3-
p|
H
CO
P!
O
H
s
rH
P
PI
S3
a
Q
o
rH
rH
<2
CC
-------
140
o
oo
o
o
8
O
O
rO
7
QC
cc
UJ
>-
H
(Nl
rt
8
I
o o
o o
o o
o o o
000
o o o
~
o o
o o
US TJ-
8
' NOIJ.VH1N3DNOO DH
' NOIJ.VH1N3DNOD DH
o
o
to
o
o
cc
UJ
o
0
£ui/5T/ ' NOIlVHiNSONOD 00
I I
O
O
10
O
O
o
cc
ft
O
co
O
O
ro
O>
' NOIiVcliN3DNOD OD
03
C
O
H
DO
oo
to
00
H
-------
O
IT)
O
o
o
10
o
o
o
CT>
O LU
oo >-
cr>
o
ID
o 5?
o
CTi
CTi
f
£
o
' NOIiVaiN3DNOD "ON
o
o
o
o
o
o
' NOIlVyiN3DN03 DH
o
o
ro
' NOIlVdiN33NOD XON
o
CD
O UJ
oo >-
cr>
O
o
o
o
ro
f~
CT>
' NOIiVdiN3DN03 DH
I
4-i
m
o
<-&
o
t/)
S
§
u
o
o
o
o
o _
o
o
1 II
o
o
(O
/
O uu
o
o
o
o
e\j
o 2
g
H
cr>
bfl
H
' NOIiVdlN3DNOD 00
' NOIiV8iN33N03 03
-------
142
1
cc
O LU
00 >-
o
1T>
o 2
o
01
CTi
a
g
XON
' NOIiVdiN30NOO *ON
0)
an
O UJ
CO >-
O
o
o
ID
O
O
ro
r
o 2
i
H
Id
g
u
' NOIiVMiN30N03 DH
'NOIiVMiN30NOO DH
o
o
CO
8
CO
o
o
o
<7>
en
8O O
O O
rO fO PJ
O
O
f-
o 2
3
rH
i-l
-------
Fig. 40) the airport is essentially a point source, and its impact on downwind
points is independent of wind direction. Higher hydrocarbon levels at 14 km
during the summer than during the fall are caused by increased fuel evapora-
tion losses at higher temperature. For regional locations nearer the airport,
spatial details of the airport become important. The concentrations of fuel
storage facilities near the northeast perimeter of the airport is reflected
in very large HC levels at close in (2 km) downwind locations with a south-
west wind.
The effects of the towing strategy on downwind CO levels is con-
siderable even at 14 km. As seen previously, towing is less effective for
control of HC and NOX levels and, naturally, has no effect on high HC levels
caused by proximity to fuel storage facilities.
7.3.3 Long -Term Air Quality
Annual average pollutant concentrations for 1980 and 1990 baseline
conditions at a number of receptors on and near the airport are summarized
in Tables 36 and 37. The concentrations in these tables can be compared with
1973 concentrations for the same set of receptors in Tables 27-29. Of
greatest significance in the tables are the annual average NOX concentrations
that can be compared directly with the ambient air quality standard.
On the airport, GEOMET Site No. 2 is located at the central fire
station. Table 36 shows that the NO standard there is slightly exceeded
-A.
in 1980, but by 1990 the level is below the standard. For 1980, only
the NOX level at the most remote receptor, GEOMET Site No. 4, is below the
NOX standard. Considerable improvement occurs between 1980 and 1990, but
receptors near outbound runways , particularly near runway 8/26 (GEOMET Sites
1 , 7, and 8) continue to indicate NOx levels in excess of the standard.
Long-term NOX concentrations at the regional receptors 4 km to 6 km
From the center of the airport are well below the NC^ standard both in 1980
and 1990. The highest annual NOX level at regional locations was found in both
ars t a receptor in the Atlanta CBD, and it is also well below the standard.
^igures 41 and 42 show regional isopleth maps of annual average NOX levels
.tor 1980 and 1990, respectively.
-------
144
H
o
co
a-.
o
1. 1 ^
%
p
;H
^
r-t
O
i_,
'M
*<
Q
-C
^
r3
C
O
H
rt
f-i
o
u
5
r .
i
^J
P
Cv
13
i <
i 1
(£
o
rt
, 1
3
J
<-
.
vO
to
a
H
r_
'if
r
r
^_
s-.
o
ex
o
0
o
p^
>
i
"
^
^
*
tl
^
>
^
£C
r- 1
iJ
O
H
p
H
1
r-1
o
'<
I t
2
.c
s,
5
.,_
>
5
4_,
O
&
r-
<
^
4-J
,O
r-*
S
O
H
>
.n
?H
f "*
~i
t-~ rr r-- to i o i/>
to .c> cr. to r-- o o LO
cr. "~~* to cr. LO ^ ^ j cr.
4 < i i ,~. ( r- J «rj-
r- i co cr. f i ' <^J "»
^ . f^" «^ fX* 4^. f^~ ^* » V
-r r. d co o co to
- 1 cr. co c. o r i to
LT. t-- CT. LO I"- LO LO
-r ^ J ' ) cr. - i LO
LO co o r ) ~ c; LO LO
co LO to o ' i ' ) ' i *r
to ' J " i ^ ) ~ i
o cr. t -- i LO -T co
r - i -D c. -C. C co t-^
co ' J ^) LO to c co r--
cr. cr. cr. o -r cr.
to
co c: ^ i
o cr. to LO " : to to
^ J O O tO » J O LO
cr tO «rr tO "cr IO O "3-
^j co ^ c co to c;
^ i cr. cr. co cr. o LO
C O co r^ r-- to cc
C. LO > tO «- TT
^3 tO = L-0 ^ t~~ 1C
V.
^~
'u"
^
l^
f^
r ]
O".
^-4
rr
c;
ro
u".
»O
c*
»
-j-
^
^ j
r-
L. ,
^
,._^*
tO
o
"
i-1^.
^
"
*-"
^
fO
J
m
o
'""
"H
Q -
.-
^^ ^
Cl.
^
^>
M
<
^J" LO
10 r-'
O IO
r-
to
lO ^
"^ ""
LO
~r
t-
It
'' i
"~^
LO
lO
t ~-
O r--
' 1 IO
u
"^
^=-
f~;
T "
cr. LO
"" c'
*-^
tt-
^
r ~ i
^ £1;
CC u*~.
r^-* r-^
^ 10
** ) r~^-
«o
i
g
L/% ^
r--'
L-", (-".
»0
3s
*O
O
^^ tn*
*
c
p-
< c
o o
2 0
o
*-» c^
y.
M
o
j£
^*
_£;
e
~
t ;
»
z~
^
{
^-
^/
t:
£.
"E
x
^
j
«' 3
<. ;
* - ^
i-
" Cy
'f-
J. i-
C* O
C >
4! i
rz ^
C- ^-*
y
dr x
G *-
' ^
r^
^.
-------
Oj
0
CTi
CTi
rH
i-H
£
^H
X
H
.a
u
p
rH
0
1*
£
P
P!
0
H
P
Oj
rH
P
P!
(D
0
Pi
0
p
p
^3
rH
rH
So
c^3
rH
&
P
rH
O
£_4
H
rS
P
rH
O
H
^
o
>-<
>i \
rH Pr§
O t ^ ^ '
p
Cu
0) JD
U X
V ±.'~^
LO CTl
CTi tO
CXI tO
t^r-
xf tO
CXJ CXI
oo cxi
^ CD
rH
oo to
CXI LO
OO OO
xt- CTl
OO OO
vO LO
=3-^1-
^f vO
rH CXI
OO CTl
rH tO
rH rH
tO i 1
LO r^
oo r~-
LO OO
rH C^
to LO
LO LO
CTl LO
CXI CXI
to to
LO
to
=t
LO
CXI
LO
o
CXI
CTi
o
oo
LO
rH
S
CTi
O
rH
^
OO
oo
^
LO
vO
CD
to
CXI
LO
rH
CXI
to
o
o
rH
CXI
to
CTi
CXI
rH
rH
CTi
to
OO
to
o
to
CTl
OO
rH
CTi
rH
O
rH
CD
vO
LO
CTl
CXI
to
LO
oo
to
CXI CTi
CTi CTl
CXI CXI
rH
*H-t-
tO CXI
OO CXI
OO LO
CTi
r-- CTi
^^ ^^~
LO VO
to
LO CXJ
OO CXJ
vO LO
CXI [--
CXI CXI
OO rH
CXI
LO tO
tO !>-
t-0
t~- rH
rH tO
CTi CTl
oo r^.
>* 0
* oo
OO CXI
vO
LO LO
LO rH
CXI CXI
to to
LO
OO
to
rH
CXI
to
^
oo
t--
CTi
to
oo
LO
CTi
rH
vO
O
to
rH
CTi
O-
CTi
^
oo
to
LO
CTl
cxi
to
LO
CXI
to
^
^
o
to
CTl
rH
rH
LO
CD
rH
OO
CTi
to
LO
to
vO
i 1
rH
rH
cxi
CTi
LO
CTi
LO
LO
cxi
to
CTi
to
t^
LO
CXI
cxi
CTl
O
CTl
r-.
vO
OO
LO
^
o
CXI
^
to
to
rH
,_,.
CD
CTi
O
to
Tt
LO
rH
CX]
to
I CD
CTi CXI
to oo
rH
OO CXI
rHCTl
to cxi
CTiOO
t-- CXI
O LO
rH
LO *3"
*3" LO
^t- LO
Ttf- CXI
toco
cxi to
CX1LO
CXI rH
r-~ CTi
tOrH
CTi CXI
rHCXl
OCX1
C-- LO
LO r-~-
CX10O
CTi OO
efr LO
CTi tO
o to
rHCXl
0)
H
H
8
CTi
cxi
CTi
^
to
CXJ
o
vO
oo
o
rH
oo
cxi
o
OO
O
rH
vO
cxi
vO
cxi
CTi
^
oo
vO
rH
to
10 to
LO tO
vO CD
rH
Cxi tO
CTi CXJ
CXJ to
i-H CD
vO i 1
to t-~
LO CD
rH t--
O CXI
rH rH
"3- O
CTi rH
LO vO
rH O
CXJ VO
v^" \,O
t^"1-" t^~*
CO tO
00 rt
rH CXJ
>* o
vO 00
CO OO
to i>-
rxj LO
O LO
rH rH
«=T LO
to to
rH «*
COLO
rH
vot^
CTi'*
rxj LO
r-^ vo
rHCTi
LOCTl
or-
00 CTi
to to
CXJ CXI
00 *3"
LOtO
vD f-
cxi to
Cxi vo
r-^ vo
Itl (
O LO
CXI rH
to to
"d- LO
cxi ^
r-- rH
oo cxi
rH
CTirH
to *
vOt--
o
CTi
rH
to
vO
to
to
^
LO
00
CXI
vO
CXI
o
to
^
to
rH
o
rH
to
LO
CTl
^
LO
to
OO
LO
to
o
to
to
LO
o
LO
rH
CXI
CTi
vO
CXJ
LO
to
vO
CXI
CD
CTi
CTi
OO
LO
to
OO
g
p
Oj
O
O -P
H
P O
t^ O j
O
LO
cxi
LO
o
rH
LO
LO
LO
to
to
II
O
oo
CXI
to
CXI
cxi
CTl
CTi
oo
OO
r--
J-4
O
^^
P 0$
cxi
**
II
X
LH
to
I!
LO
VO
X
I
-------
146
ALL CONCENTRATIONS IN yG/M3, ANNUAL AVERAGE
Fig. 41. Annual Average NQx Concentrations under Baseline
Conditions for 1980
-------
ALL CONCENTRATIONS IN yG/M3, ANNUAL AVERAGE
FAYETTE CO,
\
4-
Fig. 42. Annual Average XQx Concentrations under Baseline
Conditions for 1990
-------
148
Although HC levels summarized in Tables 36 and 37 are not directly
comparable with the 3-hr HC standards, annual average levels higher than the
3-hr standard indicate a perennial problem, as noted in Section 6. Annual
average HC levels exceed the 160 yg/m3 value at several airport locations in
both 1980 and 1990. For only one regional receptor does the HC level exceed
160 yg/m3. That receptor is nearly coincident with a paint factory included
in the point source inventory, and the long-term HC level there receives
little contribution from the airport.
-------
1/jo
8.0 AIRPORT PLANNING AND AIR QUALITY
The previous sections have shown that airport operations can and do
have a significant impact on air quality both on the airport site itself and
in adjacent areas. The analyses have shown, within the limitations of the
analytical model used, the need for some form of emission control strategy to
insure attainment of the National Ambient Air Quality Standards. Several such
strategies have been evaluated in this report and others have been suggested
although not studied here. The purpose of this section is to provide an over-
view of the procedure by which airports are designed and operated and to indi-
cate where air quality control strategies might be incorporated into the overall
plan.
8.1 THE PLANNING PROCESS
The planning of an aviation facility or group of facilities is an
exceedingly complex task owing to the multitude of interested groups, varying
requirements, and multifaceted implications of air transport. The federal
government early recognized the national significance of aviation and the Civil
Aeronautics Act of 1938 was a first attempt to systematically evaluate airport
needs and to provide some vehicle for federal financial assistance to airport
development. Passage of the Federal Airport Act of 1946 led to the generation
of the National Airport Plan (NAP) , which was an identification of a set of air-
ports throughout the country that were of sufficient importance to be considered
for federal funding of development projects. The NAP underwent some evolu-
tionary changes, with a significant shift in focus coming from the Federal
Aviation Act of 1958. This act defined the role of the Civil Aeronautics Board
(CAB) as the air transportation regulatory agency and established the Federal
Aviation Administration, which was to be responsible for promoting civil aviation
r>nd establishing safety and air space utilization regulations. At this point
' he NA began to take on a longer time horizon and consideration was being given
to projecting future airport requirements as well as current needs. The Airport
and Airway Development Act of 1970 represents the most recent significant
aange in the airport planning process. (A concise history of airport planning
is presented in Ref. 22.) As currently practiced under the guidelines of the
1970 Act, airport planning operates on three fundamental levels: system plan-
ning, master planning, and development planning. System planning takes place
on national, regional, and local scales.
-------
150
8.1.1 National Airport System Plan
By mandate of the Act, the Federal Aviation Administration is respon-
sible for the preparation of a National Airport System Plan (NASP). This plan
replaces the National Airport Plan and is designed to determine national civil
aviation needs both current and extending ten years into the future. The NASP
is to be revised on a regular basis and its development is to be coordinated
with other federal agencies to provide a plan that is consistent with total
transportation requirements. Airports included in the NASP are those that
serve public aviation needs (as opposed to those serving local interests only)
and they must be considered in relationship to other means of intercity
travel and in the context of the total airport environment, not the air-
field only.
The NASP serves as a guideline to the Congress and to the FAA in
the awarding of funds under the Airport Development Aid Program (ADAP). Air-
ports must be included in the NASP to be eligible for ADAP funding, although
such inclusion does not guarantee that funds will be available. In the NASP,
airports are grouped into primary system, secondary system, and feeder system
categories based on the number of enplaned passengers. Annual enplanements
totaling 50,000 and 1,000,000 divide the three classes. Each class is sub-
divided into high, medium or low density groups based on aircraft activity.
Table 38 summarizes the classification system.
TABLE 38. Airport Classification System for
National Airport System Plan3
Airport
Category
Annual Enplaned
Passengers
Annual Aircraft
Operations
Primary System More than 1,000,000
High density More than 350,000
Medium density 250,000 to 350,000
Low density Less than 250,000
Secondary System 50,000 to 1,000,000
High density More than 250,000
Medium density 100,000 to 250,000
Low density Less than 100,000
Feeder System Less than 50,000
High density More than 100,000
Medium density 20,000 to 100,000
Low density Less than 20,000
Reference 23
-------
All existing airports receiving airline service certified by the CAB
are included in the NASP. New and replacement airports that provide air
carrier service are also included. Regional airports that provide service
to more than one community are incorporated along with public-use STOLports
(Short Takeoff and Landing) and heliports. General aviation facilities are
evaluated on the basis of their interface with public civil or military avia-
tion needs prior to inclusion. Table 39 gives a summary of the current National
Airport System and projections to 1982. Of significance is the large increase
in the high density, primary system airports.
TABLE 39. National Airport System, 1973-1982
a
Airport
Category
Primary System
High density
Medium density
Low density
Secondary System
High density
Medium density
Low density
Feeder System
High density
Medium density
Low density
Total :
1973 Number
of Airports
12
14
28
31
185
174
61
795
1,940
3,240
1982 Number
of Airports
50
30
25
253
250
342
193
1,706
1,800
4,649
Reference 24
*. 1.2 Local Airport System Plans
The regional, statewide, or metropolitan system planning process is
1< signed to "determine the extent, type, nature, location, and timing of air-
j/ort development needed in a specific area to establish a viable and balanced
system of public airports. It includes identification of the specific aeronau-
tical role of each airport within the system, development of estimates of
system-wide development costs, and the conduct of such studies, surveys, and
-------
152
other planning actions as may be necessary to determine the short-intermediate,
and long-range aeronautical demands required to be met by a particular system
23
of airports." One of the significant features of the Airport and Airway De-
velopment Act of 1970 is that is provides for planning grants, riot to exceed
2/3 of the project cost, to planning agencies for the preparation of a system
plan.
Under a system planning grant, all work related to the generation of
aeronautical demand forecasts for a region and the development of a plan to
satisfy those demands are eligible for funding. Typical of the types of efforts
that are included are: inventory of airports, aeronautical activity, land
use plans, socioeconomic factors, financial resources; forecasts of aviation
demand in terms of airport users, air traffic activity, fleet mix; capacity
analyses of airspace, airfields, terminals, ground access; determination of
airport requirements and alternative systems to meet the demand; schedule of
25
plan implementation and development costs; management plans. Detailed plans
for individual airports are excluded at this level.
In awarding grants, priority is given to system plans that are a
part of a Department of Housing and Urban Development planning program (e.g.,
as under the Comprehensive Planning Assistance Program authorized by Section 701
of the Housing Act of 1954) and/or are part of a comprehensive multimodal
transportation planning effort. The emphasis is given in an attempt to
integrate airport planning into a total regional planning perspective.
8.1.3 Airport Master Plans
Master plans are designed to present an overall development program
for an individual airport and the land uses adjacent to the airport. Under the
1970 Act, public groups are eligible for master planning grants, also limited
to 2/3 of the total project cost.
9 f\
The master plan is made up of four phases. The Airport Require-
ments Phase consists of the following: an inventory of existing facilities,
socioeconomic data, other planning efforts, financial resources; a forecast
of aviation demand for the airport; a demand/capacity analysis for the air-
field terminal, ground access; a facility requirement determination; a study of
environmental implications of the airport. The Site Selection Phase is the
choice of the location of a new airport. The Airport Plan Phase includes th
-------
development of an airport layout plan to include runways, terminals, navigational
facilities; a land use plan for the airport-owned land and the adjacent areas;
a terminal area plan; and an airport access plan. The Financial Plan Phase
includes schedules of proposed development, estimated development costs, a
study of the economic feasibility of the plan, and a financing program.
Master planning grants are given on a priority basis to airports
experiencing severe operational restrictions, airports in need of congestion
relief, and airports needing expansion to accommodate new equipment or those
experiencing marked environmental problems. Environmental studies, which are
part of the master planning process, are confined to the airport boundaries
to be eligible for grant funds. Studies for the solution of environmental
problems outside the airport and land use planning for the areas adjacent to
the airport boundary are not eligible tasks. ^
8.1.4 Airport Development Plans
The airport development plan is the most specific of the planning
programs. It outlines the details of a specific project to be carried out at
an airport. It represents the final step before blueprints are drawn and con-
struction is begun.
Airport development projects are eligible for federally-assisted
funding under the Airport Development Assistance Program (ADAP). The ADAP
program provides 50% federal funds for all approved programs. Project applica-
tions are given a priority rating based on (1) work essentiality, (2) functional
role of the airport in the NASP, and (3) timing of the need for the project.
Typical ADAP-funded projects include new airport construction, runway addi-
tions and extensions, installation of navigational equipment, expansion of
terminal and cargo facilities, and expansion of entrance and service roads.
5.2 OPERATIONAL PROCEDURES
The operation of an airport, especially a large air carrier facility,
, an >, /,ceedingly complex task owing to the large number of public and private
organizations that must coordinate their activities to provide safe and effi-
ciert airport functioning. Four components of the operational structure can
be identified as being in a position to affect airport operations to achieve
air quality control. They are (1) federal regulatory agencies, (2) state or
local regulatory agencies, (3) airport operators, and (4) airport users.
-------
154
8.2.1 Federal Agencies
The two federal agencies that have the greatest influence on airport
operations are the Civil Aeronautics Board (CAB) and the Federal Aviation Ad-
ministration (FAA). There are other agencies that exert indirect or peripheral
influence but these two maintain prime responsibility.
The Civil Aeronautics Board, as was mentioned previously, was given
the role of an independent regulatory organization by the Federal Aviation Act
of 1958. Its main function is to control air carrier routes, capacities,
and fares. In the highly competitive air transport market, the CAB controls the
level of service between any two points through its certification program. An
airline seeking to establish or discard service along any route must receive
authorization from the CAB. The regulatory process is designed to insure
that all communities that require air transport services will get an adequate
share and that certain high-profit routes will not become saturated with avail-
able seats while other routes suffer chronic shortages. In addition to regu-
lating route capacity, the CAB controls air fares and non-scheduled flight
activity.
The CAB plays a regulatory role in relationships between air carriers.
Mergers, route agreements, and competitive practices are subject to review and
approval by the CAB. The Board has the authority to institute court proceedings
against any aviation organization in violation of its regulations. Board deci-
sions may be appealed to the United States Courts of Appeal, which have exclusive
27
authority to rule on Board orders.
The Federal Aviation Administration is a part of the Department of
Transportation and is a technically-oriented organization as opposed to an
economically-oriented group such as the CAB. The FAA assumes prime line re-
sponsibility for the operation of airports through its mandate to staff and
equip airport control towers. The air traffic controllers are FAA employees
and every function on the airport involving the movement of aircraft must meet
with established FAA guidelines and regulations. In addition, the FAA has
authority to certify aircraft and aircraft engines as to their airworthiness.
Absence of such certification would prohibit the introduction of the equipment
into service.
-------
The FAA assumes the primary role in aviation safety. It has the
ability to issue "rules, regulations, and minimum standards relating to the
77
manufacture, operation and maintenance of aircraft." ' In addition, it cer-
tifies pilots and airports and performs routine safety inspections of air
navigation facilities.
The FAA is active in research and development in improved aeronau-
tical equipment for civil aviation. Aircraft, propulsion systems, navigational
aids, air traffic control procedures and systems and noise reduction are among
the areas of intensive research. The FAA maintains an interface with the Na-
tional Aeronautics and Space Administration (NASA) in this regard.
The role of the FAA in airport planning has already been described.
In some areas the CAB and the FAA play an interlocking role in the
operation of an airport. If, for example, the FAA should determine that con-
gestion at a particular airport is creating an unsafe traffic control situation,
the CAB could be called upon to change its route certifications and force diver-
sion to other facilities. Close cooperation between the agencies is essential
to provide a unified airport operational structure.
8.2.2 State or Local Regulatory Agencies
In some areas a state or local government agency has discretionary
authority over airport operations. In all cases, however, the applicable mini-
mum requirements of the FAA and the CAB must be met.
The agency that has the most direct impact on airport operations is
the airport authority and/or the local government, which has the responsibility
of running the airport within FAA and CAB guidelines. In this case, the local
agency is, in effect, an airport operator. This role is discussed in the next
section.
Some regions have a state or metropolitan aviation department that
serves to set aviation policy for the area. This function lies primarily in
*\e planning realm but the studies, surveys, and recommendations of the agency
:an impact on day-to-day operations. For example, the decision of an agency
to promote alternative airport utilization can foster an FAA or CAB decision
to change operating procedures to accommodate local desires.
-------
156
8.2.3 Airport Operators
The airport operator is responsible for the day-to-day functioning
of the airport activities that are not under the control of the FAA. The operator
may be a private, public, or governmental organization or an individual and is
considered as the chief sponsor and proponent of the airport. He is the
manager of the airport and has the responsibility for airport maintenance, se-
curity, provision and care of public facilities (e.g., parking lots, terminal
buildings, etc.), and financial management, including the collection of airport
user fees and the securing of funds for airport projects.
With regard to operational procedures, the operator must function
within FAA guidelines. Nothing can hamper aircraft or passenger safety and
an operator stands to lose his certification for failure to comply with appro-
priate regulations. In this respect the operator's role is fairly structured
and restricted to established protocols.
The operator plays a major role in airport development and is gen-
erally heavily involved in the planning process, particularly master planning.
In this way, he can influence operational procedures by developing a plan
that will suit his requirements as well as those of other agencies. For
example, an airport authority may choose, in the preparation of a master .plan,
to foster the use of remote parking areas for aircraft, and the plan can be
designed with this feature and still be in compliance with FAA rules.
8.2.4 Airport Users
Airport users include a wide variety of special interest groups all
with the same common interest in making use of the air transportation facility.
Airlines, both passenger and cargo, general and business aviation interests,
passengers, shippers, and commercial service facility operators make up the
heterogeneous mixture of airport users. Each group affects the daily opera-
tional pattern of the airport and each can serve as the focal point of some
form of control strategy for air quality management.
As an example, airlines can determine the procedures that their
pilots will follow within the bounds of FAA guidelines. An engine shutdo1^!
procedure can be incorporated into an airline's operations manual irrespective
of the procedures followed by other airlines at the same airport. The choic
-------
of equipment used on each route can be determined by the airline within the
constraints of the CAB-approved capacity agreements.
Commercial service facility operators such as food service companies,
fuel companies, and the like can determine their own methods of providing
their services. These methods can be developed to minimize air quality impacts;
for example, emission-controlled vehicles can be used on the airport.
8.3 ENVIRONMENTAL ASSESSMENTS
There are several points in the airport planning and operational
procedures where environmental impact assessment must be performed and control
strategies must be recommended in accordance with federal and local law. There
are also numerous points where an assessment and strategy choice can be made
although not required under current regulations. Table 40 lists the principal
air quality control programs and their impact on airport functioning.
8.3.1 Environmental Impact Statement
The Environmental Impact Statement (EIS) has, to date, had the most
direct impact on airport planning. Under the National Environmental Policy
Act of 1969, all federal activities that have a significant impact on the
environment must have an EIS prepared to detail the expected effects. This
requirement affects airport master planning and development planning.
The preparation of an EIS during master planning is an option of the
airport sponsor, with the exception of two situations where it is required: a
master plan study that involves the selection of a site for a new airport
must have an EIS prepared, and any transfer of federally-owned land for civil
aviation use must be accompanied by an EIS. At all other phases of master
planning, environmental review is encouraged although not mandated. Master
,;Lanni g grant funds may be used for the preparation of an EIS for a project
that is expected to have significant environmental impact, and this statement
may serve as the basis for the EIS required under development planning. Grant
aids .annot, however, be used for the solution of environmental problems out-
side the airport boundaries. Likewise, compatible land use planning for the
23
-i adjacent to the airport is not eligible under the grant program.
-------
158
to
p
5H
O
fr
fit
0
CD -M
m ?H
HH o
<3^ O^
r"*
r~(
^^
Co
£_i
bO
X O
P rH
H PH
rH
Ig
p-
^n CD
H bO
< o5
cd
^>*
.
X
^m
P O
10
P; 0
OMH
rH t/)
jj (^
U TO
0 fH
rH P
0
to 0
J>
0 O
P 5n
H PL,
"fr
$-*
O O
MH 4-J
0 0
rH rH
H -H
14H LL^
0 0
p p
to to
3 |3
6 S
p p
Pi Pi
a a
0 0
p p
cd cd
P P
CO CO
bO
Pi
H
r~|
2
CO
rH
PH
5n
0
P
to
1
P
g
E^
i i r ^
CO
rH rH
cd W
| i \ /
0 P
S Pi
2 0
5n 0
H P
> cd
W CO
1
H
a
H
(A
r£*
P
H
^
q
q 0
0-H
H P
P U
cd cd
H
> X
cd pi
rH
H 5H
HMH
U
5n 0
OrH
<4H-H
L| {
rc3
q 0
CO O
rH
X
rH Cd
cd S
0 p
n^t p!
0 0
MH 6
0
P
cd
P
CO
5-i
0
P
to
^
bO
pi
H
to
J3
P
O
cd
H
rH tO
cd '"cJ
0 <4H
P^
2 »->
o £
fn CO
H JH
> bC
Pi
0 fcO
r~j
P -H
CO PI
o 3
H rH
HH CL,
JH
g
H
P
cd
u
H
rH
PH
cd
o
P
rH
O
H
5n
PH
0
rH
H
0
to
PTJ
I/) g
E M I
ppj
0 f i
s ^^
0
p
cd
P
CO
oo
PI
H
§
rH
P t
P
PI
0
pi ,
Q
rH
0
>
a
CO
rH
W
m
0
0
u
cd
rH
PH
.5
rrj
0
rH
H
MH
0
,Q
X
q
O 0
H P
P cd
Cd -H
5n 5n
Cd PH
rH 0
U 5n
0 PH
0
H -H
P
cd
bO
0
CO
I
M-t
O
p
c
^
^
H
cd
p
p
cd
0
p
cti
JH
P
to
q
o
g
op
fi
00
q
H
bO bo c3
q q -H
H-H PH
c S +J
CO TO P-1
r i T 1 CD C
PL, f"^ g Q
£X *H
^ J-H O +- *
CD CD rH CO1
4-> -M CD M
t/) to > CD
W^ Q#
CH
O
H
P
cd
p
C
CD
c«
0
S 1 H
t i CO
0
.1 1 fH
cd co
P rH
COPn
to
rH
O
P
q
0
u
|C~|
bO
g
r~]
P
CO
0*
1^
m
o
P 10
q 0
0 U
2 ^
3 o
cd to
p
p 0
Cd rH
H
0 ^
P O
p q
to O
q
0
CD
Q
00
£
H
P-i
S
CO
rH q
PH 0
H
5n P
0 Cd
P 5H
to 0
!<§*
i \
PH
U
H
q^-'
0
P TO
CdrH
PPn
5H
OrH
P,0
10 5n
f-j 1 J
§ S
HCJ
B-
<< p
Is
u
MH-H
O MH
H
0 q
o Sb
q-H u
CO t/) -H
Pi <-H
0 cd MH
-P cd
q P rH
HUP
cd cd
S rH 0
P rH
Td P U
q cd -H
CO r^H
A 0
P U >
0 ."""I 5n
S Is o
pl 4_j
H t/) O
cd 0 S
P U
P 5n MH
cd 3 O
O
0 to P
H§!
P rH g
t/)<4H Cd
q
0
Q)
Q
txO
d
§d
bO §
3 fQn
Pi
S ^~*
CO S^
i 1 CD
P-H S
pi (
f-H O
CD r-H
-M CD
V) >
S(S
CD
U
5-1
^
o
CO
p
rH 0
H -rH
'q 0
I ( D^
J_j
cd
0
X
1
o
rH
^
O
CO
I
MH
0
0
w
q
0
P
q
H
c3
i
0 T!
P 0
cd -H
P 0
tO pL,
q
J
fl)
H
bO tO
£H C-l
H *rH
Pi f-i
S PI
CO CO
rH rH
CX| (Ii^
S 5-i
0 0
p P
to to
cfr:!
£
i ^
0 CJ'
p <
rT"'
cd bo
S q
H
rX* r_H
j t p
H CO
rH r-H
Cd PH
CD' 0
U
H TO
< q
i
fH
H
cd
'q
Co
-p
MH
cd
5n
O
5n
H
cd
g
0
to
o
H
CO
P
H 00
El a>
rH *H
bO
q q
0 0
H
to +->
H cd
e !-H
0 U
-P
0
^
H
P
cd
^H
0
c§^
t/i
5H
cd
Tii
CH
P
CO
pi
o
H
to
to
H
pi
0
H
bO
^j
w
-------
Since most airport development projects will be funded in part by
the federal government under the Airport Development Assistance Program (ADAP),
an EIS is required at all times. The statement must precede application for
ADAP funding, and, if appropriate, a negative declaration indicating that no
significant environmental impact will be encountered may replace the EIS.
Numerous guidelines have been issued by the FAA, CAB, EPA, and the
Council on Environmental Quality for the preparation of Environmental Impact
00
Statements.
8.3.2 State Implementation Plans
Under the Clean Air Act of 1970, the states are required to prepare
a plan that shows how they will comply with federal air quality standards.
The State Implementation Plan (SIP) impacts on all phases of airport planning
and operation since it must demonstrate attainment of the National Ambient Air
Quality Standards (NAAQS) throughout the state. Any region that cannot be
shown to achieve the NA<\QS must have an appropriate control strategy applied
to reduce emissions. To date, few of the SIPs have addressed airports directly,
because, as has already been stated, airports are responsible for less than 51
of regional emissions. The SIP has impacted on airports through the applica-
tion of control strategies designed to reduce air pollution on less than a
regionwide scale. The three portions of the SIPs that are involved are the
Transportation Control Plan (TCP), the Indirect Source Review, and Air Quality
Maintenance Planning (AQNIP).
A TCP is aimed primarily at reducing emissions from mobile sources
where they contribute to local air quality problems. Several states, in-
cluding California, New York, New Jersey, Pennsylvania, and Texas have incor-
porated emission reduction strategies for airports into their TCP. Control tech-
niques relied primarily on modified ground operations and the strategies were
estimated to result In a 1-10% reduction in CO and HC emissions. Depending on
'he reductions needed to attain the NAAQS, this type of control, if it is as
Jfective as designed, could make a significant contribution to air quality
inanagemei t.
Virports arc one of several types of facilities included in Indirect
Source Review programs. The EPA has mandated that facilities that generate
large volumes of motor vehicle traffic should be subject to an evaluation of
-------
160
whether or not the NAAQS will be violated as a result of the motor vehicle
emissions. New or modified airports with more than 50,000 operations per year
or more than 1.6 million passengers are subject to this review. The review
procedure results in the issuance or denial of a permit to begin construction
or modification. As such, the procedure impacts primarily on airport master
planning and development planning. Regulations for the preparation of an
29
Indirect source review for airports have recently been revised " with a note
that new guidelines will be published shortly.
There is, of necessity, some overlap between the indirect source review
and the environmental impact statement preparation. In an ideal situation the
air quality analysis that is prepared for the one should be adequate for the other.
In some instances the indirect source review may force an EIS effort earlier
in the planning process (e.g., during master planning where an EIS is not re-
quired in all cases).
The Air Quality Maintenance Planning program (AQMP) is designed to
insure that the NAAQS will not only be attained but maintained when regional
growth is considered. As was shown in Phase I of this project, airports
can serve as significant inducers of land development as commerce and industry
locate to take advantage of the improved transportation network, both ground
and air, which accompanies an airport. Airport facilities are, and of necessity
should be, an integral part of the regional planning process and fall, therefore,
under the analyses to be performed in an AQMP program. Airport, system planning
and master planning are ideal points at which to incorporate AQMP analyses
as the focus of both is long-range projections of activity.
8.3.3 Engine Emission Standards
The emission limits promulgated by EPA are the most direct form
of environmental control applied to aircraft and airports. The responsibility
for meeting the standards falls primarily on the engine and airframe manufac-
turers with the FAA playing an overall evaluation role to insure that safety
considerations are not being compromised. The primary impact, therefore, is
on the airport users and hence on airport operational procedures.
-------
8.4
STRATEGY IMPLEMENTATION
The final point to be considered here is where in the airport de-
sign and operation procedures the control strategies studied here can be im-
plemented. Table 41 lists the five control options studied and their most
likely point of implementation.
TABLE 41. Implementation of Air Pollution
Control Strategies on Airports
Strategy
Implementation Point
Engine Shutdown
Towing
Capacity Control
Fleet Mix
lingine Emission Standards
Operations
Can be implemented at an existing air-
port with minimum disruption.
Operations, Development, and Master
Planning
Requires modifications to aircraft
structure, major reorganization of
operations. A new airport could be
designed for this strategy.
National Airport System Planning,
Airport System Planning
Requires consideration of national and
regional air transport needs. CAB
currently has authority to regulate
route capacity.
National Airport System Planning,
Airport System Planning, Operations
Requires consideration of national and
regional air transport needs. Within
CAB capacity regulations carriers have
the option of choosing the aircraft
equipment to use.
Operations
Impact is on manufacturers of engines
and airframes.
The engine shutdown, capacity control, and fleet mix strategies can
be implemented at an existing airport with minimum disruption of normal air-
port operating procedures. The latter two, however, must be viewed in the
-------
162
context of national, or at least regional, air transportation requirements.
The CAB currently possesses the authority to regulate routes and capacities
and could play a key role in the use of capacity control or fleet mix control.
Either strategy would present a major impact on airline economics and must be
thoroughly evaluated prior to implementation.
Towing presents special difficulties because technological changes
would be necessary to accommodate its widespread use. As was previously men-
tioned, current aircraft and tow tractors are not designed for this procedure
and structural refit programs would be needed. Airport operational routines
would have to undergo substantial review to insure safety and to minimize
delays. It is conceivable that an airport might be designed for this strategy
(e.g., with special return taxiways for aircraft with equipment problems, or
with a towing belt on the taxiways).
The engine emission standards represent a strategy that would have
no effect on current airline or airport operations but would require the greatest
technological innovations to realize. New generation engines would be re-
quired to meet the standards, and a gradual phasing in of aircraft equipped with
the new engines mandates that this is a long-term program and offers little
in the way of air quality control in the short term.
-------
9.0 SUMMARY AND CONCLUSIONS
As a result of this program several important conclusions have
surfaced.
Field Test Program
The field test of the engine shutdown strategy at the Atlanta
airport was, at best, inconclusive. Although no operational problems were
encountered, no air quality improvement correlated to aircraft activity
changes was observed.
Observed air quality data was of questionable validity due to the
short test period, equipment difficulties, and the shortage of jet fuel in
the midst of the program.
I^fodel Validation
The Argonne Airport Vicinity Air Pollution (AVAP) model did not cor-
relate well with the observed air quality data collected during the field
test. The problems with the observed data make a conclusive statement about
the model validity impossible.
In general, the model appears to be underpredicting CO concentra-
tions based on a limited validation analysis.
Airport Air Quality
In terms of emission reduction, the application of engine emission
standards has the largest impact of the five strategies tested. It is also
the only strategy to achieve significant NOX emission reductions.
Fleet mix and towing achieve significant CO and HC emission reduc-
tions but the fleet mix change has the disadvantage of substantially increasing
NT0X emissions. Engine shutdown and capacity control show only small emission
reductions.
Under normal meteorological conditions there do not appear to be any
problems with attainment of the National Ambient Air Quality Standards (NAAQS)
for CO. The potential for violations of the HC and NOX standards is evident
with high concentration levels being calculated for these pollutants.
-------
164
None of the five strategies studied is adequate alone to reduce
the HC and NOx levels below those specified by the NAAQS.
Towing, engine emission standards, and fleet mix controls provide
the greatest CO and HC air quality improvements in that order. Only the engine
emission standards provide significant NOX air quality improvement. Engine
shutdown and capacity control provide only small improvements.
Towing derives an added air quality improvement by its alteration
of the spatial emission pattern as well as its overall emission reduction.
Regional Air Quality
The airport has a noticeable impact on air quality immediately down-
wind of it, although the effect diminishes substantially with lateral distance
from the wind line.
There are indications that airport sources are not causing any re-
gional difficulties with attainment of the NAAQS for CO, are causing signifi-
cant problems with the HC standard, and are causing some minor violations of
the NOX standard but confined mostly within the airport boundary.
The airport is roughly equivalent to the Atlanta CBD in terms of
the air quality impact it produces.
None of the strategies alone is capable of insuring compliance with
the HC standard, primarily because of the large concentrations stemming from
environ sources.
The engine emission standards reduce the impact of the NOX viola-
tions to small areas at the ends of the runway and entirely within the airport
boundary.
Growth Impacts
In the period from 1973-1990 regional emissions of CO are expected
to decline dramatically, while emissions of HC and NOX are expected to remain
about constant or increase slightly. The primary trend-setters are the control
of motor vehicle emissions and the increases in vehicle-miles-traveled that
tend to counteract each other.
-------
Airport sources are expected to increase from their current level of
less than 51 of the regional emission total, to around 101 in 1990. The appli-
cation of engine emission standards between 1980 and 1990 arrests the growth
of airport emissions and prevents their increase to greater relative strength.
In fact, the standards decrease the relative magnitude of the airport NOX
emissions between 1980 and 1990.
On the airport, the growth in air traffic will result in increases
in pollutant concentrations at some points (e.g., the ramp area) regardless
of the control strategy applied. At other points (e.g. , the central fire
station), the towing strategy can minimize the impact of the growth although
it is not capable of changing the trends that are being established by the
increase in activity and the application of engine emission standards. Engine
shutdo\vn provides little air quality improvement.
Regionally, air traffic growth and control of motor vehicle emissions
elevate the airport to the position of a bigger contributor to the pollutant
concentrations downwind of it. Towing has the greatest impact on minimizing
the growth impacts, but, with the singular exception of CO, does not change
the concentration trend. For CO, towing does, in fact, result in a different
air quality trend downwind of the airport.
Summary
Based on the above considerations, it appears that the application
of engine emission standards will have the greatest overall impact on airport
and regional air quality. It has the advantage of not requiring any major
disruptions to airport operations and is the only strategy that will effect
NOX emission reductions. Its disadvantage is that it is a long-range solution
and will not provide short-term air quality improvement.
Towing appears to have significant potential in CO and hydrocarbon
control. Its implementation, however, is difficult and costly.
Fleet mix changes have a drawback of increasing NOX emissions. It
woulu probably not be advisable to accelerate the pace of change and hence
permit the application of engine emission standards to newer aircraft in the
fleet.
-------
166
Engine shutdown and capacity control show only small air quality
improvements. Shutdown could be routinely implemented, but the economic
impacts of capacity control would relegate its use only to areas requiring
maximum emission reduction from all sources.
-------
REFERENCES
1. Norco, J. E., R. R. Cirillo, T. E. Baldwin, J. W. Gudenas. An Air Pollu-
tion Impact Methodology for Airports - Phase 1. Report No. APTD-1470.
U.S. Environmental Protection Agency. Research Triangle Park, N.C.
Jan. 1973.
2. Aircraft Emissions: Impact on Air Quality and Feasibility of Control.
U.S. Environmental Protection Agency. Research Triangle Park, N.C.
July 1972.
3. Aircraft and Aircraft Engines: Proposed Standards for Control of Air
Pollution. Federal Register. 37_(239):26488-26500. Dec. 1972.
4. Ground Operation of Aircraft to Control Emissions: Advance Notice of
Proposed Rulemaking. Federal Register. 37^(239):26502-26503. Dec. 1972.
5. Control of Air Pollution from Aircraft and Aircraft Engines. Federal
Register. 38_(136) : 19088-19103. Part II. July 17, 1973.
6. MacWaters, J. T., R. C. Koch, S. D. Thayer. Air Quality Measured at
Atlanta International Airport Before and During Experimental Aircraft
Taxiing Operations. GEOMET Report No. EF-330. June 1974.
7. Review of Atlanta Aircraft Ground Emissions Control Demonstration.
Mitre Corp. MacLaine, Virginia. To be published.
8. Cirillo, R. R., J. F. Tschanz, J. E. Camaioni. Argonne National Labora-
tory. Airport Vicinity Air Pollution Study: The Impact of Modified
Aircraft Taxi Procedures on Airport Air Quality. Report No. FAA-RD-74-212.
Federal Aviation Administration. Wash. D.C. Dec. 1974.
9. Rote, D. M., et al. Argonne National Laboratory. Airport Vicinity Air
Pollution Study.Tteport No. FAA-RD-73-113. Federal Aviation Administra-
tion. Wash. D.C. Dec. 1973.
10. Wang, I. T., D. M. Rote, L. A. Conley. Argonne National Laboratory.
Airport Vicinity Air Pollution Study - Model Application and Validation
and Air Quality Impact Analysis at Washington National Airport. Report
No. FAA-RD-74-132. Federal Aviation Administration. Wash. D.C.
July 1974.
11. Wangen, L. E. , et_ al. Argonne National Laboratory. A Generalized Air
Quality AssessmentTTodel for Air Force Operations - An Operator's Guide.
Report No. TR-74-54. Air Force Weapons Laboratory. Kirtland AFB, N.M.
Time 1974.
12. Rote, D. M., L. E. Wangen. Argonne National Laboratory. A Generalized
Air Quality Assessment Model for Air Force Operations - Technical Report."
Air Force Weapons Laboratory. Kirtland AFB, N.M. To be published.
13. Airport Layout Plan Report, William B. Hartsfield Atlanta International
Airport. Atlanta Airport Engineers. College Park, Ga. Aug. 1973.
-------
168
14. Compilation of Air Pollutant Emission Factors. Second Edition. Report
No. AP-42. U.S. Environmental Protection Agency. Research Triangle Park,
N.C. April 1973.
15. Climatography of the United States, No. 82-9, Decennial Census of United
States Climate, Summary of Hourly Observations, 1951-160, Atlanta,
Georgia. Weather Bureau. U.S. Department of Commerce. Wash. D.C. 1963.
16. Selected Climatic Maps of the United States. Environmental Data Service.
ESSA. U.S. Department of Commerce, p 2-5. Wash. D.C. 1966.
17. Holzworth, G. C. Estimates of Mean Maximum Mixing Depths in the Contigu-
ous United States. Monthly Weather Review. 92_(5):235-242. May 1964.
18. Hosier, C. R. Low-Level Inversion Frequency in the Contiguous United
States. Monthly Weather Review. 319-339. Sept. 1961.
19. Seasonal Combined Wind Distribution by Pasquill Stability Classes (5).
STAR Program, covering the period 1/67 - 12/71 at Atlanta, Georgia.
Prepared for the Georgia Department of Natural Resources. Environmental
Protection Division by the National Climatic Center. NOAA. Asheville,
N.C.
20. Transport Policy Directions. ARC. Sept. 1973 (revised Oct. 1973). The
Atlanta Region: Framework for the Future. An Interim Status Report. ARC.
May 1974. Printed tabulations of calculated results for 1970, 1980, and
1990 of the "null" transportation scenario.
21. Projections of Economic Activity for Air Quality Control Regions. Pre-
pared by the Bureau of Economic Analysis. U.S. Department of Commerce
for the Office of Air Quality Planning and Standards, Office of Air and
Water Programs. U.S. Environmental Protection Agency, p 79. Aug. 1973.
22. Bacon, F., E. B. Perrett, Jr. The National Airport System Plan - Its
History and Its Potential. SAE Paper No. 710414. National Air Transpor-
tation Meeting. Atlanta, Ga. May 1971.
23. The National Aviation System Policy Summary. Federal Aviation Adminis-
tration. Order No. 1000.27. App. 1. March 1972.
24. The National Aviation System Plan, Ten Year Plan 1973-1982. Federal
Aviation Administration. Order No. 1000.27. App. 2. March 1972.
25. Airport Environmental Handbook. Prepared for Department of Transportation
by CLM Systems, Inc. Cambridge, Mass. DOT-05-00059. Aug. 1971.
26. Airport Master Plans. Federal Aviation Administration. Report No.
AC 150/5070-6. Feb. 1971.
27. United States Government Manual 1973/74. Office of the Federal Register.
General Services Administration. July 1973.
-------
28. Nelson, K. E., S. J. LaBelle. Guidelines for Review of Environmental
Impact Statements: Airport Projects. Prepared by Argonne National
Laboratory for the Environmental Protection Agency, Office of Federal
Activities. To be published.
29. Approval and Promulgation of Implementation Plans, Review of Indirect
Sources. Federal Register. 39_(132):25292-25301. July 1974.
30. Air Quality Maintenance Area Designations. Federal Register. 39(133)
July 1974. 39_(156). Aug. 1974.
31. Turner, D. Bruce. Workbook of Atmospheric Dispersion Estimates. U.S.
Environmental Protection Agency. Research Triangle Park, N.C. 1969.
-------
170
TECHNICAL REPORT DATA
(Please read faitsiictioin on the rcurse before completing)
l PI PMX'Q A f
4 TITLE AND SUBTITLE
An Evaluation of Strategies for Airport Air Pollution
Control
5. REPORT DATE
January 1975
6. PERFORMING ORGANIZATION CODE
7 AUTHORIS)
R.R. Cirillo, J.F. Tschanz, J.E. Camaioni
8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Energy and Environmental Systems Division
Argonne National Laboratory
Argonne, Illinois 60439
10. PROGRAM ELEMENT NO.-
11. CONTRACT/GRANT NO.
EPA-IAG-095(D)
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Protection Agency
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This report is the second phase of a program to develop an airport air pollution
impact methodology. This work was coordinated with a field test program at the
Hartsfield Atlanta International Airport involving modifications to aircraft ground
operations to achieve emission reductions. In addition to evaluating the effect of
controls on airport and regional air quality, the airport planning process was
investigated to determine the points at which alternate strategies might be implementec
The principal evaluative tool was the Argonne Airport Vicinity Air Pollution Model
which is a Guassian plume description of pollutant dispersion. The five control
strategies for aircraft studied were: 1) engine shutdown during taxi, 2) towing
aircraft between runways and terminal gates, 3) capacity control, 4) fleet mix control
and 5) engine emission standards. The study showed engine emission standards to
be the most effective overall. Towing and fleet mix control provide substantial CO
and HC air quality improvements, but fleet mix results in a substantial increase of
NOx emissions. Engine shutdown and capacity control provide only small air quality
improvements. The study is designed to provide an insight into the effectiveness of
various control techniques at the Atlanta Airport as well as develop a usable metho-
dology which might be applied to studies at other airports.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
COSATI Field/Group
Airports
Air Resource Management
Planning and Zoning
Land Use
Transportation
Aircraft/Jet Aircraft
Air Pollution Forecasting
Hartsfield Atlanta Inter-
national Airport
Argonne Airport Vicinity
Air Pollution Model
Aircraft Ground Operation:
Airport Air Pollution
Impact Methodology
2 Di3TRItiUT ION STATEMENT
Unlimited
19 SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGE;
153
20 SECURITY CLASS (Tills page/
Unclassified
22. PRICE
EPA Form P22Q-1 (9-73)
-------