FINAL REPORT JULY 1977
AV FR 7029
AIR QUALITY
MAINTENANCE ANALYSIS
IN PHOENIX, ARIZONA
Printed for
U. S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK
NORTH CAROLINA 27711
AEROVIRONMENT INC. 4 145 VISTA AVENUE
PASADENA, CALIFORNIA 91107
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AV FR 7029
AIR QUALITY MAINTENANCE ANALYSIS
IN PHOENIX, ARIZONA
By
Michael W. Chan, Douglas W. Allard, and Sara 3. Head
AeroVironment Inc.
145 Vista Avenue
Pasadena, California 91107
Contract No. G8-02-2349
EPA Project Officer: Rolson Hendricks
U.S. Environmental Protection Agency
Research Triangle Park
North Carolina 27711
May 11, 1977
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This report was furnished to the Environmental Protection Agency by AeroVironment,
Inc., Pasadena, California in fulfillment of Contract No. G8-02-2349. The contents of
this report are reproduced herein as received from AeroVironment, Inc. The opinions,
findings, and conclusions expressed are those of the authors and not necessarily those of
the Environmental Protection Agency. Mention of company or product names is not to
be considered as an endorsement by the Environmental Protection Agency.
11
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ACKNOWLEDGEMENTS
This study was performed with the assistance of the following personnel, besides
the authors, at AeroVironment Inc.
Ms. Diane Barker
Mr. Casey Carter
Mr. Gee Lowe
Mr. Melvin Smith
Dr. Ivar Tombach
Mr. Manley Young
Significant contribution was provided by members of the Phoenix Air Quality
Maintenance Area Technical Operations Committee. Their names, in alphabetical
order, are:
Mr. Arthur Aymar (Arizona Department of Health Services)
Mr. Mike Connors (Maricopa Association of Governments)
Ms. Cathy Digges (Arizona Department of Transportation)
Mr. dames Dorre (Arizona Department of Transportation)
Mr. Gary 3acobi (Federal Highway Administration)
Mr. James Layden (Maricopa County Department of Health Ser-
vices)
Mr. Larry Yeager (Arizona Department of Transportation)
Mr. Edwin Swanson (Arizona Department of Health Services)
Mr. Robert Flinn (Arizona Department of Health Services)
In addition, the following EPA/Region IX personnel provided helpful guidance
during the course of the study.
Mr. Wayne Blackard
Mr. Walter Frick
Mr. Rich Hennecke
Mr. Rolson Hendricks
Mr. Paul 3anicki
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Traffic projections were supplied by the Transportation and Planning Office of the
Maricopa Association of Governments. Current emissions and air quality data were
provided by the Arizona Department of Health Services. Meteorological and additional
air quality data were provided by the Maricopa County Health Department.
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SUMMARY
This report presents results of an analysis for carbon monoxide and photochemical
oxidants in the Phoenix Air Quality Maintenance Area.
An initial 53 control strategies were defined by the Phoenix Air Quality
Maintenance Area Task Force (AQMATF) for study. Of these, 11 strategies were
proposed for evaluation as to their effectiveness in attaining and maintaining the 8-hour
CO and 1-hour oxidant standard. Three basic control strategies traffic system
improvements including highway construction, improved mass transit including transit
incentives, and regional development planning - are part of the ongoing planning process
and, therefore, were assumed throughout the analysis. Two other control strategies
inspection/maintenance and carpooling - are already in operation but were evaluated in
the same manner as the remaining six strategies. The six other strategies considered
for inclusion in the Phoenix Air Quality Maintenance Plan were: periodic maintenance,
vapor recovery, dealer emissions control maintenance guarantee, clean air rebate,
bicycle systems, and work and driving schedule shifts.
For CO, the evaluation was achieved by means of mathematical modeling using
the APRAC-II model as well as by simple scaling. For oxidant, the EPA recommended
approach, known as the Appendix J method, was used (Appendix 3, Code of Federal
Regulations, 40CFR51).
Predictions of severe-case CO readings were made for 1980, 1985, 1990, 1995 and
2000 and interpolated for years in between. The predictions showed that the CO 8-hour
standard would not be attained until 198^ no matter what combinations of the eleven
proposed strategies were implemented. For the 1985 case, the three basic control
strategies (base case) with either periodic maintenance or periodic maintenance and
carpooling would be the only combinations which would achieve attainment of the
standard. In 1990 and 1995, the base case alone would be sufficient to attain and
maintain the standard because of decreasing emissions due to stricter controls on
automobile emissions. However, the reduction would not be adequate to maintain the
standard in the year 2000 and there would again be exceedances. The standard would be
maintained in 1995 and 2000 with the addition of any of the following controls to the
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base case: (a) inspection/maintenance, (b) periodic maintenance, (c)
inspection/maintenance and carpooling, or (d) periodic maintenance and carpooling.
Carpooling alone would not be sufficient to maintain the standard in 2000.
Oxidant air quality projections indicated that, with the three basic strategies, the
oxidant standard would be attained in 1986 and maintained thereafter through 2000.
The implementation of inspection/maintenance, periodic maintenance, carpooling, vapor
recovery or their combinations would expedite the attainment and prolong the
maintenance of the oxidant standard. The earliest year that the oxidant standard would
be attained by any combination of strategies was predicted to be 1981.
Predicted effects from the four strategies of dealer emissions control
maintenance guarantee, clean air rebate, bicycle systems, and work and driving
schedule shifts were not discussed here because they did not provide any significant
contribution to the maintenance of the CO or oxidant standards.
VI
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TABLE OF CONTENTS
Page
ACKNOWLEDGEMENTS iii
SUMMARY v
I. INTRODUCTION 1
II. DESCRIPTION OF THE STUDY AREA 2
III. BASE YEAR AIR QUALITY 5
Photochemical Oxidants 5
Carbon Monoxide 9
IV. BASE YEAR EMISSIONS INVENTORY 18
Traffic Sources 18
Non-Traffic Sources 18
V. PROPOSED EMISSION CONTROL STRATEGIES 22
Description of Proposed Control Strategies 23
Effectiveness of Proposed Control Strategies 31
VI. EMISSIONS INVENTORY PRO3ECTION 34
Projection Methodology 34
Projected Emissions 36
Effect of Implementation of Alternate Control 42
Strategies on Emissions
VII. MODELING OF CO AIR QUALITY 45
Case Selection 45
APRAC-II Inputs 45
APRAC-II Verfication 51
CO Air Quality in 1975, 1985 and 1995 without Additional 56
Control Strategies
CO Air Quality in 1985 and 1995 with the Implementation 60
of Inspection/ Maintenance and Carpooling
CO Air Quality in 1985 and 1995 with the Implementation 64
of Other Control Strategies
Projected CO Air Quality in 1980, 1990 and 2000 68
Predicted Attainment Years for CO 68
A Summary of CO Air Quality 72
vu
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VIII.
IX.
X.
PHOTOCHEMICAL OXIDANT AIR QUALITY PROJECTIONS
CONCLUSIONS
REFERENCES
APPENDIX A -
APPENDIX B -
APPENDIX C -
APPENDIX D -
APPENDIX E -
APPENDIX F -
APPENDIX G -
APPENDIX H -
73
82
8*
Traffic Emissions - Base Year (1975) and
Projections for 1985 and 1995
Traffic Emissions Projections to 1980,
1990, and 2000
Non-Traffic Emissions Base Year (1975)
Non-Traffic Emissions Projections
Effect of Control Strategies
Description of the APRAC-II Model
Major assumptions of the Air Quality
Maintenance Analysis
Glossary
vi u
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LIST OF FIGURES
Figure Description
1 Location of study area 3
2 Boundaries of study area *
3 Meteorological and air quality monitoring locations in the Phoenix 6
area in 1975
it Cumulative frequency distributions for ozone measurements made 10
continuously during 1975 at Locations 1 and 3
5 Typical diurnal variation of ozone at Location 1 in the summer 12
6 Cumulative frequency distribution for CO measurements made 15
continuously during 1975 at Location 1
7 Typical diurnal variation of CO in downtown Phoenix in winter 17
8 Transportation system plan for Maricopa county 24
9 Existing transportation network 25
10 Existing urban districts 27
11 Generalized urban boundaries 28
12 Projected vehicle miles traveled by facility type 35
13 Traffic emission trend through 2000 38
14 Non-traffic emission trend through 2000 ^°
15 Total emission trend through 2000 **
16 Emissions grid map *'
17 Surface weather map at 7:00 a.m. EST on 4 November 1975 48
18 A linear regression plot of observed versus predicted concentra- 53
tions
19 A scatter diagram showing observed data versus adjusted predic- 55
tions
20 Isopleths of predicted 8-hour CO concentrations in ppm for the 57
1975 case
IX
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Description Page
21 Isopleths of predicted 8-hour average CO concentrations in ppm 58
for 1985 without 8 additional control strategies (base case)
22 Isopleths of predicted 8-hour average CO concentrations in ppm or 59
1995 without 8 additional control strategies (base case)
23 Isopleths of predicted 8-hour CO concentrations in ppm for 1985 62
with the implementation of inspection/maintenance and carpool-
ing
24 Isopleths of predicted 8-hour CO concentrations in ppm for 1995 63
with the implementation of inspection/maintenance and carpool-
ing
25 Predicted peak 8-hour CO concentrations in ppm under various 70
combinations of control strategies
26 Required non-methane hydrocarbon emission control as a function 74
of photochemical oxidant concentration
27 NMHC emissions (tons/day) under various control strategies (base 75
case incorporates strategies in regional plan only)
28 NMHC emissions (tons/day) under various combinations of control 77
strategies utilizing carpooling
29 NMHC emissions (tons/day) under various combinations of control 78
strategies utilizing vapor recovery
30 NMHC emissions (tons/day) under various combinations of control 79
strategies utilizing vapor recovery and carpooling
31 NMHC emissions (tons/day) for the base case and carpooling and 80
vapor recovery in addition to base case.
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LIST OF TABLE TITLES
Table Description
1 Phoenix Site Locations and Components Monitored 7
2 Maximum One-Hour Concentrations and Exceedances of the 8
Federal 1-hour Standard for Ozone
3 Number of Exceedances of 1-Hour Ozone Standard by Month and H
Hour of Day at Location 1
4 Peak 8-hour Averages and Exceedances of the Federal 8-Hour 14
Standard for CO
5 Number of Exceedances of 8-Hour CO Standard by Month and Hour 16
Ending at Location 1.
6 Base Year (1975) Vehicle Miles Traveled and Traffic Emissions by 19
Vehicle Type
7 Base Year (1975) Non-Traffic Emissions and Total Emission 21
Summary
8 Changes in Percent Average Daily Traffic with the Implementation 33
of Work and Driving Shifts
9 Projected Traffic Emissions Base Case 37
10 Projected Non-Traffic Emissions - Base Case 39
11 Projected Total CO Emissions under Proposed Control Strategies 43
12 Projected Total NMHC Emissions under Proposed Control Strate- 44
gies
13 Wind Data used for the APRAC-II Simulations 49
1£ Meteorological Data (at Sky Harbor Airport) used to Calculate 50
Atmospheric Stability
15 A Comparison of Predicted and Observed 8-Hour CO Concentra- 52
tions
16 A Comparison of Observed and Adjusted Predictions of 8-Hour CO 54
Concentrations
17 Predicted Severe Case 8-Hour Average CO Concentration at the 61
Monitoring Sites in 1975, 1985 and 1995
XI
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Table Description _
r Page
18 A Comparison of Severe Case 8-Hour CO Readings at the 65
Monitoring Sites with and without the Implementation of Vehicle
Inspection/ Maintenance and Carpooling
19 The Ratios of Peak CO Readings to CO Emissions Derived from the 66
Five APRAC-II Runs
20 Predicted Peak 8-Hour CO Readings in 1985 and 1995 for Different 67
Control Strategies
21 CO Emissions and Peak 8-Hour CO Readings in 1980, 1990 and 2000 69
for Different Control Strategies
22 Years of Attainment of the CO Standard for Different Control 71
Strategies
23 Years of Attainment of the Oxidant Standard for Different Control 81
Strategies
2k Carbon Monoxide and Oxidant Attainment and Maintenance Years 83
XII
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I. INTRODUCTION
Under Section 51.12, paragraph (e), Part 40 of the Code of Federal Regulations
(*OCFR 51.12(e)), which was published on June 18, 1973, all states were required to
identify areas which, due to the air quality at that time and/or projected growth rate,
might have the potential for exceeding any national standards within the subsequent 10-
year period. Analysis performed by the State of Arizona indicated that within the
Phoenix Standard Metropolitan Statistical Area (SMSA) the 8-hour CO standard and the
1-hour oxidant standard were being exceeded. The Phoenix SMSA was therefore
designated as an Air Quality Maintenance Area (AQMA) for carbon monoxide and photo-
chemical oxidants. In May, 1976, an Air Quality Maintenance Area Task Force
(AQMATF) was formed to develop an Air Quality Maintenance Plan to assure that
emissions associated with projected growth and development would be compatible with
the maintenance of the 8-hour CO and the 1-hour oxidant standards.
The primary objective of this study was to assess the effectiveness of emission
control strategies proposed by the Phoenix AQMATF. 1975 was selected as the base
year because that was the year with the latest available air quality and emissions
information at the time this study was begun. Future years for which air quality and
emissions were examined in detail were 1985 and 1995. For 1980, 1990 and 2000, air
quality and emissions information was derived by interpolation or extrapolation.
In the assessment of the 8-hour CO air quality, the APR AC model developed by
Stanford Research Institute and modified by AeroVironment, hereafter referred to as
the APRAC-II model, was used. For oxidants, the approach recommended by the EPA,
often referred to as the Appendix J method, was used (Appendix J, Code of Federal
Regulations,40CFR 51)t
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II. DESCRIPTION OF THE STUDY AREA
The study area is located near the center of the Salt River Valley, a broad, oval-
shaped, nearly flat plain. The city of Phoenix is at the center of the area, with the
cities of Glendale, Scottsdale, Mesa, Tempe, and other smaller communities surrounding
it. The study area encompasses about 4400 square kilometers around Phoenix, which is
at an elevation of about 335 m above mean sea level (MSL). It is located approximately
600km east of Los Angeles, California and 600 km south-west of Albuquerque, New
Mexico. (Figure 1).
The boundaries of the study area were defined by the AQMATF under the advice
of the Maricopa Association of Governments (MAG), whose responsibilities include
planning of regional developments and transportation in this area. Specifically, the
study area is bounded to the north by Pinnacle Peak Road, to the south by Hunt
Highway, to the east by Meridian Road, and to the west by 3ackrabbit Trail (Figure 2).
The study area is protected on almost all sides by mountains. The Salt River
Mountains are located about 10 km to the south of Phoenix and rise to 790 m MSL. The
Phoenix Mountains lie 13 km to the north-northwest of Phoenix and have a maximum
elevation of 700 m MSL. Twenty-nine kilometers to the southwest lie the Estrella
Mountains, with a peak of 1006 m MSL, and 40 km to the west are found the White Tank
Mountains with an elevation of 1220 m MSL. The Superstition Mountains are
approximately 65 km to the east and rise to 1400 m MSL.
The Salt River runs from east to west through the valley but, owing to impounding
dams upstream, it is usually dry. It is joined at the western boundary of the area by the
Gila River from the south, and the Agua Fria River and New River from the north. It is
also joined by the Verde River just beyond the study area from the northeast.
The population of the area in the base year, 1975, was around 1,230,000, of which
over half was located in Phoenix. The area includes many attractions for tourists such
as golf courses, swimming pools and over 500 annual special events from art shows to
rodeos. Arizona State University is in Tempe, just east of Phoenix.
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Black
Consttllilion A Canyon Cily
gggf rV>' *au#3i!
-Tğ?vX ,r i,ğ7JT*\r 10
SCALE OF MILES
0 10 2O 30
Figure 1. Location of study area.
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PARADISE VALLEY
SCOTTSDALE
PHOENIX IV
VAN BUREN STREET
BUCKEYE ROAD I j
APACHE BOULEVARD
SUPERSITITION
AIR QUALITY
MAINTENANCE AREA
CHANDLER
SCALE OF MILES
AEROVIRONMENT INC.
01 2345
Figure 2. Phoenix study area boundaries.
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III. BASE YEAR AIR QUALITY
Air quality measurements were made at eight sites in the Phoenix area in 1975,
the locations of which are shown in Figure 3. Seven of these sites were operated by the
Maricopa County Health Department (MCHD) and one by Arizona Department of Health
Services (ADHS). Table 1 presents the name of each location, the operating agency, its
address, and the components monitored.
Since this study is concerned with oxidants and carbon monoxide, only these two
pollutants will be discussed.
PHOTOCHEMICAL OXIDANTS
Photochemical oxidant (ozone) was measured at six monitoring stations in
Phoenix. At all of these stations, except location 3, ozone was measured by means of
UV photometry. At location 3, colorimetric detection was used from January-August
and UV photometry from September-December. All instruments were calibrated every
six months using the EPA prescribed method of neutral buffered potassium iodide
colorimetric analysis.
Exceedance of the one-hour National Ambient Air Quality standard for ozone
(160 yg/m3) was reported at five of the six sites monitoring this pollutant in 1975.
Maximum one-hour concentrations and exceedances are presented in Table 2. Most
frequent exceedances were reported at location 3, downtown, followed by locations 1
and <*, although location 4 monitored ozone only sporadically.
The highest and second highest one-hour ozone concentration averages reported
during the field program were 298 ug/m3 on 15 3uly 1975 at location 1 and 259 yg/m3 on
30 3une at location 3.
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,,,
SCOTTSDALE
VAN BUREN STREET
PHOENIX
BUCKEYE ROAD
AIR QUALITY
MAINTENANCE AREA
SCALE OF MILES
01 2345
WAEROVIRONMENT INC.
Figure 3. Present meteorological and air quality stations in the Phoenix area. All stations were in operation in
1975 except for location 5. Locations 3 and 7 rennrto^i ajr quality data only. Location 10 reported
meteorological data only.
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Table 1. PHOENIX SITE LOCATIONS AND COMPONENTS MONITORED
Site Name
1 Central Phoenix
Station
2 South Phoenix
Station
3 Arizona State
Station
4 Glendale Station
5 West Phoenix
Station
6 North Phoenix
7 North Scottsdale/
Paradise Valley Station
8 Scottsdale Station
9 Mesa Station
10 Sky Harbor
International Airport
Address
1845 E. Roosevelt
Phoenix
4732 S. Central Ave.
Phoenix
1740 W. Adams
Phoenix
6000 W. Olive
Glendale
3300 W. Camelback
Phoenix
8531 N. 6th Street
Phoenix
13665 N. Scottsdale Rd.
Scottsdale
2857 N. Miller Rd.
Scottsdale
3rd Place and Center
Mesa
Sky Harbor Blvd.
Phoenix
Operating
Agency
MCHD
MCHD
ADHS
MCHD
MCHD
MCHD
MCHD
MCHD
MCHD
NWS
Components
Monitored
CO, CH^, THC,
NO , SO4, 0,,
Part., WS, WD,
and Solar Radiation
CO, Ov SO-,
Part., *WS, WD
CO, THC, NO7, SO?,
O3, Part., WSl WD
CO, SO7, O,, Part.
WS, WCT 5
No monitoring done
in 1975
CO, 03, WS, WD
Part. WS, WD
CO, NO?, O,, Part.
WS, WD7 Solar Radiation
CO, THC, SO-,
Part., WS, WD, T
Surface Weather
Observations
MCHD: Maricopa County Health Department
ADHS: Arizona Department of Health Services
NWS: National Weather Service
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Table 2. MAXIMUM ONE-HOUR CONCENTRATIONS AND EXCEEDANCES
OF THE FEDERAL ONE-HOUR STANDARD FOR OZONE
(160 yg/m3).
Location
1
2
3
4
6
8
Period
Observed
Jan-Dec 75
Apr-Dec 75
Jan-Dec 75
Jan, Apr, May,
July 1975
Jun-Dec 75
Jan-Dec 75
Maximum
1 - Hour
Concen-
tration
fuR/m3)
298
135
259
196
192
192
Hours
Std. was
Exceeded
25
0
53
13
13
1
% Hrs.
Std. was
Exceeded
0.4
0.0
0.7
0.5
0.3
0.0
Days
Std. was
Exceeded
12
0
25
9
10
1
% Days
Std. was
Exceeded
4.7
0
7.5
9.4
5.9
0.4
8
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Figure 4 presents frequency distributions for continuous ozone measurements
made during 1975 at locations 1 and 3. Readings at location 3 are generally higher
except for the highest 0.0^% of the observations. Median (50 percentile) values were 1 5
3 at location 1 and 33 yg/nrr at location 3.
Annual averages at the two sites were 2f ug/m at location 1 and 39 ug/m at
location 3.
The highest monthly averages as well as the most frequent exceedances of the
national standard occurred in summer. Eighty-one percent of the exceedances reported
occurred during the period June through August. A July average of 70 ug/m and an
average daily one-hour maximum of 12* yg/m was recorded at location 3. February,
March, and April experienced no ozone exceedances and relatively low average values.
Table 3 presents a monthly and hourly breakdown of ozone national standard
exceedances at location 1. Most frequent exceedances occurred during August and 72%
of the exceedances occurred during the hours 1100-1500 MST at this location.
Figure 5 illustrates typical diurnal variation of ozone at location 1. Hourly
averages for July are used for this figure. Other months show a similar variation,
although the magnitude, especially of the peaks, is different. An increase in ozone
levels from nighttime values is observed shortly after sunrise, building to a peak at noon
when precursors (NMHC, oxides of nitrogen) have had time to react in the sunshine.
The diurnal variation at location 3 is similar.
CARBON MONOXIDE
Carbon monoxide was measured at seven stations in Phoenix. At six of these
stations, CO was measured by means of NDIR Spectroscopy. At location 3, CO was
detected by flame ionization gas chromatography. The instrument spans were checked
weekly with a dilute CO gas mixture, and EPA audited gas cylinders were used for
multipoint calibrations.
No exceedances of the one-hour National Ambient Air Quality Standard for CO
(40 mg/m3) were reported at any of the monitoring sites. On the other hand,
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r i i i i i i in
1 HOUR 03 STANDARD
,01 0.1 12 10 20 40 60 80 90
FREQUENCY (PERCENT)
98
99.99
Figure k. Cumulative frequency distribution for O., measurements made continuously during
1975 at Locations 1 and 3.
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Table 3. NUMBER OF EXCEEDANCES OF 1-HOUR O, STANDARD BY MONTH AND HOUR OF DAY AT
LOCATION 1. *
Beg.
Hr.
Mo.
Jan 75
Feb
Mar
Apr
May
Jun
3ul
Aug
Sept
Oct
Nov
Dec
Total
By
Hour
0123456789
10
1
2
3
11
1
1
1
3
12
2
4
6
13
I
2
2
5
1*
1
1
2
k
15
1
1
1
3
16
1
1
17 18 19 20 21 22 23
Total
By
Month
3
1
8
12
1
25
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06
Figure 5.
Typical diurnal variation of
standard is 160 Vig/m for one hour
12 18
Hour of Day (MST)
at location 1 in the summer. The ambient air quality
23
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exceedances of the 8-hour standard (10 mg/m ) were reported at all sites measuring
CO, with a higher frequency (over 55 days in 1975) at locations 1 and 3 in downtown
Phoenix. Frequency of exceedance statistics are presented in Table 4.
The highest and second highest one-hour averages were both 40 mg/m reported
twice at location 3 on 13 November 1975. The highest 8-hour average was 34 mg/m on
13 November at location 3 and the second highest was 30 mg/m on % November, again
at location 3.
Figure 6 presents the frequency distribution for CO measurements made
continuously during 1975 at location 1. The distribution at location 3 is very similar.
The median value (50 percentile) at location 1 is approximately 2 mg/m .
Typical one-hour averages at all monitoring stations were below 3.5 mg/m .
Lowest typical values were recorded at location 4 where the highest monthly average
was only 3.4 mg/m . Highest typical values occurred at location 3 where monthly
averages ranged from 1.3 to 6.7 mg/m .
The severe time of the year for CO in Phoenix is late fall and early winter.
Average values during the period November through January at locations 1 and 3 were
3 3
6.1 and 6.2 mg/m respectively, compared to 1.7 mg/m during the period June through
August. Seventy-three percent of the eight-hour national standard exceedances
reported at location 1 occurred during the period November through January (Table 5)
as did 78% of the exceedances at location 3. (It should be noted that little CO
monitoring was done in July at location 3).
Figure 7 shows a typical diurnal variation of CO at location 1 during December
1975. Characteristic peaks occur in mid-morning and evening hours roughly correspond-
ing to the peak morning traffic hours and limited mixing conditions prevalent in the
evening. This pattern prevails throughout the year with only the magnitude of the peaks
changing. Other locations exhibited the same pattern, although during the summer at
some sites the trends were lost as the CO levels dropped to near background.
13
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Table 4. PEAK S-HOUR AVERAGES AND EXCEEDANCES OF THE FEDERAL
8-HOUR STANDARD FOR CO.
Location
1
2
3
4
6
8
9
Period
Observed
1/1/75-12/31/75
1/1/75-12/31/75
1/1/75-12/31/75
1/1/75-12/31/75
1/1/75-12/31/75
1/1/75-12/31/75
1/1/75-12/31/75
Peak 8-
Hrly.
Avg.
(mg/m )
25.8
13.2
33.5
10,9
10.8
14.5
16.5
No.
of 8-hr
Excds.
77
5
97
1
4
14
1*
% Hrs.*
8-hr Std
was
Excd.
9.2
0.7
9.9
0.1
0.1
1.6
1.9
No. Days
8-hr Std
was
Excd.
59
5
69
1
4
13
14
% Days*
8-hr Std
was
Excd.
21.2
2.2
21.2
0.4
1.6
4.5
5.6
* The base for the calculation of percentages includes only 8-hour periods
with at least five hourly observations.
14
-------
1-hour
CO Standard
c
0
+->
£
0
U
100
50
30
20
10
1
S
\
\
\
0.01 0.1 12 10 20 3040506070 80 90 98
Frequency (percent) of exceedance of indicated concentration
Figure 6. Cumulative frequency distribution for CO measurements made continuously during
1975 at location 1.
99.99
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Table 5. NUMBER OF EXCEEDANCES OF 8-HOUR CO STANDARD BY MONTH AND HOUR ENDING
AT LOCATION 1.
Beg.
Hr.
Mo.
Jan 75
Feb
Mar
Apr
May
3un
Jul
Aug
Sept
Oct
Nov
Dec
Total
By
Hour
0
1
1
1
1
3
6
13
1
1
1
1
1
2
1
7
2
2
1
1
1
3
1
1
2
*
2
1
3
5
1
1
1
3
6
1
1
7
1
1
8
2
2
9
1
1
10 11 12 13 14 15 16 17 18
19
1
1
20
2
2
1
5
21
2
3
3
8
22
1
3
3
3
10
23
5
2
1
2
3
3
16
Total
By
Month
16
4
1
1
2
1
0
0
2
10
18
22
77
-------
Hour of Day (MST)
Figure 7. Typical diurnal variation of CO in downtown Phoenix in winter. The ambient air quality
standards are 10 mg/m3 for 8 hours and 40 mg/m for 1 hour.
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IV. BASE YEAR EMISSION INVENTORY
TRAFFIC SOURCES
Traffic emissions for the base year (1975) were derived from traffic link data in
historical record format provided by Maricopa Association of Governments (MAG). The
traffic link data was provided on a magnetic tape and was based on an existing Phoenix
traffic network which incorporated a population of 1.23 million. The information which
was extracted from the magnetic tape for use in computing the emissions included the x
and y coordinates of the beginning and ending point of each link, the length of the link,
the daily volume of vehicles on the link and the link's capacity.
In computing emissions on each link, a program developed by AeroVironment,
called AVSUP5, was used. This program was a modified version of an EPA program,
SUPP5 (U.S. EPA, 1976). Assumptions concerning diurnal traffic distribution, heavy-
duty vehicle mix, vehicle speed, secondary traffic, hydrocarbon reactivity and details of
emission computation in AVSUP5 are presented in Appendix A.
Table 6 presents VMT and motor vehicle emissions of CO and non-methane hydro-
carbons (NMHC) by vehicle type. Light duty gasoline vehicles are obviously the major
traffic source for both pollutants, contributing 65% of CO emissions and 61% of NMHC
emissions on primary links. The fraction of light duty gasoline vehicles on the road
varies from 66% to 78% depending on hour of day and facility type. Emissions from
secondary traffic amount to 14% and 13% of total CO and NMHC traffic emissions
respectively, slightly greater than its 12% share of the total VMT due to a lower vehicle
speed.
NON-TRAFFIC SOURCES
Non-traffic emissions were obtained from Emission Inventory Report for the
Phoenix Study Area (Pacific Environmental Services, 1976). Appendix C presents
methodological and computational details. In general, PES used the 1972 National
18
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Table 6. BASE YEAR (1975) VEHICLE MILES TRAVELED
AND TRAFFIC EMISSIONS BY VEHICLE TYPE
Vehicle Type
Primary Traffic
Light Duty Gasoline Autos
Light Duty Gasoline Trucks
Heavy Duty Gasoline Trucks
Light Duty Diesel Trucks
Heavy Duty Diesel Trucks
Motorcycles
Subtotal
Secondary Traffic
Total
VMT/Day
x 106
11.8
2.9
0.8
<0.1
0.2
<0.1
15.8
2.2
18.0
Emissions
CO
(tons/day)
607.1
182.3
141.7
<0.1
4.0
3.3
938.3
iĞ.Ğ
1086.7
NMHC
(tons/day)
80.0
30.6
19.1
<0.1
0.7
0.9
131.4
20.3
151.7
19
-------
Emissions Data System (NEDS) Summary as a baseline document. This summary was
updated to reflect 1975 emissions. Sources inventoried included gasoline handling,
solvent evaporation, structural fires, industrial incineration, space heating, aircraft
(commercial, civil, and military), railroads, and point sources (industrial and power
plants).
Table 7 presents base year non-traffic emissions based on a population of 1.23
million. The major non-vehicular CO sources are airports, which account for 71% of
total non-traffic emissions. The major NMHC source is that labeled "miscellaneous"
and includes solvent evaporation, structural fires, and gasoline marketing. This
category accounts for 71% of the non-traffic NMHC emissions.
Comparing non-traffic to traffic emissions, traffic constitutes 97% and 68% of
total CO and NMHC emissions respectively.
20
-------
Table 7. BASE YEAR (1975) NON-TRAFFIC EMISSIONS
AND TOTAL EMISSION SUMMARY.
(tons/day)
Emission Source
Point Sources
Area Sources
Residential
Commercial/Institutional
Industrial
Miscellaneous
Gas Handling
Solvent Evaporation
Structural Fires
Airports
Railroads
Total Non- Traffic
Total Traffic
Grand Total
Emissions
CO
0.7
0.6
1.1
4.8
0.0
0.0
1.0
27.1
3.0
38.3
1086.7
1125.0
MNHC
13.5
0.3
l.ft
19.2
30.5
0.0
2.9
2.2
70.0
151.7
221.7
21
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V. PROPOSED EMISSION CONTROL STRATEGIES
Eleven emission control strategies were recommended by the AQMA Technical
Operations Committee for evaluation by the AQMATF.
1) Traffic System Improvements Including Highway Construction
2) Improved Mass Transit Including Transit Incentives
3) Regional Development Planning
4) Inspection/Maintenance
5) Periodic Maintenance
6) Dealer Emissions Control Maintenance Guarantee
7) Clean Air Rebate
8) Carpooling
9) Vapor Recovery
10) Bicycle Systems
11) Work and Driving Schedule Shifts
Control strategies * and 8, namely the inspection/maintenance program and
voluntary carpooling, are now in operation. Traffic system improvements, improved
mass transit and regional development are ongoing activities and are implicit in the
transportation system and land use plan presently adopted by the MAG Regional
Council.
22
-------
DESCRIPTION OF PROPOSED CONTROL STRATEGIES
A description of each control strategy is presented below:
Traffic System Improvements Including Highway Contructipn
By upgrading the metropolitan area's traffic signal systems to operate under
direct computer control, there would be an increase in the overall traffic speed, which
would lead to a reduction in emissions of both CO and NMHC. Other improvements
include freeway construction, major street construction, widening, freeway ramp
metering, and the removal of on-street parking. It is the responsibility of the city,
county and state governments, with the coordination provided by MAG, to implement
these improvement measures.
Figure 8 presents the Transportation System Plan for Maricopa County that has
been accepted by the Regional Council of the Maricopa Association of Governments as
the basis for the continuing process of transportation system planning and implementa-
tion. Freeways in the present plan to be completed by 1985 are represented by double
lines, while the remaining freeway system, depicted by dashed lines, is scheduled for
completion in 1995. For comparison, the existing transportation network is presented in
Figure 9. In 1975 there were 177 lane miles, by 1985 there will be 432 lane miles and in
1995, 825 lane miles. Under the current MAG plan, "freeway" includes parkways and
expressways.
Improved Mass Transit Including Transit Incentives
The City of Phoenix operates the regional bus system in the Valley, which
currently includes 182 buses in service with expansion to 400 buses scheduled by 1982.
With this expansion, the service area and frequency of service will be increased and
additional express bus service will be provided. Dial-a-ride service is already being
provided in Glendale and there are plans being prepared in Scottsdale, Paradise Valley
and Laveen for expansion of service to 90 square miles of the region.
Along with service expansion, incentives to ride transit are being provided. These
include better passenger information systems such as ticket sales at many of the banks,
and the construction of a bus terminal facility in downtown Phoenix. Other incentives,
23
-------
ro
SCALE OF MILES
012345
Major street
Committed
Freeway/Parkway
Expressway
MARICOPA
COUNTY
TRANSPORTATION
SYSTEM PLAN
PRIMARY PLANNING AREA
Figure 8. Transportation system plan for Maricopa County.
-------
I >
SCALE OF MILES
01 2345
M ARICOPA i
COUNTY Lj
1975 PHOENIX REGION
FREEWAY AND
ARTERIAL SYSTEM
PHOENIX
PRIMARY PLANNING AREA
Figure 9. Existing transportation network.
-------
such as downtown shuttle services and reduced fares have been and will continue to be
considered.
The MAG 1985 and 1995 traffic assignments used to develop the mobile source
emissions inventories reflect increases in transit patronage from .6% in 1975 to 1.6% in
1985 and 1995,-based on the MAG 1976-1981 Transit Development Program (1985) and
long-range transit plan systems (1995). The bases for these transit projections are
presented in Five YearJTransit Development Program Fiscal Years 1977-1981, (MAG,
1976).
Regional Development Planning
The Maricopa Association of Governments (MAG) is responsible for conducting
regional development planning in Maricopa County. The Composite Land Use Plan for
Maricopa County (MAG, 1976) was used as the basis for the Air Quality Maintenance
Analysis. This plan assumes a gradual increase in gross residential density from 3,500
persons per square mile in 1975 to 4,800 persons per square mile in 2000. This increase
would occur as a result of infilling of vacant parcels and some redevelopment of older
marginal or transitional neighborhoods. There would also be some increase in the
percentage of medium density residential units (6-14 dwellings per acre) and a
corresponding decrease in very low density units (less than 2 dwellings per acre). This
concept also includes the Central Phoenix Plan which envisions substantial commercial
development in the Central Avenue Corridor. Additional concentrations of commer-
cial/service employment are located in the central core areas of Glendale, Mesa,
Scottsdale and Tempe. Approximately 70 percent of all employment opportunities
would be located in the "existing urban districts" (See Figure 10).
The general pattern of development is illustrated in Figure II. Although much of
the future development would occur in and immediately adjacent to the existing urban
development, by 2000 the urbanized area would extend outward into new areas, most
notably, northward to the CAP Canal, into the Northeast Scottsdale area, and along the
1-10 Corridor - which would link Phoenix to the Tolleson, Goodyear, and Avondale areas.
The outward spread of the urban area would be somewhat contained so that
approximately 70 percent of existing agricultural lands would be preserved.
26
-------
Figure 10. Existing urban districts.
-------
CO
00
Figure 11. Generalized urban boundaries projected to be developed by the year 2000.
-------
Inspection/Maintenance
Under existing Arizona State Revised Statutes, beginning January I, 1977 all
vehicles under 1* years of age that are registered in Maricopa and Pima Counties for
highway use are to be inspected at least once a year. For this purpose, a fleet of
inspection stations including State operated ones would be available. The vehicles
receiving the inspection are required to pass or be issued a waiver after performing the
prescribed maintenance. This program is aimed at proper maintenance of the engine as
a system, which would lead to a reduction of both CO and NMHC emissions.
Periodic Maintenance
This type of program is similar to the inspection/maintenance program except
that instead of inspections, all vehicles undergo mandatory periodic maintenance, which
results in maximum reductions since every car engine is adjusted or tuned. Periodic
maintenance occurs at the same time as annual vehicle registration and relies upon the
automotive repair industry to perform the necessary engine check and required
maintenance. Repair facilities are required to be licensed and mechanics performing
the maintenance must be certified.
Dealer Emissions Control Maintenance Guarantee
This control strategy requires a maintenance guarantee by the dealer to the
vehicle buyer to perform all and necessary adjustments, maintenance and repair to meet
required engine emission standards for a specified period of time, say five years. Cost
of such a guarantee could probably be absorbed by the dealer and/or manufacturer or
could be a direct cost to the purchaser.
Currently some automobile companies have programs related to this concept for
new cars only. One warrantees its engine for 5 years or 75,000 miles, whichever comes
first. Another warrantees its ^-cylinder aluminum engine for 5 years or 60,000 miles,
whichever comes first. Both warrantees are honored only if the vehicle owner
accomplishes the periodic maintenance specified.
Clean Air Rebate
This control strategy has two possible concepts. The first involves levying an
emissions tax on all vehicles based on emissions performance. The second concept
29
-------
involves levying a tax based on the pollution contribution of a vehicle. This pollution
contribution can be determined from the annual miles traveled by a particular vehicle
and the emissions (in terms of grams per mile) from that vehicle. As an incentive to
reducing emissions, there would be a rebate on cars that contribute less to air pollution
than the average vehicle.
Car pooling
Increasing the number of riders per automobile can effect a major reduction in
vehicles on the road. Average automobile occupancy in Phoenix is 1.35 persons per car.
Average occupancy for work trips is presently 1.13 persons per car. Since most cars are
capable of carrying four persons, there is considerable room for reducing automobile use
and emissions through carpooling. Two things are essential to the success of a program
to increase carpooling: convenience and necessity. The principal obstacle to carpooling
is that carpools are highly restrictive in terms of the service offered. Carpoolers must
have trip origins and destinations that are close to one another, must desire to travel at
the same times of the day, and, to minimize the problems of locating carpool partners,
must make trips that are repetitive from day to day. As a result, the greatest potential
for increased carpool use is in connection with peak-period work trips, which are
responsible for about 25% of urban area automobile emissions.
Vapor Recovery
Without proper vapor recovery devices, NMHC emissions result during the transfer
of gasoline from one receptacle to another. In the process of filling a service station's
main supply tanks, vapor that exists above the gasoline in the tanks can be vented back
into the tanker, displacing the gasoline being transferred to the tanks. This means of
preventing NMHC emissions to the atmosphere is known as Phase I Vapor Recovery.
The control of vapor loss when filling the tank of a vehicle at a gasoline station is
known as Phase II Vapor Recovery. This second phase can be accomplished by venting
the vapor from the vehicle's tank, by a double hose, to the service station's main tanks.
Bicycle Systems
Increases in the use of bicycles in urban areas could diminish the total vehicle
miles traveled by vehicles, which in turn would lead to a reduction in emissions.
30
-------
There are approximately 50 miles of bikeways in operation in the Phoenix metro-
politan area including striped lanes on existing streets and separate exclusive lanes.
Bike lanes are required to be built adjacent to all new major streets in the City of
Tempe. The City of Scottsdale has an adopted bicycle plan, while the City of Phoenix is
in the process of developing policies associated with a city-wide network of bicycle
paths. Short-term plans for the region presently provide for the addition of 90 miles of
bikeways to the existing system.
Work and Driving Schedule Shifts
This control strategy would not result in any reduction in vehicle miles traveled.
However, by staggering the starting and quitting hours, work-related trips would be
distributed over a longer time period thereby alleviating peak-hour congestion and
leading to lesser CO and NMHC emissions. The spreading of emissions over a longer
period also has the effect of decreasing peak hour CO levels.
EFFECTIVENESS OF PROPOSED CONTROL STRATEGIES- DETERMINED BY THE
TECHNICAL OPERATIONS COMMITTEE
The effectiveness of these control strategies in reducing CO and NMHC emissions
was determined by the AQMA Technical Operations Committee. This effectiveness
data was then used for calculating emissions projections as discussed in the next
chapter.
Implicit in the traffic data base from which emission projections were developed
was the existence of the first three control strategies, viz., traffic system improve-
ments, improved mass transit and regional development planning. No specific emission
reductions were assigned to these strategies.
According to the latest results obtained by the Bureau of Vehicular Emissions, the
inspection/ maintenance program would lead to 22% and 37% reduction in CO and
NMHC emissions, respectively, from all light duty vehicles, including motorcycles. This
reduction corresponded to a 16.8% failure rate as observed during the first three months
of the Phoenix I/M program. Such a program would also result in 11% and 7% reduction
in CO and NMHC emissions, respectively, from all heavy duty vehicles. Percentage
emission reductions for heavy duty vehicles were obtained from the Transportation
Control Strategies (ASDH, 1973). These reductions could be increased by adjusting
emission standards.
31
-------
Periodic maintenance would have the effect of reducing CO and NMHC emissions
from all light and heavy duty vehicles by 35% and 34% respectively. This data was
derived from a study performed by Clean Air Research Company for the California Air
Resources Board. (Gockel, 1973).
Both the dealer emissions guarantee and clean air rebate are incentive programs
designed to support the inspection/maintenance or periodic maintenance programs and
would, by themselves, be ineffective in reducing vehicle emissions.
Carpooling programs aimed at reducing work trips could reasonably be expected to
increase car occupancy from 1.35 in 1976 to 1.* in 1985 and 1.5 in 1995. This would
lead to a decrease of 5% in both CO and NMHC emissions from all light duty vehicles in
1985 and a decrease of 12% and 11% for CO and NMHC respectively, in 1995. These
figures are based on results of the MAG Sketch Planning Models.
It is anticipated that if vapor recovery were implemented, Phase I would be in full
operation by 1985 and both Phase I and II would be in effect by 1995. These dates are
fairly conservative as the technology for vapor recovery has already been developed and
actual implementation could be achieved more rapidly if necessary. There would be a
36% reduction in NMHC emissions from gasoline marketing sources in Phoenix in 1985
from Phase I and an 81% reduction in NMHC emissions in 1995 with both Phase I and II
in operation. (Witherspoon, 1976).
Bicycle systems are not expected to have any effect on emissions by 1985 but
would reduce both CO and NMHC emissions in 1995 by 0.6%. This effectiveness data is
inferred from the San Diego Air Quality Planning Report (Planning Environment
International, 1976).
The implementation of work and driving shifts would flatten out the traffic during
the morning and afternoon rush hours. Effects of this control strategy are presented in
Table 8.
32
-------
Table 8. CHANGES IN PERCENT AVERAGE DAILY TRAFFIC (% ADT)
WITH THE IMPLEMENTATION OF WORK AND DRIVING SHIFTS.
Hour of Day
Affected
6
7
8
15
16
17
Freeway % ADT
Base Case
4.5
9.4
7.7
7.1
9.4
8.5
Working and
Driving Shifts
7.2
7.2
7.2
8.4
8.3
8.3
Arterial % ADT
Base Case
3.1
8.1
6.5
7.5
8.8
8.2
Working and
Driving Shifts
5.9
5.9
5.9
8.2
8.2
8.1
33
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VI. EMISSIONS INVENTORY PROJECTION
PROJECTION METHODOLOGY
Emission projections were made for 1980, 1985, 1990, 1995, and 2000. The effects
of selected CO and NMHC emission control strategies on areawide emissions were also
determined. These emission projections were based on a population forecast for 1995 of
2.2 million (1.7 million in 1985), which is the mean value of the latest Arizona
Department of Economic Security's low and high projections for Maricopa County (DES,
1976), adjusted for the smaller study area.
Vehicle miles traveled (VMT) for 1985 and 1995 were obtained from traffic link
data provided by MAG. The 1985 traffic data was derived from the Approved Regional
Transportation Plan (MAG, 1976) including existing and committed freeways for 1985
and based on a 1.7 million population. The 1995 traffic network was also derived from
the regional plan assuming a 2.2 million population and a planned freeway configuration
for 1995. Both traffic systems include changes which would be incorporated with the
implementation of traffic system improvements, improved mass transit, and regional
development training by the given study year. VMT for 1980, 1990, and 2000 were
derived using linear interpolation or extrapolation for each vehicle class. The VMT data
are presented in Figure 12. Freeway lane miles are 177 for 1975, 432 for 1985 and 825
for 1995. Emissions were then derived from these years using emission factors
appropriate to those years, VMT as described above, and an average speed for each
vehicle class and roadway type. This average speed was based on linear interpolation or
extrapolation of speeds in 1975, 1985, and 1995.
Non-traffic emissions for 1995 were obtained using projections in Emission In-
ventory Report for the Phoenix^ Study Area, (PES, 1976) for a population of 1.9' million.
These were revised to reflect a 2.2 million population level by taking into account
changes In growth rate due to this higher population estimate. Projections for 1980,
1985, 1990, and 2000 were made by assigning appropriate growth rates and emission
factor adjustments to each source and applying these to the base year inventory.
Growth rates were generally derived through linear interpolation or extrapolation based
on 1975 and 1995 land use areas, population, etc. Emission factor adjustments were
based on forecast schedules of emission control measures (e.g., pilot light phaseout and
energy conservation).
-------
1975
1980
1985 1990
Years
1995
2000
Figure 12. Projected vehicle miles traveled per day by facility type.
35
-------
Details of emission projections are presented in Appendices B and D.
PRO3ECTED EMISSIONS
Projected traffic emissions are presented in Table 9. Because traffic system
improvement, improved mass transit, and regional development planning were implicit
in the traffic network data provided by MAG, a scenario without these controls was not
analyzed. Since these three control strategies constitute the basic scenario, projections
incorporating them will be referred to as the "base case."
The general base case trend is illustrated by Figure 13. Comparison with Figure
12 presented earlier reveals that, while VMT increases, traffic emissions decrease
through 1990 due primarily to increasingly strict emission control regulations on light
duty gasoline powered vehicles. This vehicle class continues to be the primary NMHC
contributor, but by 1995 the major contribution to primary traffic CO emissions has
become heavy duty gasoline trucks, since projected emission control regulations on this
vehicle class are not as strict as on light-duty vehicles. The contribution of heavy duty
gasoline trucks is expected to increase to 54% of primary traffic CO emissions by 1995.
Table 10 presents projected non-traffic emissions. The trend is illustrated graph-
ically in Figure 14. CO emissions are expected to increase, primarily due to increased
airport activity. Airports will continue to be the dominant non-traffic source, contri-
buting 65% in 1995. NMHC emissions are expected to decrease through 1995 in spite of
increased gasoline marketing primarily because of the increased use of non-polluting
solvents. Miscellaneous emissions, primarily solvent evaporation and gasoline market-
ing, will continue to be the dominant non-traffic NMHC source in 1995, contributing
63%.
Despite major emission reductions, traffic will continue to be the major contri-
butor to the total CO emission picture, accounting for 85% in 1995. Traffic emissions
will only be 46% of the total NMHC emissions in 1995, however.
Without implementation of any of the control strategies except the first three,
described in Chapter V, total emissions will have been reduced by 67% and 47% for CO
and NMHC respectively by 1995. The total emission trend for both pollutants is
illustrated in Figure 15.
36
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Table 9. PROJECTED TRAFFIC EMISSIONS- BASE CASE.*
(tons/day)
Vehicle Type
Primary Traffic
Light Duty Autos
Light Duty Trucks
Heavy Duty Gas Trucks
Light Duty Diesel Trucks
Heavy Duty Diesel Trucks
Motorcycles
Subtotal
Secondary Traffic
Total Traffic
1980
CO
293.6
109.1
132.1
<0.1
4.6
4.0
543.4
91.7
635.1
NMHC
59.4
22.0
15.2
<0.1
0.9
0.9
98.4
14.9
114.3
1985
CO
116.3
67.1
123.7
<0.1
5.3
4.2
316.6
47.6
364.2
NMHC
32.8
15.1
11.4
<0.1
1.1
0.9
61.2
9.2
70.4
1990
CO
59.8
50.3
135.2
<0.1
6.2
1.4
252.9
29.6
282.5
NMHC
21.1
11.7
10.4
<0.1
1.2
0.4
44.8
6.0
50.8
1995
CO
65.4
57.2
155.4
<0.1
7.2
1.6
286.9
31.7
318.6
NMHC
21.9
11.1
12.7
<0.1
1.5
0.5
47.7
6.5
54.1
2000
CO
74.4
65.6
177.9
<0.1
8.1
1.8
327.8
38.9
366.7
NMHC
24.6
12.7
14.5
<0.1
1.7
0.5
54.0
7.0
61.0
Actually incorporates the following controls: (1) traffic system improvements, (2) improved mass
transit, and (3) regional development planning.
-------
1
"X
tn
I
1975
1980
1985 1990
YEARS
1995
2000
Figure 13. Traffic emissions trend through 2000.
-------
Table 10. PROJECTED NON-TRAFFIC EMISSIONS- BASE CASE.
(tons/day)
Emission Source
Point Sources
Area Sources
Residential
Commercial/Institutional
Industrial
Miscellaneous
Gas Handling
Solvent Evaporation
Structural Fires
Airports
Railroads
Total Non-Traffic
1980
CO
0.7
0.8
1.3
5.8
0.0
0.0
1.2
27.9
3.2
40.9
NMHC
13.5
--
0.3
1.7
22.8
27.3
0.0
3.0
2.3
70.9
1985
CO
0.7
0.9
1.5
5.8
0.0
0.0
1,4
28.7
3.4
42.3
NMHC
13.5
-_
0.4
1.7
26.5
21.1
0.0
3.1
2.4
68.7
1990
CO
0.6
1.0
1.6
7.8
0.0
0.0
1.6
32.3
3.8
48.7
NMHC
13.5
0.4
2.3
30.4
14.5
0.0
3.2
2.7
67.0
1995
CO
0.6
1.1
1.7
10.1
0.0
0.0
1.8
36.1
4.2
55.6
NMHC
13.4
0.4
2.9
34.3
5.5
0.0
3.4
3.0
62.9
2000
CO
0.6
1.2
1.9
13.5
0.0
0.0
2.0
39.7
4.6
63.5
NMHC
13.4
0.5
3.9
38.2
6.1
0.0
3.5
3.3
68.9
u>
vO
-------
10
1975
1980
1985 1990
YEARS
1995
2000
Figure 1*. Non-traffic emission trend through 2000.
-------
1975
1980
1985 1990
YEARS
1995
2000
Figure 15. Total emission trend through 2000 for the base case incorporating
the following controls: (1) traffic system improvements, (2) improved
mass transit, and (3) regional development planning.
-------
EFFECT OF IMPLEMENTATION OF ALTERNATE CONTROL STRATEGIES ON
EMISSIONS
Tables 11 and 12 present the effect of control strategies on total study area
emissions (traffic and non-traffic). All control strategies affect traffic sources only,
with the exception of vapor recovery. The control strategy involving work and driving
schedule shifts was projected for 1985 and 1995 because traffic link data for those years
was available. Appendix E presents detailed breakdowns of emissions under the various
control strategies.
The most effective CO control strategy is periodic maintenance. With this
strategy a reduction of 30% in CO emissions, compared to that for the base case, could
be achieved by 1995. Inspection/maintenance, the second most effective strategy,
would achieve a 14% reduction in total emissions assuming a 16.8% failure rate.
The most effective NMHC control strategy by 1995 is vapor recovery (Phases I
and H). An emission reduction of 24% over no controls is projected. An NMHC emission
reduction of 16% is projected for periodic maintenance, the second most effective
strategy.
Dealer emission control maintenance guarantees and clean air rebate control
strategies would be ineffective by themselves. They would, however, be incentive
measures supporting the inspection/maintenance or periodic maintenance control
strategies.
As mentioned in Chapter V, inspection/maintenance and carpooling are ongoing
programs in the Phoenix area. Included in Tables 11 and 12 is the combined effect of
these strategies.
-------
Table 11. PROJECTED TOTAL CO EMISSIONS UNDER ALTERNATE CONTROL STRATEGIES.
(tons/day)
Control Strategy
Base Case*
Inspection/Maintenance
Periodic Maintenance
Dealer Emission Guarantee
Clean Air Rebate
Car pool ing
Vapor Recovery
Bicycle Systems
Work and Driving
Schedule Shifts
Inspect i on/Mai ntenance
and Car pool ing
1980
Total
676.0
551.3
453.7
676.0
676.0
661.1
676.0
676.0
.-
539.7
Reduction
%
12*. 7
222.3
0.0
0.0
14.9
0.0
0.0
--
136.3
..
18.4
32.9
0.0
0.0
2.2
0.0
0.0
--
20.2
1985
Total
406.5
340.5
279.0
406.5
406.5
394.8
406.5
406.5
405.5
331.4
1
Reduction
%
65.9
127.5
0.0
0.0
11.7
0.0
0.0
l.l
75.1
_.
16.2
31.4
0.0
0.0
2.9
0.0
0.0
0.3
18.5
1990
Total
331.2
284.3
232.3
331.2
331.2
318.3
331.2
330.4
--
275.1
Reduction
%
46.9
98.9
0.0
0.0
12.9
0.0
0.8
--
56.1
__
14.2
29.9
0.0
0.0
3.9
0.0
0.2
16.9
1995
Total
374.2
322.0
262.7
374.2
374.2
355.6
374.2
373.2
372.8
307.9
Reduction
%
52.2
111.5
0.0
0.0
18.6
0.0
1.0
1.4
66.3
_ğ
13.9
29.8
0.0
0.0
5.0
0.0
0.3
0.4
17.7
2000
Total
430.5
369.6
302.9
43.0.5
430.5
400.7
430.5
429.2
--
3*2.7
Reduction
%
60.9
127.6
0.0
0.0
29.8
0.0
1.3
--
87.8
.
14.1
29.6
0.0
0.0
6.9
0.0
0.3
-
20.4
From base case
Incorporates the following controls! (1) traffic system improvements, (2) improved mass transit, and
(3) regional development planning.
-------
Table 12. PROJECTED TOTAL NMHC EMISSIONS UNDER ALTERNATE CONTROL STRATEGIES.
(tons/day)
Control Strategy
Base Case2
Inspection/Maintenance
Periodic Maintenance
Dealer Emission Guarantee
Clean Air Rebate
Carpooling
Vapor Recovery
Bicycle Systems
Work and Driving
Schedule Shifts
Inspect! on/ Maintenance
and Carpooling
1980
Total
185.2
1*7.1
1*5.6
185.2
185.2
181.3
181.1
185.2
145.3
Reduction
%
__
38.1
39.6
0.0
0.0
3.9
*.l
0.0
--
39.9
..
20.6
21.*
0.0
0.0
2.1
2.2
0.0
--
21.5
1985
Total
139.1
116.9
115.2
139.1
139.1
136.3
129.5
139.1
139.0
115.1
Reduction
%
--
22.2
23.9
0.0
0.0
2.8
9.6
0.0
0.1
2*.0
--
16.0
17.2
0.0
0.0
2.0
6.9
0.0
0.1
17.3
1990
Total
117.8
102.0
100.6
117.8
117.8
11*.7
100.0
117.6
--
100.1
Reduction
%
--
15.8
17.2
0.0
0.0
3.1
17.8
0.2
--
17.7
--
13.*
10.6
0.0
0.0
2.6
15.1
0.2
--
15.0
Total
117.0
101.3
98.6
117.0
117.0
112.8
88.8
116.7
117.0
98.6
1995
Reduction
%
--
15.7
18.*
0.0
0.0
*.2
28.2
0.3
0.0
18.*
--
13.*
15.7
0.0
0.0
3.6
2*.l
0.3
0.0
15.7
Total
129.9
112.2
109.1
129.9
129.9
123.7
98.9
129.7
--
108.3
2000
Reduction
%
--
17.7
20.8
0.0
0.0
6.2
3i.O
0.2
21.6
-
13.6
16.0
0.0
0.0
*.&
23.9
0.2
"
16.6
From base case.
Incorporates the following controls: (1) traffic system improvements, (2) improved mass transit, and
(3) regional development planning.
-------
VII. MODELING OF CO AIR QUALITY
The APRAC-H model was used in the simulation of severe CO air quality in the
Phoenix study area. A description of the APRAC-II model appears in Appendix F.
CASE SELECTION
During the base year, 1975, the highest 8-hour average CO reading was 34 mg/m
(30 ppm), which was recorded at monitoring Site 3 on 13 November 1975. The locations
of Site 3 and other air quality/meteorological monitoring stations in Phoenix were
presented in Figure 3. The second highest reading was 30 mg/m (26 ppm), observed on
if November, 1975, also at Site 3.
In determining these highest and second highest 8-hour values, the Environmental
Protection Agency's recommendation in Guidelines for the Interpretation of Air Quality
Standards (U.S. EPA, 1974) was followed.
Communications with officials of the Arizona Department of Health Services
(ADHS) indicated that there was extensive controlled forest burning during the 13-14
November period, which was significant in terms of poor air quality but not a repre-
sentative period to simulate automobile generated air pollution. Consequently, data for
13 November was discarded.
Meteorological conditions during 4-5 November, 1975, the day with the second
highest 8-hour average, were very conducive to high carbon monoxide concentrations.
Consequently, the period beginning at 1900 on 4 November during which the 8-hour
carbon monoxide average was 30 mg/m (26 ppm) was singled out for modeling.
APRAC-II INPUTS
Simulation of carbon monoxide air quality by means of the APRAC-II model
requires two primary types of inputs - emissions and meteorology.
-------
Emissions
The APRAC-H model requires emissions from each link in a roadway network for
each hour of a day. These emissions were computed by means of AVSUP5, as discussed
in Chapter IV. In addition to emissions from primary traffic for each link, the model
also needs emissions from secondary traffic and non-automobile sources to be supplied
in grid form. This emissions data, discussed in Chapter IV, was distributed into 2200
grids, one square mile each, defined by locating the point x = 0 at 2.5 miles west of
3ackrabbit Trail and the point y = ĞK> at Ğf.5 miles north of Pinnacle Peak Road. The
emissions grid map is presented in Figure 16.
Meteorology
On *-5 November 1975, the meteorology in Phoenix was dominated by a large high
pressure system centered around northeastern Utah (Figure 17). The 500-millibar
synoptic charts for 4 November showed descending air over Arizona. Stagnation
conditions were reported throughout Phoenix during the 8-hour period beginning at 1900
on * November. Winds, when detectable, were light and generally from the north.
Wind data at receptor points used in the calculation of carbon monoxide
concentration was determined from wind records at six wind stations. Actual data used
is presented in Table 13. The minimum wind speed acceptable to APRAC-II is 1 m/s.
This accounts for the many 1 m/s speeds in Table 13, which were actually calm.
To determine atmospheric stability, weather observations at Sky Harbor Airport
were used. The wind data reported at Sky Harbor was not an hourly averaged reading,
but rather, represented an instantaneous observation on the hour. Since this
information was not representative of transport conditions during a one-hour period,
wind information at Sky Harbor was not used to determine the transport wind at
receptors. This wind speed data was used in conjunction with other parameters in the
determination of atmospheric stability, however. This data is presented in Table 1*.
Since there was no mixing height information available for this period, a mixing
correction factor of 15 m was used because this factor resulted in excellent correlation
between observed and predicted values and minimized the difference between observed
and predicted concentrations. In essence, one can say that the mixing height was
adjusted so as to provide a best-fit to the data.
-------
IR QUALITY
MAINTENANCE AREA
SCALE ( = MILES
01 2345
AEROVIRONMENT INC.
Figure 16. Emissions grid map.
-------
Figure 17. Surface weather map at 7:00 a.m. EST on 4 November 1975.
-------
Table 13. WIND DATA USED FOR THE APRAC-H SIMULATIONS.
Date
11/4
11/5
Site
Hour
19
20
21
22
23
00
01
02
1
WD
360
360
360
360
360
360
10
35
WS*
1.3
1.3
1.3
1.0
1.3
1.0
1.3
1.8
2
WD
360
310
360
310
310
310
310
30
WS
1.0
1.0
1.0
1.0
1.3
1.0
1.0
1.3
4
WD
360
360
10
20
15
10
30
30
WS
1.8
2.2
1.8
2.2
1.3
1.8
1.3
1.0
6
WD
30
360
5
355
315
285
320
320
WS
2.2
2.2
2.7
2.7
1.8
1.3
1.0
1.0
8
WD
25
25
340
360
10
340
340
340
WS
1.3
1.0
1.0
1.3
1.0
1.0
1.0
1.0
9
WD
45
45
45
45
35
30
20
20
WS
1.8
2.2
2.7
3.1
3.1
3.6
2.2
3.1
* Meters/sec
-------
Table 1*. METEOROLOGICAL DATA (AT SKY HARBOR AIRPORT) USED
TO CALCULATE ATMOSPHERIC STABILITY.
Date
11/4
11/5
Hour
19
20
21
22
23
00
01
02
Wind Speed
(Knots)
6.0
5.0
*.o
3.0
5.0
3.0
6.0
6.0
Temperature
TK)
300
297
296
295
29*
293
293
291
Cloud Cover
(tenths)
0
0
0
0
0
0
0
0
50
-------
APRAC-II VERIFICATION
The 8-hour CO air quality beginning at 1900 on k November 1975 was simulated to
verify the predictive accuracy of the APRAC-II Model. Concentrations were calculated
at all locations which monitored carbon monoxide. Both predicted and observed values
are presented in Table 15. Figure 18 shows a linear regression plot of observed versus
predicted concentrations. The correlation coefficient was 0.97. The intercept was -0.6
while the slope was 2.56.
Although there were only six data points, (data was not available at one of the
seven stations measuring CO), the correlation coefficient was significant. Such a good
fit indicated that the model was able to predict reasonably well the spatial variability
of carbon monoxide during the selected episodic period in Phoenix.
To derive absolute values from predictions, a correction factor of 2.47 was used.
This correction factor was calculated as follows:
ZXY
Correction factor = =- ,
2 X*
where X's are predicted concentrations and Y's are observed concentrations,
Adjusted predictions and observed concentrations are presented in Table 16 and
1 2
Figure 19. The standard error of estimate was 2.0 ppm . This value is less than 10%
of the highest predicted concentration of 23.3 ppm and should be considered acceptable.
Overall, the model performed quite well in simulating "hot spots" and high carbon
monoxide concentrations observed at the six monitoring sites during an episodic period.
Thus, in simulating the air quality under identical meteorological conditions for the
future, the APRAC model can be used with reasonable confidence and the predictions
should be considered good to within +2 ppm (+ 2 mg/m ).
1 Standard error of estimate = V z /N where Y& is the adjusted value and
Y the corresponding observed value.
2 Concentrations are presented in ppm for CO. To convert from ppm to mg/m ,
multiply the value by 1.15.
51
-------
Table 15. A COMPARISON OF PREDICTED AND OBSERVED 8-HOUR
AVERAGE CO CONCENTRATIONS (ppm).
Site
1
3
4
6
g
9
Observed Value
10.8
26.1
2.1
2.0
4.8
1.3
Predicted Value
6.1
9.5
.7
1.2
2.0
.5
52
-------
i
a
1
§
<3
y = -0.6 + 2.56 x
ta
JU
_n
Predicted Concentration (ppm)
Figure 18. A linear regression plot of observed versus predicted concentrations.
53
-------
Table 16. A COMPARISON OF OBSERVED VALUES AND AD3USTED PRE-
DICTIONS OF 8-HOUR CO CONCENTRATIONS (ppm).
Site
1
3
4
6
8
9
Observed Value
10.8
26.1
2.1
2.0
4.8
1.3
Adjusted Prediction
14.9
23.3
1.7
3.0
4.9
1.2
-------
30
25
i
1
u
a
o
20
15
10
10 15 20 25
Adjusted Predictions (ppm)
Figure 19. A scatter diagram showing observed data versus adjusted predictions.
55
-------
CO AIR QUALITY IN 1975, 1985 AND 1995 WITHOUT ADDITIONAL CONTROL
STRATEGIES1
Figure 20 presents predicted concentration isopleths of the severe-case 8-hour CO
concentrations in Phoenix in 1975. Highest values were predicted a couple of miles
south of the Phoenix commercial district (Central and Van Buren). The slight southward
displacement of the CO peak from the traffic hot spots is a direct consequence of the
light northerly winds that were observed during this period. Exceedances of the 8-hour
standard of 9 ppm were predicted to occur in an extensive area bounded to the east by
56th Street, to the west by 51st Avenue, to the north by Indian School Road, and to the
south by the Gila River Indian Reservation. The highest peak was 32.3 ppm,
approximately four times the 8-hour CO standard.
Isopleths of predicted 8-hour average CO concentrations in 1985 and 1995 without
any additional control strategies (base case) are shown in Figure 21 and 22 respectively.
Locations of CO hot spots were identical to those predicted for the 1975 case, which
was to be expected since the same meteorology was assumed. Peak readings in 1985
and 1995 were predicted to be 11.7 ppm and 8.6 ppm respectively. Exceedances of the
8-hour CO standard were predicted for the 1985 case but not for the 1995 case.
The gradual improvement in the 8-hour CO air quality from 1975 to 1985 is attri-
buted to a gradual reduction in CO emissions for the same time period. This reduction
is largely related to the assumption that newer cars emit less pollutants than older cars,
an assumption implicit in emission factors in Supplement 5 of AP-^2. Therefore, as
time goes by, even though there would be more cars on the road, the total emissions
generated by these newer cars would be less than emissions from older cars that were
being replaced.
This improvement is expected to continue until 1990, by which time all cars on the
road will be equipped with similar emission control devices. Beyond 1990, emissions
generated by motor vehicles will increase at a rate proportional to population growth,
unless further controls are introduced in the future. This trend was illustrated in Figure
13. By 1995, CO emissions in the area would result in a peak CO concentration of 8.6
ppm as discussed.
It was assumed that traffic system improvements, improved mass transit and
regional development planning are ongoing activities. Without additional control
strategies here refers to the base case when only these three control strategies
are implemented.
56
-------
Figure 20. Isopleths of predicted 8-hour CO concentrations in ppm
for the 1975 case. The locations of the monitoring sites
are shown.
-------
00
Figure 21. Isopleths of predicted 8-hour average CO concentrations in ppm for 1985 without 8 additional
control strategies (base case). The locations of the monitoring sites are shown.
-------
\D
Figure 22. Isopleths of predicted 8-hour average CO concentrations in ppm for 1995 without 8 additional
control strategies (base case). The locations of the monitoring sites are shown.
-------
Concentrations were also predicted at locations where CO measurements were
taken in 1975. They are given in Table 17. Highest concentrations were predicted at
Stations 1, 2 and 3 in downtown Phoenix. Station 9, in Mesa, was predicted to have the
lowest concentration amongst the seven monitoring sites. Exceedances were predicted
at three stations in 1975 and at none in 1985 or 1995.
CO AIR QUALITY IN 1985 AND 1995 WITH THE IMPLEMENTATION OF INSPECTION/
MAINTENANCE AND CARPOOLING
The inspection/maintenance program and voluntary carpooling are strategies that
are currently being implemented in Phoenix. It is essential to determine whether their
existence alone is all that is required to maintain the 8-hour CO standard. With this in
mind, the APRAC-II model was applied to simulate severe case CO air quality in 1985
and 1995 in Phoenix when these two strategies are allowed to continue indefinitely.
Added to these strategies are traffic system improvements, improved mass transit and
regional development planning, all of which are part of an on-going planning process.
The only change in model inputs from the model runs presented in the last chapter
was automobile emissions. A 26% reduction in CO emissions from light-duty vehicles in
1985 was taken into account. (With inspection/maintenance alone, there would be a
reduction of 22% in CO emissions from light-duty vehicles. With carpooling alone, the
reduction would be 5%. The effect of implementing carpooling on top of inspection/
maintenance was a reduction of 26% in CO emissions.) At the same time, an 11%
reduction in CO emissions from heavy-duty vehicles, resulting from the inspection/main-
tenance program, was also considered. Emissions reductions attributable to the
inspection/maintenance program was not expected to increase in 1995. However, it was
assumed that increases in carpooling would result in a 12% reduction in CO emissions
from light-duty vehicles by 1995. Thus, in 1995, emissions from light-duty vehicles
would be reduced by 31% while those from heavy-duty vehicles by 11%.
Model results are presented in Figures 23 and 21. Again, because the same severe
meteorological conditions were assumed, the spatial distribution of CO concentrations
remained very similar to that in Figure 20. With the continuation of the
inspection/maintenance and carpooling programs, the highest CO peak in 1985 would
drop from 11.7 ppm to 9.7 ppm. The corresponding drop in 1995 was predicted to be
1.5 ppm, i.e., from 8.6 ppm to 7.1 ppm.
60
-------
Table 17. PREDICTED SEVERE-CASE S-HOUR AVERAGE CO CONCENTRATIONS
(PPM) AT MONITORING SITES IN 1975, 1985 AND 1995 FOR THE BASE
CASE. (NATIONAL STANDARD: 9 PPM).
Monitoring
Site
1
2
3
k
6
8
9
1975
14.9
21.9
23.3
1.7
3.0
4.9
1.2
1985
5.2
8.4
8.5
1.2
1.7
2.2
0.8
1995
4.5
6.5
6.2
1.2
1.5
2.0
0.8
61
-------
N)
Scolttdjlc
X7 Municipal
C'ğ,.porl
Figure 23. Isopleths of predicted 8-hour CO concentrations in ppm for 1985 with the implementation of
inspection/maintenance and carpooling. The locations of the monitoring sites are shown.
-------
UJ
Figure 2k. Isopleths of predicted 8-hour CO concentrations in ppm for 1995 with the implementation of
inspection/maintenance and carpooling. The locations of the monitoring sites are shown.
-------
A comparison of predicted concentration at monitoring sites with and without
these strategies is shown in Table 18. When these two strategies are maintained, there
would not be any violation of the 8-hour standard in 1985 and 1995 at existing
monitoring sites.
CO AIR QUALITY IN 1985 AND 1995 WITH THE IMPLEMENTATION OF OTHER CON-
TROL STRATEGIES
No explicit model runs were performed to assess the effectiveness of other
control strategies. However, CO air quality resulting from the implementation of such
control strategies can be inferred from model results presented in the last section.
A comparison of the ratios of predicted peak CO readings to the corresponding CO
emissions for the 5 scenarios modeled is presented in Table 19. It is evident that for
each year, the ratio is a constant. Variations of this ratio with time are attributed to
changes in the distribution of emissions, primarily from changes in the transportation
network from 1985 to 1995. Thus, knowing the total emissions that would result after
the implementation of a certain control strategy, the peak CO reading for a particular
year can be obtained by multiplying that emissions value by the ratio for the same year.
Emissions in Phoenix in 1985 and 1995 with different control strategies
implemented were discussed in Chapter VI. In addition to traffic system improvements,
improved mass transit and regional development planning, the control strategies that
would result in significant CO emission reductions are inspection/maintenance, periodic
maintenance, and carpooling. Using peak CO reading/CO emissions ratios of 0.029 for
1985 and 0.023 for 1995, peak CO readings that would result from different control
strategies were calculated. Table 20 shows the results.
The effect of a combination of inspection/maintenance and carpooling was
discussed in the last section, but is presented again in Table 20 for comparison. The
implementation of inspection/maintenance or carpooling alone in addition to the three
basic control strategies (traffic system improvements, improved mass transit, and
regional development planning) would not result in the attainment of the 8-hour CO
standard of 9 ppm by 1985. Periodic maintenance alone and periodic maintenance with
carpooling would both result in the attainment of the standard by 1985.
-------
Table IS. A COMPARISON OF SEVERE-CASE 8-HOUR CO READINGS (PPM)
AT MONITORING SITES WITH AND WITHOUT THE IMPLE-
MENTATION OF INSPECTION/MAINTENANCE AND CARPOOL-
ING. (NATIONAL STANDARD: 9PPM).
1
Monitoring
Site
1
2
3
it
6
8
9
1985
Without I/M
& Carpooling
(Base Case)
5.2
8.*
8.5
1.2
1.7
2.2
0.8
With I/M
& Carpooling
H.k
7.0
7.1
1.1
1.5
1.9
0.8
1995
Without I/M
& Carpooling
(Base Case)
4.5
6.5
6.2
1.2
1.5
2.0
0.8
With I/M
& Carpooling
3.7
5.4
5.2
1.1
1.3
1.7
0.8
65
-------
Table 19. THE RATIOS OF PEAK CO READINGS TO CO EMISSIONS
DERIVED FROM THE FIVE APRAC-II RUNS.
Year
1975
1985
1985
1995
1995
i
Controls
None
1,2&3
1,2,3,4*5
1,2,&3
1.2,3,4*5
Peak CO2
Reading
(ppm)
32.5
11.7
9.7
8.6
7.1
Emissions
(tons/day)
1125.0
406.5
331.4
374.2
307.9
Ratio
0.029
0.029
0.029
0.023
0.023
Control 1: Traffic systems improvement
2: Improved mass transit
3: Regional development planning
4: Inspection/maintenance
5: Carpooling
National CO 8-hour standard is 9 ppm.
66
-------
Table 20. PREDICTED PEAK 8-HOUR CO READINGS IN 1985 AND 1995 FOR DIFFERENT
CONTROL STRATEGIES.
Control Strategy
Base Case
Base Case plus Inspection/Maintenance (I/M)
Base Case plus Periodic Maintenance (PM)
Base Case plus Carpooling
Base Case plus PM and Carpooling
Base Case plus I/M and Carpooling
1985
2
Emissions
(tons/day)
406.5
340.5
279.0
394.8
271.4
331.4
Peak CO3
Reading
(ppm)
11.7
9.9
8.1
11.4
7.9
9.7
1995
Emissions
(tons/day)
374.2
322.0
262.7
355.6
250.5
307.9
Peak CO
Reading
(ppm)
8.6
7.4
6.0
8.2
5.8
7.1
1 Base Case includes traffic system improvements, improved mass transit and regional development
planning.
2 Total emissions corresponding to a peak 8-hour CO reading of 9 ppm would be 310.3 tons/day in 1985
and 391.3 tons/day in 1995.
3 National CO 8-hour standard is 9 ppm.
-------
PROJECTED CO AIR QUALITY IN 1980, 1990 AND 2000
Modeling of CO air quality using APRAC-II to obtain the multiplicative factor
(ratio of CO peak reading to CO emissions) for 1980, 1990 and 2000 was not possible
because of lack of detailed traffic data. Since the multiplicative factors for 1975 and
1985 were both equal to 0.029, it was assumed that the same factor would be appro-
priate for 1980. Lacking better information, the multiplicative factor for 1990 (0.026)
was interpolated from factors for 1985 and 1995. Here, it was assumed that there
would be gradual changes in the transportation network from 1985 to 1995. The multi-
plicative factor for 2000 was taken to be the same as that for 1995. Here, it was
assumed that there would not be any changes in the transportation network from 1995
to 2000.
Total CO emissions for Phoenix in 1980, 1990, and 2000 as well as peak 8-hour CO
readings with or without additional control strategies other than traffic system
improvements, improved mass transit and regional development planning are presented
in Table 21. No data was presented for the implementation of dealer emissions control
maintenance guarantee, clean air rebate, vapor recovery, bicycle systems and work and
driving schedule shifts because there were insignificant reductions in the resultant
emissions.
The predicted peak CO readings in 1980 were all higher than the 8-hour CO
standard while all predicted peak CO readings in 1990 were below the standard. In
2000, the peak value was higher than the standard for the base case, i.e., with only
traffic system improvements, improved mass transit and regional development planning,
but the peak reading with any additional control strategy was lower than the standard.
PREDICTED ATTAINMENT YEARS FOR CO
Figure 25 shows the relative magnitude of the predicted peak 8-hour CO readings
for the various study years and their relation to the National Standard (9 ppm). This
figure was used to approximate the years of attainment of the standard with various
combinations of control strategies. These attainment years are presented in Table 22 to
serve as an aid in assessing the relative effectiveness of the various control strategy
combinations. Bearing in mind that model predictions are good to + 2 ppm, the year of
attainment could change by as much as + 3 years.
68
-------
Table 21. CO EMISSIONS AND PEAK 8-HOUR CO READINGS IN 1980, 1990 AND 2000
FOR DIFFERENT CONTROL STRATEGIES
Control Strategy
Base Case
Base Case plus Inspection/Maintenance
Base Case plus Periodic Maintenance
Base Case plus Carpooling
Base Case plus I/M and Carpooling
Base Case plus PM and Carpooling
1980
Emissions^
(tons/day)
676.0
551.3
453.7
661.1
539.7
444.1
Peak CO3
Reading (ppm)
19.6
16.0
13.1
19.1
15.7
12.9
1990
Emissions
(tons/day)
331.2
284.3
232.3
318.3
275.1
224.6
Peak CO
Reading (ppm)
8.6
7.4
6.0
8.3
7.1
5.8
2000
Emissions
(tons/day)
430.2
364.3
302.9
400.7
342.7
283.9
Peak CO
Reading (ppm)
9.9
8.4
7.0
9.2
7.9
6.5
1
2
Base Case includes traffic system improvements, improved mass transit
and regional development planning.
Total emissions corresponding to a peak 8-hour CO reading of 9 ppm would be 310.3 tons/day in 1980,
346.2 tons/day in 1990, and 391.3 tons/day in 2000.
National CO 8-hour standard is 9 ppm.
-------
35
O
U
I
00
m
cu
Base Case
Base Case + Carpooling
Base Case + I/M
Base Case + I/M + Carpooling
Base Case -t- PM
Base Case + PM + Carpooling
1975
Figure 25.
1980
1985
199O
1995
2OOO
Year
Predicted peak 8-hour CO concentrations in ppm under
various combinations of control strategies.
70
-------
Table 22. YEARS OF ATTAINMENT OF THE CO STANDARD FOR DIFFERENT CONTROL STRATEGIES.
Control Strategy
Base Case (Transportation System Improvements, Improved
Mass Transit and Regional Development Planning)
Base Case
Base Case
Base Case
Base Case
Base Case
+ Inspection/Maintenance
+ Periodic Maintenance
+ Carpooling
+ Inspection/Maintenance + Carpooling
+ Periodic Maintenance + Carpooling
Year of Attainment
of the CO Standard
1990
1988
1985
1990
1987
1984
Maintained
through year
1996
2000+
2000+
1998
2000+
2000+
-------
A SUMMARY OF CO AIR QUALITY
The main findings of this chapter are presented in this section.
The APRAC-H model, after it was calibrated for the Phoenix area, was used to
determine spatial variations in CO concentrations, to pinpoint hot spots and to calculate
the highest 8-hour CO concentration for the base year emissions scenario. It was also
used to simulate CO air quality for the 1985 and 1995 scenarios with only the basic
control strategies of traffic system improvements, improved mass transit and regional
development planning, as well as with additional control strategies of inspection/main-
tenance and carpooling.
From results of these simulations, it was evident that one could relate peak 8-hour
CO readings to emissions. This is not surprising since CO is an inert pollutant and
therefore, given the same meteorology, X /Q (where X is the concentration and Q the
emissions) must be conserved provided the relative distribution of Q is the same. Values
of X/Q for different years of interest, 1980, 1985, 1990, 1995 and 2000 were developed
and peak 8-hour CO readings were computed for different scenarios of emissions.
No attainment of the standard was predicted for the 1980 case with any proposed
control strategy, or combination of control strategies, in effect. For the 1985 case, the
addition to the base case of periodic maintenance or periodic maintenance and
carpooling would be the only controls that would bring the peak CO reading to less than
the standard. With only the three basic control strategies of traffic system improve-
ments, improved mass transit and regional development planning, it was determined
that the 8-hour CO standard would be attained for the 1990 scenario, and maintained
for 1995 but not for the 2000 scenario. The addition of carpooling alone would give the
same result. If any one of inspection/maintenance, periodic maintenance, inspection/
maintenance and carpooling, or periodic maintenance and carpooling, were implemented
with the base case, the CO standard would be maintained for both the 1995 and 2000
scenarios.
Emission reductions obtained from the implementation of dealers emissions
control maintenance guarantee, clean air rebate, vapor recovery, bicycle systems, and
work and driving schedule shifts were determined to lead to a negligible improvement in
CO air quality.
72
-------
VIII. PHOTOCHEMICAL OXIDANT AIR QUALITY PRO3ECTIONS
Photochemical oxidant is a secondary pollutant. In other words, it is not emitted
by any source. Rather, it is formed when hydrocarbons and nitrogen oxides in the
ambient air are irradiated by sunlight. Therefore, to reduce the concentration of
oxidant would require controlling the emissions of oxidant precursors.
The Environmental Protection Agency has developed an approach whereby one can
approximate the reduction in non-methane hydrocarbon emissions (NMHC) required to
attain the 1-hour oxidant standard of 160 vg/m . This approach is known as the
Appendix 3 method (Appendix 3. 40CFR, Part 51) and is used here to evaluate the
^effectiveness of proposed control strategies in the maintenance of oxidant air quality in
Phoenix.
The second highest oxidant reading in 1975 was 259 yg/m - Based on Figure 26,
:tbe essence of the Appendix 3 method, the reduction in NMHC emissions required to
maintain the oxidant standard is 38%. The total NMHC emissions in Phoenix in 1975
;*ere 221.7 tons/day (see Chapter IV). This implies that the maximum allowable NMHC
emissions for maintenance of the oxidant standard is 137.5 tons/day. A linear rollback
method of determining maximum allowable emissions would lead to approximately the
same result.
Non-methane HC emissions in the Phoenix Metropolitan Area at five year
intervals from 1985 to 2000 with only the strategies that are in the MAG regional plan,
'{traffic system improvements, improved mass transit and regional development
Jfcbnning) as well as with additional proposed strategies were presented in Chapter VI.
Figure 27 shows these emission levels and compares them with the maximum
allowable emission level of 137.5 tons/day. Without additional control, the air quality
standard would be attained by 1986 and maintained thereafter. Implementation of any
Of the control strategies shown in the figure would expedite the attainment and
inaintenance of the oxidant standard. The addition of carpooling or vapor recovery
would result in attainment in 1985. The addition of inspection/maintenance or periodic
maintenance would lead to attainment in 1982.
73
-------
I
II
(H Ğ Ğ
3 X
12
If
I?
s°
£*
Ğ* ?3
"5,-S
c
II
0)
100
0.1O
Maximum Measured 1-Hour Photochemical Oxidant Concentration ppm
O.15 0.20 0.25 050
150 200 250 300 350 400 450 500
Maximum Measured I -Hour Photochemical Oxidant Concentration, ug/m
550
3
600
Figure 26. Required hydrocarbon emission control as a function of photochemical oxidant concentration.
Maximum allowable NMHC emissions = 137.5 tons/day (Reference: Air Quality Criteria for
Nitrogen Oxides AP 84 EPA. Washington. D.C.. January 1971.)
-------
200
Base Case
Carpooling
Vapor Recovery
Inspection/Maintenance
Periodic Maintenance
i
CO
i
100
150
MAXIMUM ALLOWABLE EMISSIONS
70
^_
1975
Figure 27.
1980
1985 1990
Year
1995
2000
NMHC emissions (tons/day) under various control
strategies (base case incorporates strategies in
regional plan only).
75
-------
Other control strategies proposed, i.e., dealer emissions control maintenance
guarantee, clean air rebate, bicycle systems and work and driving schedule shifts, do not
have any significant effect on the NMHC emissions inventory. Then implementation
would, therefore, not result in an noticeable improvement in oxidant air quality.
The effect of implementing more than one additional control strategy is
illustrated in Figures 28 through 31. Inspection/maintenance and periodic maintenance
cannot co-exist. Therefore, there are seven combinations of different additional
control strategies, namely (1) inspection/maintenance and carpooling, (2) periodic
maintenance and carpooling, (3) inspection/maintenance and vapor recovery, (4) periodic
maintenance and vapor recovery, (5) inspection/maintenance, carpooling and vapor
recovery, (6) periodic maintenance, carpooling and vapor recovery, and (7) carpooling
and vapor recovery. Combination (1) and (2) would lead to attainment of the oxidant
standard in 1982; combinations (3) through (6) in 1981 and combination (7) in 1984.
Inspection/maintenance or periodic maintenance are nearly interchangeable in the
combinations with periodic maintenance showing only a slight advantage.
A summary of the attainment years for all proposed control strategies that result
in a significant reduction in NMHC emissions is presented in Table 23. According to the
Appendix J approach, the oxidant standard would be maintained from date of
attainment through the year 2000.
76
-------
200
Base Case
Base Case + I/M + Carpooling
Base Case + PM + Carpooling
I
W
I
MAXIMUM ALLOWABLE EMISSIONS
1975
1980
1985 1990
Year
1995
2000
Figure 28. NMHC emissions (tons/day) under various combinations
of control strategies utilizing carpooling.
77
-------
2OO
150
i
CO
g
Ğ
1U
u
Base Case + I/M + Vapor Recovery
Base Case + PM + Vapor Recovery
MAXIMUM ALLOWABLE EMISSIONS
1OO
1975
Figure 29.
1980
1985 1990
Year
1995
2000
NMHC emissions (tons/day) under various combinations
of control strategies utilizing vapor recovery.
78
-------
200
150
i
<0
I
CO
Ul
u
5
100
1975
Base Case
Base Case + I/M + Car pooling
Vapor Recovery
Base Case + PM + Car pool ing +
Vapor Recovery
MAXIMUM ALLOWABLE EMISSIONS
1980
1985 1990
Year
1995
2000
Figure 30. NMHC emissions (tons/day) under various combinations
8 of control strategies utilizing vapor recovery and
carpooling.
79
-------
20O
Base Case
Base Case + Carpooling +
Vapor Recovery
MAXIMUM ALLOWABLE EMISSIONS
1975
1980
1985
1990
1995
200O
Figure 31. NMHC emissions (tons/day) for the base case and carpooling
and vapor recovery in addition to base case.
80
-------
Table 23. YEARS OF ATTAINMENT OF THE OXIDANT STANDARD FOR
DIFFERENT CONTROL STRATEGIES.
Control Strategy
Year of Attainment .
of the Oxidant Standard^
Base Case (Traffic System Improvements, Improved
Mass Transit and Regional Development Planning)
Base Case + Inspection/Maintenance
Base Case + Periodic Maintenance
Base Case + Carpooling
Base Case + Vapor Recovery
Base Case + Inspection/Maintenance + Carpooling
Base Case + Periodic Maintenance + Carpooling
Base Case + Inspection/Maintenance + Vapor Recovery
.Base Case + Periodic Maintenance + Vapor Recovery
Base Case + Inspection/ Maintenance + Carpooling + Vapor Recovery
I
Base Case + Periodic Maintenance + Carpooling + Vapor Recovery
Case + Carpooling + Vapor Recovery
1986
1982
1982
1985
1985
1982
1982
1981
1981
1981
1981
Oxidant standard will be maintained through 2000 for all control strategies.
-------
IX. CONCLUSIONS
Maximum 8-hour CO readings were predicted for 1980, 1985, 1990, 1995 and 2000.
When only the basic control strategies of traffic system improvements, improved mass
transit and regional development planning were implemented, the maximum 8-hour CO
readings for all but the 1990 and 1995 cases were greater than the national standard of
9 ppm. The additional control strategies that are effective in reducing CO emissions
are inspection/maintenance, periodic maintenance, carpooling, inspection/maintenance
and carpooling, and periodic maintenance and carpooling. The implementation of any of
these additional strategies, except carpooling, would bring about the maintenance of CO
standard in 2000. For the 1980 case, no attainment of the standard was predicted no
matter what control strategies were implemented. For the 1985 case, the addition of
periodic maintenance or periodic maintenance and carpooling would bring the peak CO
reading to less than the standard.
With the three basic control strategies, the oxidant standard would be attained by
1986 and maintained through 2000. The addition of any control strategy would expedite
the attainment and prolong the maintenance of the standard. No matter what
strategies were implemented, the oxidant standard would not be attained before 1981.
Table 24 summarizes carbon monoxide and oxidant standard attainment years
under various control strategies.
The most effective method of attaining the CO and oxidant standards would be by
the implementation of periodic maintenance and carpooling, in addition to the three
basic strategies. Since inspection/maintenance has already been implemented,
conversion to periodic maintenance would require serious study and consideration of
cost effectiveness and socio-economic impact. Although dealer emissions control
maintenance guarantee and clean air rebate do not themselves contribute directly to
CO or NMHC emission reductions, they provide incentive to the conduct of
inspection/maintenance or periodic maintenance. Acceptability of these two strategies
by the general public should be high.
82
-------
Table 2Ğ. CARBON MONOXIDE AND OXIDANT ATTAINMENT AND MAINTENANCE YEARS.
CONTROL STATEGY
Base Case
Base Case
Base Case
Base Case
Base Case
Base Case
Base Case
Base Case
Base Case
Base Case
Base Case
Base Case
+ Carpooling
+ I/M
+ Carpooling + I/M
+ PM
+ Carpooling + PM
+ I/M + Vapor Recovery
-i- PM + Vapor Recovery
+ I/M + Carpooling + Vapor Recovery
+' PM + Carpooling + Vapor Recovery
+ Carpooling + Vapor Recovery
+ Vapor Recovery
CO
Attainment
Year
1990
1990
1988
1987
1985
198*
-
-
-
-
-
-
Maintained
Through
Year
1996
1998
2000+
2000+
2000+
2000+
-
-
-
-
-
-
Oxidant
Attainment
Year
1986
1985
1982
1982
1982
1982
1981
1981
1981
1981
1984
1985
oe
Oxidant standard will be maintained through 2000 for all control strategies.
-------
X. REFERENCES
Arizona State Department of Economic Security. Population Estimate of Arizona.
(1976).
Arizona State Department of Health. Transportation Control Strategies. Supplement
to the Arizona State Implementation Plan. 1973.
Gockel, 3.L. An Evaluation of the Effectiveness of Automobile Engine Adjustments to
Reduce Exhaust Emissions and an Evaluation of the Training Required to Develop
Personnel Competent to Make the Adjustments. Clean Air Research Company.
California Air Resources Contract No. 654. 1973.
Maricopa Association of Governments. Approved Regional Transportation Plan. 1976.
Maricopa Association of Governments. Composite Land Use Plan for Maricopa County.
1976.
Maricopa Association of Governments. Five Year Transit Development Program, Fiscal
Years 1977-1981. In Cooperation with U.S. Department of Transportation-
Federal Highway Adminstration and Urban Mass Transportation Administration.
October, 1976.
Pacific Environmental Services, Inc. Emission Inventory Report for the Phoenix Study
Area 1975-1995. 1976.
Wanning Environment International. San Diego Air Quality Planning Report. 1976.
U.S. Environmental Protection Agency. Air Quality Criteria for Nitrogen Oxides. EPA
Publication No. AP-84. 1971.
U.S. Environmental Protection Agency. Guideline for the Interpretation of Air Quality
Standards. 1974.
U.S. Environmental Protection Agency. Compilation of Air Pollutant Emission Factors.
Second Edition, EPA Publication No. AP-42, and Supplement 5 to the same publi-
cation. 1975.
lf.S. Environmental Protection Agency. National Emissions Data System, County
Emissions Report, Maricopa County, Arizona. 1976.
Withersooon G. An Investigation into the Feasibility of Reducing Hydrocarbon
EmSions from Gasoline8 Evaporation Sources in Maricopa County. Maricopa
County Department of Health Services, Bureau of Air Pollution Control.
September, 1976.
-------
APPENDIX A
Traffic Emissions - Base Year (1975)
and Projections for 1985 and 1995
-------
This appendix presents details of traffic emission computation for the years 1975,
1985, and 1995.
METHODOLOGY
Traffic data for the 1975, 1985 and 1995 systems were provided by the Trans-
portation and Planning Office of the Maricopa Association of Governments. Population
levels of 1.7 million and 2.2 million were used for projecting the 1985 and 1995 traffic
systems respectively.
The volume, link length and capacity for each link in each roadway network were
read off the loaded historical record of traffic assignments. This information was
processed through a computer by means of AVSUP5, a computer program developed by
AeroVironment to compute emissions from highway vehicles according to procedures
outlined in Compilation of Air Pollutant Emission Factors, AP42 (U.S. EPA, 1976).
The averaged daily volume on each link was divided into hourly volumes according
to the percent ADT by facility type presented in Table A-l. These percentages were
derived from actual counts taken during January, 1974, at a freeway and arterial station
in Phoenix. Traffic counts during other periods show very similar percentages.
The hourly volume was further stratified into five types of vehicles by facility
type (Table A-2). These five types of vehicles are light-duty gasoline-powered
passenger cars and trucks, light-duty dieseJ-powered vehicles, and heavy-duty gasoline-
powered and diesel-powered trucks. As in Supplement 5 to AP42, light-duty vehicles
are vehicles rated at less than 8500 pounds gross vehicle weight while heavy-duty
vehicles are vehicles rated at more than 8500 pounds gross vehicle weight. The
stratification between light-and heavy-duty vehicles by hour was obtained from actual
class counts on a Phoenix freeway and arterial in April 1972. Subdivisions into different
classes of light- and heavy-duty vehicles was obtained from 1976 vehicle registration
records in Maricopa County. Furthermore, based on registration records, the
motorcycle population was assumed to be equivalent to 4.11% of the total number of
other vehicles. Also, the ratio of motorcycle VMT to light duty vehicle VMT is 1/6.66
based on AP-42 (U.S. EPA, 1976).
A-l
-------
Table A-l. PERCENT ADT BY FACILITY TYPE FOR PHOENIX (1974).
Hour
0
1
2
3
4
5
6
7
8
9
10
11
12
13
I*
15
16
17
18
19
20
21
22
23
Freeways
1.3
.8
.5
.5
.6
1.3
4.5
9.4
7.7
5.3
4.9
4.9
4.8
5.0
5.7
7.1
9.4
8.5
5.0
3.7
2.5
2.4
2.3
1.9
Arterials
1.6
.8
.3
.2
.2
.6
3.1
8.1
6.5
4.8
4.9
5.5
6.1
6.0
6.0
7.5
8.8
8.2
5.4
3.9
3.1
3.4
2.7
2.3
A-2
-------
Table A-2. LIGHT AND HEAVY-DUTY VEHICLE STRATIFICATION BY
HOUR AND FACILITY TYPE.
Hour
0
1
2
3
4
5
6
7
8
9
10
11
12
13
1*
15
16
17
18
19
20
21
22
23
Light Duty
LD Vehicle LD Truck
Gas
Fwy.
75.20
70.43
66.**
66.44
68.03
72.03
73.64
73.64
6S.S3
6S.83
69.63
70.43
72.03
71.23
72.03
74.43
76.84
78.44
77.64
76.84
77.64
76.84
77.64
76.84
Art.
77.64
76.04
73.63
72.03
73.63
76.04
78.44
77.64
72.83
72.83
71.23
72.03
72.03
72.03
72.83
74.43
76.84
77.64
76.84
76.04
76.84
75.24
77.64
78.44
Diesel
Fwy.
.03
.03
.02
.02
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
Art.
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
.03
Gas
Fwy.
18.72
17.53
16.53
16.53
16.93
17.93
18.33
18.33
17.13
17.13
17.33
17.53
17.93
17.73
17.93
18.53
19.12
19.52
19.32
19.12
19.32
19.12
19.32
19.12
Art.
19.32
18.92
18.33
17.93
18.33
18.92
19.52
19.32
18.13
18.13
17.73
17.93
17.93
17.93
18.13
18.53
19.12
19.32
19.12
18.92
19.12
18.72
19.32
19.52
Diesel
Fwy.
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
Art.
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
Heavy Duty
Gas j
Fwy.
*.7*
9.48
13.43
13.43
11.85
7.90
6.32
6.32
11.06
11.06
10.27
9.*8
7.90
8.69
7.90
5.53
3.16
1.58
2.37
3.16
2.37
3.16
2.37
3.16
Art.
2.37
3.95
6.32
7.90
6.32
3.95
1.58
2.37
7.11
7.11
8.69
7.90
7.90
7.90
7.11
5.53
3.16
2.37
3.16
3.95
5.16
*.7*
2.37
1.58
Diesel
___
1.26
2.52
3.57
3.57
3.15
2.10
1.6S
1.68
2.9*
2.9*
2.73
2.52
2.10
2.31
2.10
l.*7
0.8*
0.*2
0.63
0.8*
0.63
0.8*
0.63
0.8*
Art.
0.63
1.05
1.68
2.10
l.CS
1.05
0.*2
0.63
1.89
1.S9
2.31
2.10
2.10
2.10
1.89
l.*7
0.8*
0.63
0.8*
1.05
0.8*
1.26
0.63
0.*2
A-3
-------
The speed on each link was assumed to be a function of the ratio of volume to
capacity. The variation of average speed with volume to capacity ratios by functional
class by area type is presented in Table A-3, which was obtained from Special Area
Analysis, a document prepared by the Federal Highway Administration (1973). However,
to reflect reality, a speed limit of 55 mph instead of 65 mph was assumed for freeways
in the suburbs.
The emission due to primary traffic along each link was then computed as a sum
of emissions contributed by each type of vehicle. For each vehicle type, emission was
calculated as follows: E = eV where E is the total emission, e is the emission factor and
V is the vehicle-miles traveled, which is the product of the vehicle volume and the link
length. The emissions for a system was then calculated as the sum of emissions for
each link.
It was assumed that in addition to emissions from traffic on the roadway network,
there were emissions from secondary traffic which consisted of light-duty vehicles with
an amount equivalent to 1*% of the primary traffic and a speed of 20 mph.
Table A-4 presents motor vehicle emissions of CO and NMHC by vehicle type for
1975, 1985 and 1995. In calculating these emissions, emission factors for the different
types of vehicles were computed according to the procedures in Supplement 5 to AP42
as follows. In determining the methane (non-reactive) content of automobile emissions,
the 6-class reactivity scheme of Trijonis and Arledge (1975) was used. This
classification scheme is presented in Table A-5.
LIGHT-DUTY, GASOLINE-POWERED VEHICLES
The calculation of composite emission factors for light-duty vehicles is given by
n
enpstwx = .Ğ . - cipn in ips ipt iptwx
where: e = Composite emission factor in grams per mile (g/km) for
ilpST Inr X
calendar year (n), pollutant (p), average speed (s), ambient
temperature (t), percentage cold operation (w), and percent-
age hot start operation (x).
-------
Table A-3. VARIATION OF AVERAGE SPEED WITH VOLUME TO CAPACITY
RATIOS (V/C) BY FUNCTIONAL CLASS BY AREA TYPE.
V/C
0
.1
.2
.3
A
.5
.6
.7
.8
.9
1.0
1.1
1.2
1-3
1 A
1.5
1.6
Average Speed (mph)
Freeways
CBD/CC 2
50.0
48.0
46.0
44.0
42.0
40.0
38.0
36.0
34.0
32.0
30.0
27.0
24.0
21.0
18.0
15.0
15.0
Sub3
55.0
52.5
50.0
48.0
46.0
44.0
41.0
39.0
36.0
33.0
30.0
27.0
24.0
21.0
18.0
15.0
15.0
Arterials 1
CBD
21.8
21.3
20.8
20.3
19.8
19.3
18.8
18.3
17.8
16.4
15.0
13.0
11.0
9.0
7.0
5.0
3.0
CC
29.8
29.5
29.2
28.8
28.5
28.2
27.8
27.5
27.2
21.1
15.0
13.0
11.0
9.0
7.0
5.0
3.0
Sub
32.2
32.0
31.8
31.6
31.4
31.2
31.0
30.8
30.6
22.8
15.0
13.0
11.0
9.0
7.0
5.0
3.0
1
2
Parkways and expressways are categorized as arterials for speed determinations.
CBD: Central Business District.
CC: Central City.
Sub: Suburban.
A-5
-------
Table A-*. REVISED EMISSION INVENTORIES FOR 1975, 1985 AND 1995.
Emission Sources
Primary Traffic
Light Duty Autos
Light Duty Trucks
Heavy Duty Gas Trucks
Light Duty Diesel Trucks
Heavy Duty Diesel Trucks
Motorcycles
Subtotal
Secondary Traffic
TOTAL
1975
CO
tons/day
607.1
182.3
1*1.7
<0.1
4.0
3.3
938.3
1*8.*
1086.7
NMHC
tons/day
80.0
30.6
19.1
<0.1
0.7
0.9
131.*
20.3
151.7
1985
CO
tons/day
116.3
67.1
123.7
<0.1
5.3
*.2
316.6
*7.6
36*. 2
NMHC
tons/day
32.8
15.1
11.*
<0.1
1.1
0.9
61.2
9.2
70.*
1995
CO
tons/day
65.*
57.2
155.*
<0.1
7.2
1.6
286.9
31.7
318.6
NMHC
tons/day
21.9
11.1
12.7
<0.1
1.5
0.5
*7.7
6.5
5*.l
-------
Table A-5. DISTRIBUTION (IN %) OF ORGANIC COMPOUNDS IN A 6-CLASS REACTIVITY SCHEME.
>
Source Category
Mobile Sources
Light Duty Gasoline Powered Vehicles
Exhaust Emissions
Evaporative Emissions
Heavy Duty Gasoline Powered Vehicles
Exhaust Emissions
Evaporative Emissions
Other Gasoline Powered Equipment
Exhaust Emissions
Evaporative Emissions
Diesel Powered Vehicles
Mole (%)
Class 0
-------
c-
ipn
Emission factor for the ith model year light-duty vehicles
during calendar year (n) and for pollutant (p).
m._ = The fraction of annual travel by the i* model year light-duty
vehicles during calendar year (n)
in
v. = The speed correction factor for the i model year light-duty
vehicles for pollutant (p), and average speed (s). This variable
applies only to CO, HC, and NOx-
z = The temperature correction for the i model year light-duty
ipt
vehicles for pollutant (p) and ambient temperature (t)
r.
The hot/cold vehicle operation correction factor for the i
iptwx
model year light-duty vehicles for pollutant (p), ambient
temperature (t), percentage cold operation (w), and percent-
age hot start operation (x).
The variable c. is summarized in Table A-6. The input m. is presented in Table A-7.
ipn m
The speed correction factors are presented in Tables A-8 and A-9. The temperature
correction and hot/cold vehicle operation correction factors are given in Table A-10.
The 1975 Federal Test Procedure average values of 20% cold operation, 27% hot start-
up condition and 53% hot stabilized condition were assumed, since no other information
was available.
In addition to exhaust emission factors, the calculation of hydrocarbon
emissions from gasoline motor vehicles involves evaporative and crankcase hydrocarbon
emission factors. Composite crankcase emissions were determined using:
n
himin
i=n-12
where: f = the composite crankcase hydrocarbon emission factor
for calendar year (n)
A-8
-------
Table A-6. CARBON MONOXIDE AND HYDROCARBON EXHAUST EMIS-
SION FACTORS FOR LIGHT-DUTY, GASOLINE-POWERED
VEHICLES FOR CALENDAR YEARS 1975, 1985 AND 1995.
Pollutant
CaJenda
Model Year
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
197*
1975
1976
1977
197S
1979
1980
1981
1982
1983
198*
1985
1986
1987
1988
1989
1990
1991
1992
1993
199*
1995
Light Duty Gasoline Powered Vehicles
FTP Exhaust Emission Rates Cg/mile)
CO
r Year
1975
96.0
96.0
96.0
96.0
96.0
73.6
71.*
61.0
58.5
*3.0
*1.0
39.0
9.0
19S5
57.0
57.0
18.0
17.1
16.2
4.8
*.5
*.2
3.9
3.6
3.*
3.1
2.8
1995
5.6
5.6
5.6
5.3
5.0
*.8
t.5
4.2
3.9
3-6
3.4
3.1
2.8
HC
1975
9.0
9.0
9.0
9.0
9.0
8.0
6.3
6.3
5.1
4.1
3.8
3.5
1.0
1985
6.2
6.2
3.0
2.8
2.6
0.7
0.6
0.5
0.5
0.4
0.*
0.3
0.3
1995
0.8
0.8
0.8
0.8
0.7
0.7
0.6
0.5
0.5
0.4
0.4
0.3
0.3
A-9
-------
Table A-7. FRACTION OF ANNUAL LIGHT-DUTY GASOLINE POWERED
VEHICLE TRAVEL BY MODEL YEAR.
Age
Years
1
2
3
4
5
6
7
8
9
10
11
12
> 13
Fraction of Total
Vehicles in Use
(a)
.066
.089
.111
.105
.084
.084
.085
.071
.062
.059
.052
.038
.094
Average Annual
Miles Driven (b)
15,900
15,000
14,000
13,100
12,200
11,300
10,300
9,400
8,500
7,600
6,700
6,700
6,700
a x b
1,049
1,335
1,554
1,376
1,025
949
876
667
527
448
348
255
630
Fraction
of Annual
Travel (m (axb) )
1 ravel im-z
-------
Table A-8. COEFFICIENTS FOR SPEED CORRECTION FACTORS FOR LIGHT-DUTY GASOLINE POWERED
VEHICLES AND TRUCKS.1
Location
Low Altitude
Model
Year
1957-1967
1968
1969
1970
Post- 1970
(A + BS + CS2)
v = e
Hydrocarbons
A
0.953
1.070
1.005
0.901
0.943
B
-6.00 x 10"2
-6.63 x 10"2
-6.27 x 10"2
-5.70 x 10"2
-5.92 x 10"2
C
5.81 x 10"*
5.98 x 10"*
5.80 x 10"*
5.59 x 10"*
5.67 x 10"*
Carbon Monoxide
A
0.967
1.047
1.259
1.267
1.241
B
-6.07 x 10"2
-6.52 x 10'2
-7.72 x 10"2
-7.72 x 10"2
-7.52 x 10"2
C
5.78 x 10"*
6.01 x 10"*
6.60 x 10"*
6.40 x 10"*
6.09 x 10"*
Equations should not be extended beyond the range of the data (15 to 45 mph). For speed correction factors
at low speeds (5 and 10 mph) see Table A-9.
-------
Table A-9. LOW AVERAGE SPEED CORRECTION FACTORS FOR LIGHT-DUTY GASOLINE POWERED
VEHICLES AND TRUCKS.
f
to
Location
Low Altitude
Model
Year
1957-1967
1968
1969
1970
Post- 1970
Carbon Monoxide
5 mi/hr
(8 km/hr)
2.72
3.06
3.57
3.60
4.15
10 mi/hr
(16 km/hr)
1.57
1.75
1.86
1.88
2.23
Hydrocarbons
5 mi/hr
(8 km/hr)
2.50
2.96
2.95
2.51
2.75
10 mi/hr
(16 km/hr)
1.45
1.66
1.65
1.51
1.63
-------
Table A-10. LIGHT-DUTY, GASOLINE-POWERED VEHICLE AND TRUCK TEMPERATURE CORRECTION
FACTORS AND HOT/COLD VEHICLE OPERATION CORRECTION FACTORS FOR FTP
EMISSION FACTORS.
Pollutant
and Controls
Carbon monoxide
Non-catalyst
Catalyst
Hydrocarbons
Non-catalyst
Catalyst
Temperature
Correction Factor
-0.0127t + 1.95
-0.07*3t + 6.58
-0.0113t + 1.81
-0.030*t + 3.25
Hot/Cold Vehicle Operation
Correction Factors *
g
-------
h. = The crankcase emission factor for the i model year
m. = The weighted annual travel of the i* model year
during calendar year (n)
Crankcase hydrocarbon emission factors by model year are summarized in Table A-ll.
There are two sources of evaporative hydrocarbon emissions from light-duty
vehicles: the fuel tank and the carburetor system. Diurnal changes in ambient
temperature result in expansion of the air-fuel mixture in a partially filled fuel tank.
As a result, gasoline vapor is expelled to the atmosphere. Running losses from the fuel
tank occur as the fuel is heated by the road surface during driving, and hot soak losses
from the carburetor system occur after engine shutdown at the end of a trip.
Carburetor system losses occur from such locations as the carburetor vents, the float
bowl, and the gaps around the throttle and choke shafts. Because evaporative emissions
are a function of the diurnal variation in ambient temperature and the number of trips
per day, emissions are best calculated in terms of evaporative emissions per day per
vehicle. Emissions per day can be converted to emissions per mile (if necessary) by
dividing the emissions per day by an average daily miles per vehicle value. This value is
likely to vary from location to location, however, The composite evaporative
hydrocarbon emission factor is given by:
n
en = L
i=n-12
where: e = The composite evaporative hydrocarbon emis-
sion factor for calendar year (n) in Ibs/day
(g/day)
g. = The diurnal evaporative hydrocarbon emission
factor for model year (i) in Ibs/day (g/day)
k = The hot soak evaporative emission factor in
i th
Ibs/trip (g/trip) for the i model year
A-l*
-------
Table A-l 1. CRANK CASE HYDROCARBON EMISSIONS BY MODEL YEAR
FOR LIGHT-DUTY GASOLINE POWERED VEHICLES.
Model
Year
Low Altitude
Pre-1963
1963 through 1967
Post- 1967
Hydrocarbons
g/mi
4.1
0.8
0.0
g/km
2.5
0.5
0.0
A-15
-------
d = The number of daily trips per vehicle (a
nationwide average of 3.3 trips/vehicle/day was
used)
rn. = The weighted annual travel of the i model
year during calendar year (n)
The variables g. and K. are presented in Table A-12 by model year.
LIGHT-DUTY, GASOLINE-POWERED TRUCKS
The composite emission factor for light-duty trucks is given by:
n
enpstwx = *-* Cipn min vips zipt riptwx
i=n-12
where: enDStwx = Composite emission factor in g/mi (g/km) for
calendar year (n), pollutant (p), average speed
(s), ambient temperature (t), percentage cold
operation (w), and percentage hot start opera-
tion (x)
c. = The 1975 Federal Test Procedure mean emis-
lpn th
sion factor for the i model year light-duty
trucks during calendar year (n) and for pollut-
ant (p)
m. = The fraction of annual travel by the i model
year light-duty trucks during calendar year (n)
v. = The speed correction factor for the i model
year light-duty trucks for pollutant (p) and
average speed (s)
A-16
-------
Table A-12. EVAPORATIVE HYDROCARBON EMISSIONS BY MODEL
YEAR FOR LIGHT-DUTY GASOLINE-POWERED VEHICLES.
Location and
Model Year
Low Altitude
Pre-1970
1970
1971
1972-1979
Post- 1979
By Source
Diurnal
g/day
26.0
26.0
16.3
12.1
-
Hot soak
g/trip
14.7
14.7
10.9
12.0
-
Composite
g/day
74.5
74.5
52.3
51.7
-
g/mi
2.53
2.53
1.78
1.76
0.5
g/km
1.57
1.57
1.11
1.09
0.31
A-17
-------
z. = The temperature correction for the i model
year light-duty trucks for pollutant (p) and
ambient temperature (t)
r = The hot/cold vehicle operation correction f ac-
iptwx +h . *
tor for the i model year light-duty trucks for
pollutant (p), ambient temperature (t), per-
centage cold operation (w), and percentage hot
start operation (x)
Emission factors for light-duty trucks are summarized in Table A-13. Values for
min are given in Table A-14. vips, z.^, and riptwx are the same for this class as
for light-duty vehicles (see Tables A-8, A-9, and A-10).
In addition to exhaust emission factors, evaporative crankcase hydrocarbon
emissions for light-duty trucks were determined using:
n
i=n-12
himin
where: f
n
The combined evaporative and crankcase hy-
drocarbon emission factor for calendar year (n)
h. = The combined evaporative and crankcase hy-
drocarbon emission rate for the i model
year. Emission factors for this source are
reported in Table A-15. The crankcase and
evaporative emissions reported in the table are
added together to arrive at this variable.
m. = The weighted annual travel of the i model
in
year vehicle during calendar year (n)
A-18
-------
Table A-13. CARBON MONOXIDE AND HYDROCARBONS EXHAUST
EMISSION FACTORS FOR LIGHT-DUTY, GASOLINE-POWERED
TRUCKS FOR CALENDAR YEARS 1975, 1985 AND 1995.
Pollutant
Calendar Y
Model Year
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
J973
197*
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
Light Duty Gasoline Powered Trucks
FTP Exhaust Emission Rates
CO
1975
125.0
125.0
125.0
125.0
125.0
77.0
74.8
61.0
61.0
49.4
47.2
45.0
27.0
1985
64.8
64.8
42.0
40.5
39.9
16.8
15.8
14.8
13.8
12.8
11.8
10.8
9.8
1995
19.8
19.8
19.8
18.8
17.8
16.8
15.8
14.8
13.8
12.8
11.8
10.8
9.8
HC
1975
17.0
17.0
17.0
17.0
17.0
9.5
7.1
6.6
5.7
4.6
4.4
4.0
2.7
1985
7.6
7.6
5.7
5.4
5.1
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
1995
3.0
3.0
3.0
2.8
2.6
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
A-19
-------
Table A-l*. FRACTION OF ANNUAL LIGHT-DUTY GASOLINE-POWERED
TRUCK TRAVEL BY MODEL YEAR.
Age,
Years
1
2
3
*
5
6
7
8
9
10
11
12
> 13
Fraction of Total
Vehicles in Use
(a)
.063
.096
.122
.106
.070
.072
.071
.052
.0*7
.0*6
.0*2
.039
.17*
Average Annual
Miles Driven (b)
15,900
15,000
1*,000
13,100
12,200
11,300
10,300
9,*00
8,500
7,600
6,700
6,700
6,700
a x b
1,002
1,**0
1,708
1,389
85*
81*
731
*89
*00
350
281
261
1,166
Fraction
of Annual
Travel (m-
-------
table A-15. CRANKCASE AND EVAPORATIVE HYDROCARBONS EMISSION FACTORS ftğK Lion i -uu i r,
GASOLINE-POWERED TRUCKS.
K)
Location
Low Altitude
Model
Years
Pre-1963
1963-1967
1968-1970
1971
1972-1979
Post-1979
Crankcase Emissions
g/km
2.9
1.5
0.0
0.0
0.0
0.0
g/mi
4.6
2.4
0.0
0.0
0.0
0.0
Evaporative Emissions
g/km
2.2
2.2
2.2
1.9
1.9
0.3
g/mi
3.6
3.6
3.6
3.1
3.1
0.5
-------
LIGHT-DUTY, DIESEL-POWERED VEHICLES
Carbon monoxide, hydrocarbons, and nitrogen oxides emission factors for the
light-duty, diesel-powered vehicle are shown in Table A-16. These factors are based on
tests of several Mercedes 220D automobiles using a slightly modified version of the
Federal light-duty vehicle test procedure. Emissions from light-duty diesel vehicles
during a calendar year (n) and for a pollutant (p) were calculated using:
n
enp = cipn min
i=n-12
where: e = Composite emission factor in grams per vehicle mile for
calendar year (n) and pollutant (p)
c-n = The 1975 Federal test procedure emission rate for pollutant
iL
(p) in grams/mile for the i model year at calendar year
(n) (Table A-16).
m. = The fraction of total light-duty diesel vehicle miles driven
th
by the i model year diesel light-duty vehicles (Table A-
17).
HEAVY-DUTY, GASOLINE-POWERED VEHICLES
The composite exhaust emission factor was calculated using:
n
e = 2_ c. m. v.
nps *-' ipn in ips
i=n-12
where: e = Composite emission factor in g/mi (g/km) for calen
dar year (n), pollutant (p), and average speed (s)
A-22
-------
Table A-16. EMISSION FACTORS FOR LIGHT-DUTY, DIESEL-POWERED
VEHICLES.
Pollutant
Calendar
Model Year
1963
1964
1965
1966
1967
196S
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
Light-Duty Diesel Powered Vehicles
FTP Exhaust Emission Rates
CO
Yr.
1975
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1985
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1995
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
HC
1975
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
1985
0.5
0.5
0.5
0.5
0.5
-0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
1995
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
A-23
-------
Table A-17. FRACTION OF ANNUAL LIGHT-DUTY, DIESEL-POWERED
TRAVEL BY MODEL YEAR.
Age,
Years
1
2
3
4
5
6
7
8
9
10
11
12
> 13
Fraction of total
Vehicles in Use
(a)
.138
.084
.040
.074
.051
.064
.111
.131
.081
.034
.064
.024
.104
Average Annual
Miles Driven (b)
15,900
15,000
14,000
13,100
12,200
11,300
10,300
9,400
8,500
7,600
6,700
6,700
6,700
a x b
2,194.2
1,260.0
560.0
969.4
622.2
723.2
1,143.3
1,231.4
688.5
258.4
428.8
160.8
696.8
Fraction
of Annual
Travel (m= -^ )
.201
.115
.051
.089
.057
.066
.105
.113
.063
.024
.039
.015
.064
A-24
-------
c = The test procedure emission factor for pollutant (p) in g/rm
ipn th
(g/km) for the i model year in calendar year (n)
m. = The weighted annual travel of the i* model year vehicles
during calendar year (n). The determination of this
variable involves the use of the vehicle year distribution.
v = The speed correction factor for the i* model year vehicles
ips r
for pollutant (p) and average speed (s)
The projected test procedure emission factors (c- ) are summarized in Table A-18.
These projected factors are based on the San Antonio Road Route test and assume 100
percent warmed-up vehicle operation at an average speed of approximately 18 mph.
Table A-19 contains fraction of annual heavy-duty gasoline powered vehicle travel by
model year. Speed correction factor data are contained in Tables A-20 and A-21.
In addition to exhaust emission factors, the calculation of evaporative and
crankcase hydrocarbon emissions were determined using:
n
f
n
i=n-12
where: f = The combined evaporative and crankcase hydrocarbon
n
emission factor for calendar year (n)
h. = The combined evaporative and crankcase hydrocarbon
emission rate for the i* model year. Emission factors for
this source are reported in Table A-22.
m. = The weighted annual travel for the i model year vehicle
in
during calendar year (n)
A-25
-------
Table A-IS. CARBON MONOXIDE AND HYDROCARBON EXHAUST EMISSION
FACTORS FOR HEAVY-DUTY, GASOLINE-POWERED VEHICLES.
Pollutant
Calendar Y
Model Year
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
197*
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
Heavy Duty Gasoline Powered Vehicles
FTP Exhaust Emission Rates
CO
r.
1975
238.0
238.0
238.0
238.0
238.0
238.0
238.0
188.0
188.0
188.0
188.0
168.0
167.0
1985
188.0
176.0
176.0
176.0
175.0
124.0
123.0
122.0
121.0
120.0
119.0
118.0
117.0
t
1995
126.0
126.0
126.0
126.0
125.0
124.0
123.0
122.0
121.0
120.0
119.0
118.0
117.0
1975
35.4
35.4
35.4
35.4
35.4
35.4
35.4
14.1
14.0
13.9
13.8
J3.2
13.1
HC
1985
14.4
14.0
14.0
14.0
13.9
6.3
6.2
6.2
6.2
6.1
6.1
6.1
6.0
1995
j
6.3
6.3
6.2
6.2
6.2
6.2
6.2
6.2
6.1
6.1
6.1
6.0
6.0
A-26
-------
Table A-19. FRACTION OF ANNUAL HEAVY-DUTY, GASOLINE-POWERED
VEHICLE TRAVEL BY MODEL YEAR.
Age,
Years
1
2
3
*
. 5
6
7
8
9
10
11
12
> 13
Fraction of Total
Vehicles in Use
(a)
.059
.097
.110
.1*8
.063
.069
.071
.0*3
.0*2
.0*3
.033
.031
.191
Average Annual
Miles Driven (b)
19,000
18,000
17,000
16,000
1*,000
12,000
10,000
9,500
9,000
8,500
8,000
7,500
7,000
a x b
1,121.0
1,7*6.0
1,870.0
2,368.0
882.0
828.0
710.0
*08.5
378.0
365.5
26*. 0
232.5
1,337.0
Fraction
of Annual
Travel (m (axb) )
i ravel \m- z(axb) >
.090
.1*0
.1*9
.189
.071
.066
.057
.033
.030
.029
.021
.019
.106
A-27
-------
ro
oo
Table A-20. COEFFICIENTS FOR SPEED CORRECTION FACTORS FOR HEAVY-DUTY, GASOLINE-POWERED
VEHICLES.
Location
Low Altitude
Model
Year
Pre-1970
Post- 1969
(A + BS + CS2)
v = e
Hydrocarbons
A
0.953
1.070
B
-6.00 x 10"2
-6.63 x 10"2
C
5.81 x 10~*
5.98 x 10~*
Carbon Monoxide
A
0.967
1.0*7
B
-6.07 x 10"2
-6.52 x 10"2
C
5.78 x 10"*
6.01 x 10"*
Equations should not be extended beyond the range of the data (15 to 45 mph). For speed correction
factors at low speeds (5 and 10 mph) see Table A-21.
-------
Table A-21. LOW AVERAGE SPEED CORRECTION FACTORS FOR
HEAVY-DUTY, GASOLINE-POWERED VEHICLES.
Location
Low Altitude
Model
Year
Pre-1970
Post- 1969
Carbon Monoxide
5 mi/hr
(8 km/hr)
2.72
3.06
10 mi/hr
(16 km/hr)
1.57
1.75
Hydrocarbons
5 mi/hr
(8 km/hr)
2.50
2.96
10 mi/hr
(16 km/hr)
1.45
1.66
A-29
-------
Table A-22. CRANKCASE AND EVAPORATIVE HYDROCARBON EMISSION
FACTORS FOR HEAVY-DUTY, GASOLINE-POWERED VEHICLES.
Location
Low Altitude
Model
Years
Pre-1968
1968-1978
Post- 1978
Crankcase Emissions
g/mi
5.7
0.0
0.0
g/km
3.5
0.0
0.0
Evaporative Emissions
g/mi
5.8
5.8
2.9
g/km
3.6
3.6
1.8
A-30
-------
HEAVY-DUTY, DIESEL-POWERED VEHICLES
Emissions from heavy-duty, diesei-powered vehicles during a calendar year (n) and
for a pollutant (p) were calculated using:
n
enps = cipnminvips
i=n-12
where: e = Composite emission factor in g/mi (g/km) for calendar year
(n), pollutant (p), and average speed (s)
c. = The emission rate in g/mi (g/km) for the i model year
vehicles in calendar year (n) over a transient urban driving
schedule with average speed of approximately 18 mi/hr
m. = The fraction of total heavy-duty diesel miles (km) driven by
A.L
the i model year vehicles during calendar year (n)
v. = The speed correction factor for the i model year heavy-
IDj
duty diesel vehicles for pollutant (p) and average speed (s)
Values for c. are given in Table A-23; values for m. are in Table A-24. The speed
correction factor (v. ) was computed using data in Table A-25.
MOTORCYCLES
The composite exhaust emission factor was calculated using:
n
-
nps ~ ^ ipn in ips
where: e = Composite emission factor in g/mi (g/km) for calen-
dar year (n), pollutant (p), and average speed (s)
A-31
-------
Table A-23. CARBON MONOXIDE, HYDROCARBON EXHAUST EMISSION
FACTORS FOR HEAVY-DUTY, DIESEL-POWERED VEHICLES
BY CALENDAR YEAR.
Pollutant
Calendar Y
Model Year
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
197ft
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
Heavy-Duty Diesel Powered Vehicles
FTP Exhaust ^mission Rates
CO
r.
1975
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
1985
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
1995
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
28.7
HC
1975
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
1985
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
1995
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
A-32
-------
TABLE A-24. FRACTION OF ANNUAL HEAVY-DUTY DIESEL-POWERED
VEHICLE TRAVEL BY MODEL YEAR.
Age,
Years
1
2
3
. 4
5
6
7
g
9
10
11
12
> 13
Fraction of Total
Vehicles in Use
(a)
.058
.105
.153
.115
.095
.074
.075
.054
.057
.046
.030
.030
.107
Average Annual
Miles Driven (b)
70,000
70,000
70,000
70,000
62,000
50,000
46,000
43,000
42,000
30,000
25,000
25,000
25,000
a x b
4,060
7,350
10,710
8,050
5,890
3,700
3,450
2,322
2,394
1,380
750
750
2,675
Fraction
of Annual
Tr_vr, /_ (axb) }
Travel (m- z(axb))
.076
.137
.200
.151
.110
.069
.065
.043
.045
.026
.014
.014
.050
A-33
-------
Table A-25. EMISSION FACTORS FOR HEAVY-DUTY, DIESEL-POWERED
VEHICLES UNDER DIFFERENT OPERATING CONDITIONS
(g/min).
Pollutant
Carbon Monoxide
Hydrocarbons
Nitrogen Oxides
(NO as NO-)
Jv fc
Operating Mode
Idle
0.64
0.32
1.03
Urban
(18 mi/hr; 29 km/hr)
8.61
1.38
6.27
Over-the-road
(60 mi/hr; 97 km/hr)
5.40
2.25
28.3
For average speeds less than 18 mi/hr (29 km/hr), the correction factor
is:
i x
Urban + ( - 1) Idle
V
Urban
Where: S is the average speed of interest (in mi/hr), and the urban and
idle values (in g/min) are obtained from Table A-25. For average speeds
above 18 mi/hr (29 km/hr), the correction factor is:
18
v =
425 [(60-S) Urban + (S-18) Over the Road]
Urban
Where: S is the average speed (in mi/hr) of interest. Urban and over-
the-road values (in g/min) are obtained from Table A-25. Emission factors
for heavy-duty diesel vehicles assume all operation to be under warmed-
up vehicle conditions. Temperature correction factors, therefore, are not
included because ambient temperature has minimal effects on warmed-up
operation.
A-34
-------
c. = The test procedure emission factor for pollutant (p) in
lpn th
g/mi (g/km) for the i model year in calendar year
(n)
m. = The weighted annual travel of the i* model year
in
vehicles during calendar year (n). The determination
of this variable involved the use of the vehicle year
distribution.
v. = The speed correction factor for the i model year
vehicles for pollutant (p) and average speed (s)
The emission factor results of the Federal Test Procedure (c. ) as modified for
ipn
motorcycles are summarized in Table A-26. Table A-27 contains fraction of
annual travel by model year. Because there are no speed correction factor data
for motorcycles, the variable v. was assumed to equal one. The emission factor
for crankcase and evaporative hydrocarbons is presented in Table A-28.
A-35
-------
Table A-26.
CARBON MONOXIDE AND HYDROCARBON EXHAUST
EMISSION FACTORS FOR MOTORCYCLES FOR CALENDAR
YEAR 1975, 1985 AND 1995.
Pollutant
Calendar
Model Year
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
197*
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
Motorcycles
FTP Exhaust Emission Rates
CO
Yr.
1975
30.6
30.6
30.6
30.6
30.6
30.6
30.6
30.6
30.6
30.6
30.6
30.6
30.6
1985
30.6
30.6
30.6
30.6
30.6
30.6
30.6
30.6
30.6
30.6
30.6
29.4
3.4
1995
30.6
30.6
30.6
30.6
30.6
30.6
30.6
5.1
4.8
4.4
4.1
3.7
3.4
HC
1975
8.
8.
8.
8.
8.
8.
8.
8.
8.
S.
8.
8.1
8.1
1985
8.1
8.1
8.1
8.1
8.1
8,1
8.0
7.5
7.0
6.5
6.0
5.5
0.4
1995
8.1
8.1
8.1
8.1
8.1
8.1
8.0
0.8
0.7
0.6
0.6
0.5
0.4
A-36
-------
Table A-27. FRACTION OF ANNUAL MOTORCYCLE TRAVEL BY MODEL
YEAR.
Age,
Years
1
2
3
4
5
6
7
8
9
10
- 11
[ 12
> 13
Fraction of Total
Vehicles in Use
(a)
.112
.157
.171
.146
.123
.087
.051
.042
.029
.022
.016
.008
.037
Average Annual
Miles Driven (b)
2,500
2,100
1,800
1,600
1,400
1,200
1,100
1,000
950
900
850
800
800
a x b
280.0
329.7
307.8
233.6
172.2
104.4
56.1
42.0
29.6
19.8
13.6
6.4
29.6
Fraction
of Annual
Tr-wrl (m (axb) )
Travel (m- -z
-------
Table A-28. CRANKCASE AND EVAPORATIVE HYDROCARBON EMISSION
FACTORS FOR MOTORCYCLES.
Pollutant
Hydrocarbons
Crankcase
Evaporative0
Emissions
2 -Stroke Engine
g/mi
0.36
g/km
__
0.22
4 -Stroke Engine
g/mi
0.60
0.36
g/km
0.37
0.22
The motorcycle population was assumed to be 60 percent ^-stroke
and 4-0 percent 2-stroke when computing emission rates.
Most 2-stroke engines use crankcase induction and produce no crankcase
losses.
Evaporative emissions were calculated assuming that carburetor losses
were negligible. Diurnal breathing of the fuel tank (a function of fuel
vapor pressure, vapor space in the tank, and diurnal temperature varia-
tion) was assumed to account for all the evaporative losses associated
with motorcycles. The value presented is based on average vapor
pressure, vapor space, and temperature variation.
A-38
-------
REFERENCES
Department of Transportation. Special Area Analysis Program Package. 1973.
Trijonis, J.C. and K.W. Arledge. Utility of Reactivity Criteria in Organic
Emission Control Strategies for Los Angeles, TRW Report in fulfillment of
EPA Contract No. 68-02-1735. 1975.
U.S. Environmental Protection Agency. Compilation of Air Pollution Emission
Factors. Report AP^2, Second edition with supplements. 1976.
A-39
-------
APPENDIX B
Traffic Emission Projections to 1980, 1990 and 2000
-------
This appendix gives details of traffic emission projections for the years 1980,
1990, and 2000 given emissions for the years 1975, 1985, and 1995 (see Sections IV and
VI and Appendix A of this report). Vehicle miles travelled (VMT) and emission factors
for each vehicle class for the years 1980, 1990, and 2000 were obtained. Emissions were
then computed using the equation:
E=Z (VMT). (EF).
* 1
where: E = Total traffic emissions
(VMT). = Total vehicle miles traveled for vehicle class i
(EF). = Emission factor for vehicle class i at the average speed.
VMT for each vehicle class and both facility types (freeway and arterial) for 1975,
1985 and 1995 were obtained from traffic data supplied by the Transportation and
Planning Office of the Maricopa Association of Governments (MAG-TPO). Linear
interpolation and extrapolation were applied to this data to get VMT for 1980, 1990, and
2000. These VMT's are shown graphically in Figure B-l.
To compute emission factors for the years 1980, 1990, and 2000, average speeds
for the years 1975, 1985, and 1995 were extracted for each vehicle class and facility
type by relating emissions to VMT. These speeds were then interpolated for 1980, 1990,
and 2000 and are shown in Table B-l. Emission factors were computed using AP-42
(EPA, 1976) using these speeds and are presented on Tables B-2 and B-3. Secondary
traffic was again assumed to have 14% of primary traffic VMT with an average speed of
20 mph and the following vehicle mix: 80.04% light-duty gas vehicles, 19.92% light-
duty trucks, and 0.04% light-duty diesel vehicles. Emissions for 1980, 1990, and 2000
were then obtained by using the emission factors and VMT for those years. Projected
traffic emissions for 1980, 1990, and 2000 by vehicle type are presented in Table B-4.
Figure B-2 presents traffic emission trends through 2000.
B-l
-------
1975
1980
1985 1990
YEARS
1995
2000
Figure B-l .Projected vehicle miles traveled by facility type.
B-2
-------
Table B-l. AVERAGE VEHICLE SPEEDS BY VEHICLE CLASS
AND FACILITY TYPE, (mph)
Facility
Type
Freeway
Arterial
Freeway
Arterial
Freeway
Arterial
Freeway
Arterial
Freeway
Arterial
Freeway
Arterial
Year
1975
1980
1985
1990
1995
2000
LDV1
42
2k
42
28
42
32
42
33
43
34
42
33
LOT2
42
24
41
27
40
30
39
29
37
29
39
29
HDV2
42
24
40
27
39
29
38
29
38
29
38
29
HDD4
43
26
41
28
40
29
39
30
39
30
39
30
1
2
3
LDV: Light-duty gasoline vehicle
LOT: Light-duty gasoline truck
HDV: Heavy duty gasoline vehicle
HDD: Heavy duty diesel vehicle
B-3
-------
Table B-2. CO EMISSION FACTORS DERIVED FROM AVERAGE SPEEDS.
(g/mi)
Year
1980
1990
2000
^XVehicle
FuncXClass
ClassX.
3
Secondary
Arterial
Freeway
Secondary
Arterial
Freeway
Secondary
Arterial
Freeway
LDV
27.65
19. 40
12.63
4.85
2.78
2.13
4.85
2.68
2.08
LOT
39.54
29.01
18.74
14.42
9.58
6.83
14.42
9.58
7.25
HDV
_ _
122.96
89.60
--
86.28
68.97
--
86.28
68.97
LDD1
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
HDD
_ _
16.90
10.00
--
15.50
10.91
--
15.50
10.91
MC2
29.91
29.91
7.26
7.26
7.26
7.26
1
2
3
LDD: Light duty diesel vehicle
MC: Motorcycle
Secondary traffic was assumed to have the following vehicle mix:
80.04% LDV, 19.92% LOT, and 0.04% LDD
B-4
-------
Table B-3. NMHC EMISSION FACTORS DERIVED FROM AVERAGE SPEEDS.
(g/mi)
Year
1980
1990
2000
^^^ehicle
^XClass
Funct.^^^
Class ^x,
Secondary
Arterial
Freeway
Secondary
Arterial
Freeway
Secondary
Arterial
Freeway
LDV
4.34
3.74
3.24
1.08
.92
.88
.98
.82
.78
LOT
6.95
6.10
5.26
2.50
2.09
1.86
2.16
1.75
1.55
HDV
ğ
13.81
11.28
__
6.35
5.69
--
6.69
5.97
LDD
.41
.41
.41
.41
.41
.41
.41
.41
.41
HDD
__
3.06
2.44
--
2.97
2.52
2.97
2.52
MC
-
6.49
6.49
--
2.04
2.04
--
2.04
2.04
B-5
-------
Table B-4. PROJECTED TRAFFIC EMISSIONS BY VEHICLE TYPE.
(tons/day)
Category
1. Primary Traffic
a. Light duty gas vehicle
b. Light duty gas truck
c. Heavy duty gas truck
d. Light duty diesel vehicle
e. Heavy duty diesel vehicle
f. Motorcycle
Subtotal
2. Secondary traffic
Total traffic
1980
CO
293.6
109.1
132.1
<0.1
4.6
4.0
543.4
91.7
635.1
NMHC
59.4
22.0
15.2
<0.1
0.9
0.9
98.4
14.9
114.3
1990
CO
59.8
50.3
135.2
<0.1
6.2
1.4
252.9
29.6
282.5
NMHC
21.1
11.7
10.4
<0.1
1.2
0.4
44.8
6.0
50.8
2000
CO
74.4
65.6
177.9
<0.1
8.1
1.8
327.8
38.9
366.7
NMHC
24.6
12.7
14.5
<0.1
1.7
0.5
54.0
7.0
61.0
-------
12OO
1
p
200
1OO
1975
1980
1985 1990
YEARS
1995
2OOO
Figure B-2.Traffic emissions trend through 2000.
B-7
-------
REFERENCES
U.S. Environmental Protection Agency. Compilation of Air Pollution Emission
Factors. Report AP42, Second edition with supplements. 1976.
B-8
-------
APPENDIX C
Non-Traffic Emissions
Base Year (1975)
-------
This appendix presents details of non-traffic emission computation for the base
year (1975). It consists of the pertinent parts of "Emission Inventory Report for the
Phoenix Study Area," (Pacific Environmental Services, 1976).
A summary table is presented in Table C-l.
I. BACKGROUND
The baseline document for the emissions inventory is the National Emissions Data
System (NEDS) Summary, run date of January 27, 1976. (Ref. 1) Despite the date of
the Summary, it actually represents emissions data from the year 1972. Since the year
of record for the emissions inventory is 1975, the first step required was to update the
status of entries in various categories of emission sources.
Maricopa Association of Governments (MAG) loaned PES the master copy of the
recently updated 1975 land use map. PES had the map photographed in color, and had
20" x 24" color prints made for gridding and determination of land uses over the entire
study area.
II. EMISSION SOURCES
ELIMINATION OF SOURCES
As a result of ordinances passed in 1971, there is no longer any open burning in the
Phoenix area. Incineration is conducted within the commercial and industrial areas, but
there is no residential incineration. The 1975 emission summary now reflects the
deletion of emissions resulting from the above action.
1972-1975 GROWTH
Conversations with Mr. Charles Mann, National Aerometric Data Bank, Research
Triangle Park, North Carolina and with Mr. Witherspoon of the Maricopa County
Department of Public Health also confirmed the fact that the January 27, 1976 NEDS
Summary reflects emissions data from calendar 1972. Maricopa County indicated that
C-l
-------
Table C-l. SUMMARY TABLE.
1975 TOTAL EMISSIONS FOR PHOENIX AREA
(short tons/year)
Category
1. Point Sources
2. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
3 . Airports
4 . Railroads
TOTAL
CO
265
233
385
1,745
361
9,901
1,112
14,002
THC
4,925
93
166
767
18,133
1,076
804
25,964
NMHC
4,916
0
96
502
18,133
1,073
788
25,508
C-2
-------
updated emissions information for 1973, 197*, or 1975 had not been and would not be
made avialable at this time but that reestimates of these emissions based on population
increases from 1972 to 1975 would be realistic.
PES has therefore made reestimates of some of the categories of emissions in the
January 1976 NEDS Summary as follows:
1. According to DES (Department of Economic Security - official estimator for
Arizona) (Reference 2, page 78), the population of Maricopa County for 1972
was 1,069,750 and for 1975 was 1,230,000 or a gain of 15 percent for those
three years. Population within the planning area is approximately 98
percent of Maricopa County. To obtain area emissions for the study area for
1975, the NEDS Summary totals were increased by 14.7 percent (15 x .98)
for the following emission categories:
a. Fuel combustion
1. Residential
2. Industrial
3. Commercial/Institutional
b. On-site incineration
1. Commercial/Institutional
2. Industrial
c. Solvent evaporation loss
2. Electrical power generation
a. Comparison of power generated in 1972 and 1975. FPC form Is for
four major electric generating plants in Phoenix indicated that the
total power generated in 1975 = 1.925 x 106 MWHR and total power
generated in 1972 = 4.090 x 106 MWHR for a net decrease of 2.165 x
106 MWHR or 53 percent.
C-3
-------
This decrease of electrical power generated in the study area is caused
primarily by the increasing trend to have base power load supplied by
the generating stations at Navajo, Cholla, and Santan,with Ocotillo,
Agua Fria and Kyrene supplying peak loads. This downward trend is
expected to continue over the next twenty years.
b. Fuel for power generation. Another feature which effected the change
in emissions for power generation between 1972 and 1975 was the
percentage of fuel oil and natural gas used for each of those two years.
Data obtained from FPC, and verified by both the Arizona Public
Service and Salt River Project plants indicated that the use of natural
gas had decreased by a factor of almost six, while the use of fuel oil
had increased by a factor of more than four.
3. Miscellaneous area-wide sources
a. Gasoline handling evaporation losses. Normally the 1972 emissions for
this category would have been increased by the same percentage as the
population growth to obtain 1975 emissions. In view of the energy
crises of 1973 and 1974 however, the consumption in 1975 was
estimated at 104 percent of the 1972 figure.
b. Solvent evaporation and structural fires. 1972 emissions were
increased by 14.7 percent (population increase). Emissions caused by
frost control measures were deleted since the majority of those would
be emitted outside the study area.
4. Aircraft emissions
Baseline emissions from NEDS, 1976, were not employed since more
accurate and precise information was obtained from other sources.
a. Military aircraft. Luke Air Force Base on the Western extremity of
the study area and Williams Air Force Base in the Southeast corner are
the only two airports accommodating significant military aircraft
C-4
-------
operations in this area, although some military aircraft operations are
included under Sky Harbor International Airport operations. Informa-
tion on landing and takeoff cycles, touchdowns, type and number of
aircraft, airport areas, hours and days of operation and emission
factors were obtained from References 3 through 6.
b. Commercial aircraft. All major airlines using commercial aircraft
operate out of Sky Harbor International Airport. Although some data
was obtained from FAA sources, the final selection of data utilized of
this report was taken from References 7, 8 and 9.
c. Civil aircraft. There are eight airports (including Sky Harbor) in the
study area which handle sufficient numbers of civil aircraft to be
included in the report. The key reference employed was Reference 7,
with supporting information obtained from References 10, 11, and 12.
The mix of civil aircraft types registered at Sky Harbor Airport was
obtained from Reference 7, "Final Environmental Impact Statement
for Phoenix Sky Harbor International Airport Improvement Program
August 1974." This document also contained emissions per landing/
takeoff cycle (LTO) and frequency of civil aircraft operations. The
emissions for a composite civil aircraft were calculated as explained in
Section III; that same value was applied to the known aircraft
operations for 1975 at the other seven (7) civil airports. Although the
exact airport land areas were available, the airport areas as read from
MAG's 1975 land use map were employed in determining emissions to
the appropriate grid and still maintain the integrity of the land use
patterns shown on the MAG map. (See also Table C-2).
5. Railroads
The total emissions from railroads in Maricopa County were obtained from
Reference 1, updated by a 4 percent growth factor for 1975 (one-half of the
Arizona Statement Implementation Plan for growth of 8 percent between
1969 and 1975). Total length of rail lines in Maricopa County for Southern
Pacific and Santa Fe railroads were obtained from the district traffic
C-5
-------
Table C-2. CIVIL AIRPORT FACILITIES- PHOENIX AREA.
Name
Chandler Municipal
Deer Valley
Falcon Field-Mesa
Glendale Municipal
Phoenix-Litchfield
Scottsdale Municipal
Sky Harbor (Civil Air-
craft Operations Only)
Stellar City Air Park
TOTALS
1975 :
Aircraft
Registered
5<
15b
325*
300
330*
222b
123b
103*
9*b
96°
126?
202b
600a
600
70b
1628e
Total Aircraft
Movements
60,000*
* 12.000*
135,000*
275,000°
166,246C
275,000*
* 175,000°
20,000;J
* lOOjOOO0'0
125,000*
80,000°
122,000°
60,000*
* 150, 000°'°
264,OOQa
322, ^33C
* 60,000°
l,107,679e
Notes:
FAA Reports 5010-1
Landrum and Brown Reports
Sky Harbor Airport Reports
Airport Manager Estimates
PES Estimates
a.
b.
c.
d.
e.
* Using estimate of 844 movements per aircraft from Landrum and Brown.
Underlined figures indicate those selected by PES from sources available and used i
calculations in Section III.
C-6
-------
offices of those two railroads for both through lines and support or switching
lines. U.S.G.S. maps for the Phoenix area, railroad yard maps and railroad
computer readouts were employed to compute the total rail lines in each
grid. Discussion with traffic control representatives from both railroads
indicated that it was realistic to allocate the same emission factor for both
through lines and switching lines.
6. Point sources
A total of thirty-nine (39) point sources with THC and/or CO emissions were
obtained from the NEDS Point Source Listing for Arizona, by county, (NEDS
FORM 4) dated November 14, 1975. (Reference 13). Despite the date of
this report, the data represent 1972 emissions. In updating these emissions
to 1975, four sources were deleted completely due to discontinuance of
operation and four (all power plants) required complete recalculation of
emissions based upon FPC and power plant reports for 1975 and using
emissions factors in AP42. (Reference
Emissions in kg/hr were computed for 250 days/year (except as noted for
individual sources), based upon the production work schedule for 1975
obtained via telephone conversation with each soruce. Discussions with Mr.
Gregg Witherspoon indicated that it would be realistic to assume no increase
in process emissions between 1972 and 1975.
7. Computations for airport emissions
Emissions for THC and CO were first obtained in tons/year for the individual
airport. Airport areas were read from the 1975 land use map and differed in
almost each case from the total airport areas as obtained from FAA, Sky
Harbor Authority or Military Base Reports.
C-7
-------
III. STATISTICAL DATA AND COMPUTATIONS FOR PHOENIX AREA
EMISSIONS INVENTORY, 1975
A. STATISTICAL DATA
Tons/year
THC
CO
1. Residential
Fuel Combustion
Area - Low Density 199.67
- High Density 13.44
(Sq. Miles) TOTAL 213.11
93 233
Low Density Factor = 1
High Density Factor = 4
Total Residential Equivalent
Units = 253.4
2. Commercial/Institutional
Fuel Combustion
Incineration
TOTAL
Area = 52.95 Sq. Miles
TOTAL
83
83
166
196
189
385
3. Industrial
Fuel Combustion
Incineration
25
742
38
1707
767
1745
Area = 20.63 Sq. Miles
4. Area Wide Sources
(Miscellaneous)
Gas Handling
Solvent Evaporation and
Structural Fires
TOTAL
Area = 306.4 Sq. Miles
7000
361
361
C-8
-------
Tons/year
Railroads
Total Miles in Maricopa County = 385
(Total Miles in Phoenix Study Area =
Aircraft
a. Sky Harbor Airport
Commercial
Civil
Military
TOTAL
b. Civil Airports
Chandler Municipal
Deer Valley
Falcon Field-Mesa
Glendale Municipal
Phoenix - Litchf ield
Scottsdale Municipal
Stellar City Air Park
c. Military Airports
Luke AFB
Williams AFB
i
Airport Areas
Sky Harbor
Civil Airports
THC
1458
miles
212 Miles)
168
18
35.3
221.3
.7
9.2
9.7
5.6
6.8
8.3
3.3
360
451
1975 Land
Use Map
1.883
3.115
CO
2017
404
1009
250
1663
37.6
520
548
313
382
470
188
3014
2765
Sq. Miles
FAA Reports
5010-1
3.125
4.27
C-9
-------
7. Airport Areas (cont'd)
Luke AFB
Williams AFB
TOTAL
0.875
2.406
8.279
6.53
5.78
19.71*
8. Total Areas
Residential
Commercial/Institutional
Industrial
Airports
TOTAL
Sq. Miles
213.11
52.95
20.63
19.71
306.74
B. COMPUTATIONS OF ANNUAL EMISSION FACTORS PER SQUARE MILE
Annual emission factors per sq. mile are obtained by dividing the annual emissions
by the emission area in sq. miles
Category
Residential -
Low Density
THC
93
253.4
CO
233 tons/yr.
253.4 sq. miles
= 0.367
= 0.919 tons/yr/sq. mile
Residential --
High Density
Low Residential x
= 1.468
= 3.676 tons/yr/sq. milt
Commercial/
Institutional
166
52.95
= 3.135
385 tons/yr.
52.95 sq. miles
= 7.271 tons/yr/sq. mil<
19.71 square miles of airport area used to compute total land use areas for miscellan-
eous emissions.
C-10
-------
Industrial
767
20.63
tons/yr
20.6 5 sq. miles
= 37.179
= 8*.585 tons/yr/sq. mile
Miscellaneous
18133
306.*
36 i tons/yr
306.4 sq. miles
= 59.181
= 1.178 tons/yr/sq. mile
Railroads
1458
2017 tons/yr
385 miles
= 3.787
= 5.239 tons/yr/mile
c-n
-------
C. 1975 DISTRIBUTION OF THC INTO METHANE AND NON-METHANE PERCENT-
AGE (REF. 16 used for estimate of %).
CH %
NMHC%
Residential
Fuel Combustion
Commercial/Institutional
Fuel Combustion
Incineration
Industrial
Fuel Combustion
Incineration
Area Wide Source
(Miscellaneous)
100% 0%
50% 50%
34% 66%
50% 50%
34% 66%
Gas Handling
Solvent Evaporation
& Structural Fires
100%
100%
Railroads
(212 out of 385 miles)
2%
98%
Aircraft
Jet (Commercial & Military)
Piston (Civil Aircraft)
0%
5%
100%
95%
Power Plant
Gas
Oil
100%
5%
0%
95%
C-12
-------
D. ELECTRIC GENERATING PLANTS - PHOENIX 1972 AND 1975
Plant/Year
Agua Fria
1972
1975
Crosscut
1972
1975
Kyrene
1972
1975
Ocotillo
1972
1975
West Phoenix*
1972
1975
Totals
1972
1975
Net Power
Generated
KWHR x 106
2272
1031
8
415
16*
1282
626
113
104
4090
1925
Fuel Used
Gas
MCF x 103
18860
2806
138
4630
844
12011
2465
1376
578
37015
6693
Oil
BBL x 103
380
1381
1.2
86
231
116.5
779
17.7
143
601.4
2534
Emissions
Tons/Yr.
CO
184
111
1.2
--
44.8
21.7
109
70
12.8
13.9
352
217
THC
25.4
59.4
0
-
5.9
10.1
10.9
33.9
1.4
6.3
44
110
West Phoenix Plant was dosed in the mid 1960's; then reactivated in 1969 for
partial operation. It has been used to supply peak load demands especially during
the summer. APS spokesmen indicated this plant will have been phased out by
1995.
C-13
-------
REFERENCES
1. National Emissions Data Systems (NEDS) Summary Report for Maricopa County,
run date January 27, 1976.
2. Maricopa Association of Governments report, "An air quality evaluation of the
1980 Transportation Improvement Program and the 1995 Transportation Plan
for the Phoenix region," dated May 1, 1975.
3. Luke Air Force Base, Arizona report titled, "Air installation compatible use zone,"
March 1976.
4 . Draft environmental statement on the F-15 Beddown at Luke Air Force Base,
Arizona. AF-ES-74-3D, April 1974.
5. Telephone conversations with Major Lake, Williams Air Force Base, during May
and 3une 1976.
6. U.S.A.F. air pollutant emission factors for landing and takeoff cycles. AFWL-TR-
74-303, February 1975 and advance changes thereto.
7. Final environmental impact statement for Phoenix Sky Harbor International
Airport Improvement Program, August 1974.
8. City of Phoenix Aviation Department activity reports for specific months in 1974,
1975 and 1976.
9. Sky Harbor International Airport activity reports for specific periods in 1975 and
1976.
10. General aviation airport area evaluation, Phoenix, Arizona. Prepared for the City
of Phoenix Aviation Department by Landrum and Brown, February 1976.
11. Site evaluation, Goodyear Airfield, Phoenix, Arizona. Prepared for the City of
Phoenix Aviation Department by Landrum and Brown, September 1975.
12. FAA airport master record (form 5010) for eight municipal airports in the Phoenix
area.
13. NEDS point source listing for Arizona, by County (NEDS Form 4), dated November
14, 1975.
14. U.S. Environmental Protection Agency. Compilation of air pollutant emission
factors, AP-42.
15. General Research Corporation project, "Air quality impact of electric cars in Los
Angeles: Appendix A - Pollutant emissions estimates and projections for the
south coast air basin," August 1974.
16. Utility of reactivity criteria in organic emission control strategies for Los
Angeles. Prepared by TRW for EPA research Triangle Park, North Carolina,
December 1975.
17. Pacific Environmental Services, Inc. Emission Inventory Report for the
Phoenix Study Area, 1975-1995. 1976.
C-14
-------
APPENDIX D
Non-Traffic Emission Projections
-------
This appendix gives details of non-traffic emission computations for the years
1980, 1985, 1990, 1995, and 2000.
PES (1976) presented emissions for 1995 based on a 1.9 million population level.
Growth rates and emission factors were adjusted to reflect a 2.2 million population
level for that year, 1.7 million in 1985, and a linear change in between. Growth rates
refer to the rate of increased/decreased use of the source, while emission factors
reflect the effect of emission controls and energy conservation measures which will
generally be in full effect by 1995. Table D-l presents growth rates and emission
factors for all years for the various non-traffic emission sources.
For residential area sources (fuel combustion for space heating, etc.), a growth
factor of 2.123 was selected for 1995 to reflect the increased residential area (Maricopa
Association of Governments Composite Land Use Map for Maricopa County). The
emission factor adjustment reflects such tilings as electronic pilot lights and increased
use of solar energy. Commercial/Institutional growth rates and emission factors were
selected similarly.
The industrial growth rate was again based on area usage while emission factor
adjustment was used to reflect a trend toward light industry and the population increase
not accounted for by area increase.
Miscellaneous emissions are of three types: gasoline handling, solvent evaporation,
and structural fires. Growth rates reflect population increase while emission factors
are 1 for gasoline handling and structural fires and 0.3 for solvent evaporation,
reflecting the increased use of non-polluting solvents.
The growth rate for railroads was that suggested in the State of Arizona Air
Pollution Control Implementation Plan (Arizona State Department of Health, 1972).
Emission factor adjustments were made to reflect population increases not taken into
account by these growth rates.
For power generation, no new plants were anticipated. In addition, the trend in
the Phoenix area is for electric power generation to take place outside the area.
Therefore, a growth factor adjustment was made to reflect this.
D-l
-------
Table D-l. GROWTH AND EMISSION FACTORS FOR NON-TRAFFIC SOURCES
^*-^-^Year
Source ^"""^-^^^
Residential
Commercial /Institutional
a) Fuel Combustion
b) Incineration
Industrial
a) Fuel Combustion
b) Incineration
Miscellaneous
a) Gas Handling
b) Solvent Evaporation
c) Structural Fires
Railroads
Power Generators
Other Point Sources
1980
G.F.1
1.281
1.213
1.213
1.503
1.503
1.191
1.191
1.191
1.061
0.95
1.00
E.F.2
0.95
0.98
1.00
0.90
0.80
1.00
0.75
1.00
1.00
1.00
1.00
1985
G.F.
1.561
1.426
1.426
2.005
2.005
1.382
1.382
1.382
1.127
0.90
1.00
E.F.
0.89
0.95
1.00
0.80
0.60
1.00
0.50
1.00
1.00
1.00
1.00
1990
G.F.
1.842
1.639
1.639
2.508
2.508
1.586
1.586
1.586
1.196
0.85
1.00
E.F.
0.84
0.90
0.93
0.83
0.65
1.00
0.30
1.00
1.04
1.00
1.00
1995
G.F.
2.123
1.851
1.851
3.009
3 009
1.789
1.789
1.789
1.270
0.80
1.00
E.F.
0.80
0.85
0.85
0.85
0.70
1.00
0.10
1.00
1.079
1.00
1.00
2000
G.F.
2.404
2.064
2.064
3.512
3.512
1.993
1.993
1.993
1.347
0.80
1.00
E.F.
0.80
0.85
0.85
0.90
0.80
1.00
0.10
1.00
1.119
1.00
1.00
9
tsJ
1
2
G.F. = Growth Factor
E.F. = Emission Factor
-------
Other point sources were assumed to remain constant.
Sky Harbor International Airport emissions in 1995 at the 1.9 million population
level (PES, 1976) were adjusted to reflect the 2.2 million population level. Emissions
were not much changed from the 1985 level due to a lack of LTO cycle information
after 1985.
Civil aircraft emissions for 1995, population 1.9 million, were included in PES
(1976). These were adjusted to reflect the 1995 2.2 million population level. 1985
emissions were scaled to reflect the 1985/1995 total aircraft operation ratio.
Intermediate years were interpolated and 2000 was extrapolated.
Military aircraft operation emissions were assumed constant through 2000 based
on discussions with Air Force personnel.
Table D-2 presents projected emissions for non-traffic sources broken down by
source type.
D-3
-------
Table D-2. PROJECTED NON-TRAFFIC EMISSIONS
(tons/day)
" -^^Year
Category "-^^^^
Point Sources
Area Sources
a) Residential
b) Comm/Inst.
c) Industrial
d) Miscellaneous
Airports
Railroads
TOTAL
1980
CO
0.67
0.78
1.27
5.76
1.18
27.90
3.23
40.79
NMHC
13.49
0
0.32
1.66
50.09
3.00
2.29
70.85
1985
CO
0.66
0.89
1.47
5.79
1.37
28.65
3.43
42.26
NMHC
13.46
0
0.37
1.67
47.58
3.07
2.43
68.58
1990
CO
0.64
0.99
1.58
7.84
1.57
32.30
3.79
48.71
NMHC
13.47
0
0.40
2.25
44.93
3.21
2.68
66.94
1995
CO
0.61
1.08
1.66
10.12
1.77
36.09
4.18
55.51
NMHC
13.43
0
0.42
2.92
39.77
3.36
2.96
62.86
2000
CO
0.61
1.23
1.85
13.47
1.97
39.70
4.59
63.42
NMHC
13.44
0
0.46
3.88
44.30
3.50
3.25
68.83
a
-------
REFERENCES
Arizona State Department of Health, "The State of Arizona Air Pollution Control
Implementation Plan," May 1972.
Maricopa Association of Governments, Composite Land Use Map for Maricopa
County, 1976.
Pacific Environmental Services, Inc., "Emission Inventory Report for the Phoenix Study
Area 1975-1995", August
D-5
-------
APPENDIX E
Effect of Control Strategies
-------
This appendix presents details of the effects of control strategies on study area
emissions.
CONTROL STRATEGY EFFECTIVENESS DATA
Source: AQMA Task Force
The following maximum percent reductions in CO and HC emissions may be attri-
buted to each of the following control strategies selected by the AQMA Task Force.
(1) Inspection/Maintenance Program Decrease
CO HC
All light duty vehicle emissions (including motorcycles) 22% 37%
All heavy duty vehicle emissions 11% 7%
Source: ASDH, "Transportation Control Strategies," September 1973 and recent
Bureau of Vehicular Emissions Inspection revisions.
Inspection results for the first three months of the 1977 I/M program in Phoenix
show a failure rate of 16.8% corresponding to these reductions.
(2) Periodic Maintenance Decrease
CO HC
All light and heavy duty vehicle emissions
(assuming average mileage/registered vehicle
in Maricopa County = 7800) 35%
Source: Evaluation Report of Clean Air Research Company for California Air
Resources Board - Contract #ARB-65*.
E-l
-------
(3) Vapor Recovery Decrease
For 1985: HC
Phase I - Total Gasoline Vapor Emissions 36%
For 1995:
Phase I and II - Total Gasoline Vapor Emissions 81%
Maricopa County has estimated that 1975 gasoline vapor emissions from gasoline
stations and distribution points =18 tons/day.
Source: Maricopa County, "An Investigation into the Feasibility of Reducing
Hydrocarbon Emissions from Gasoline Evaporation Sources in Maricopa
County," September 1976.
(4) Dealer Emissions Guarantee
Supports stated effectiveness of I/M or Periodic Maintenance Program.
(5) Clean Air Rebate
Supports stated effectiveness of I/M or Periodic Maintenance Program.
(6) Carpooling
The 1985 and 1995 MAG assignments used to develop the AVSUP5 mobile source
emissions inventories assume 1970 auto occupancy levels. Increasing car
occupancy from 1.33 in 1970 to 1.* in 1985 and 1.5 in 1995 has the following
impact on mobile source emissions:
Decrease
CO HC Vehicle
Running Emissions Trips
1985 1.7M (1.* vs. 1.33) 5% 5% 5%
1995 2.2M (1.5 vs. 1.33) 12% 11% 11%
E-2
-------
Source: MAG Sketch Planning Models
(7)
Bicycle Systems
No reduction by 1985
CO
Running
Decrease
HC
Emissions
Vehicle
Trips
1995 2.2M
.6%
.6%
2.3%
Source: San Diego Air Quality Planning Report, "Transportation Management
Tactics for Air Quality Improvement," April 1976.
(8) Work and Driving Schedule Shifts
Changes in freeway and arterial % ADTs are as follows for 1985 and 1995:
Hour
6
7
8
15
16
17
Freeway %
7.2
7.2
7.2
8.*
8.3
8.3
Arterial %
5.9
5.9
5.9
8.2
8.2
8.1
The above percentages represent a flattening out of a.m. and p.m. peak
periods to represent staggered work hours.
The following tables present breakdowns of CO and NMHC emissions under the
proposed control strategies for 1980, 1985, 1990, 1995, and 2000. Also included are
breakdowns of the "no control" case which actually include traffic system improve-
ments, improved mass transit, and regional development planning. Breakdowns for
clean air rebate and dealer emission guarantees are not included because no reduction
over no control is forecast since these strategies are designed to support the inspection/
E-3
-------
maintenance or periodic maintenance programs and would, by themselves, be ineffec-
tive in bringing down vehicle emissions. Breakdowns for bicycle systems are not
included for 1980 and 1985 since no reduction is expected until 1990, while breakdowns
for work and driving schedule shifts are presented only for 1985 and 1995 because
detailed traffic data is not available for the other years of interest.
-------
Table E-1. EMISSIONS BREAKDOWN FOR THE BASE CASE IN 1980.
Category
1 . Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f. Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4 . Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
293.6
109.1
132.1
< 0.1
4.6
4.0
543.4
91.7
635.1
0.7
0.8
1.3
5.8
1.2
27.9
3.2
40.9
676.0
NMHC
tons/day
59.4
22.0
15.2
<0.1
0.9
0.9
98.4
14.9
114.3
13.5
0.3
1.7
50.1
3.0
2.3
70.9
185.2
E-5
-------
Table E-2. EMISSIONS BREAKDOWN FOR THE INSPECTION/MAINTENANCE
CONTROL STRATEGY IN 1980.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
i. Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c. Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
229.0
85.1
117.6
< 0.1
4.1
3.1
438.9
71.5
510.4
0.7
0.8
1.3
5.8
1.2
27.9
3.2
40.9
551.3
NMHC
tons/day
37.it
13.9
14.1
< 0.1
0.8
0.6
66.8
9.4
76.2
13.5
0.3
1.7
50.1
3.0
2.3
70.9
147.1
E-6
-------
Table E-3. EMISSIONS BREAKDOWN FOR THE PERIODIC MAINTENANCE
CONTROL STRATEGY IN 1980.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
CO
tons/day
190.8
70.9
85.9
< 0.1
3.0
2.6
353.2
59.6
412.8
0.7
0.8
1.3
5.8
1.2
27.9
3.2
40.9
NMHC
tons/day
39.2
14.5
10.0
< 0.1
0.6
0.6
64.9
9.8
74.7
13.5
--
0.3
1.7
50.1
3.0
2.3
70.9
TOTAL
453.7
145.6
E-7
-------
Table E-4. EMISSIONS BREAKDOWN FOR THE VAPOR RECOVERY CONTROL
STRATEGY IN 1980.
Category
1 . Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f. Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c. Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
293.6
109.1
132.1
< 0.1
4.6
4.0
543.4
91.7
635.1
0.7
0.8
1.3
5.8
1.2
27.9
3.2
40.9
676.0
NMHC
tons/day
59.4
22.0
15.2
< 0.1
0.9
0.9
98.4
14.9
114.3
13.5
0.3
1.7
46.0
3.0
2.3
66.8
181.1
E-8
-------
Table E-5. EMISSIONS BREAKDOWN FOR THE CARPOOLING STRATEGY
IN 1980.
Category
1 . Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4 . Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
284.8
105.8
132.1
< 0.1
4.6
4.0
531.3
88.9
620.2
0.7
0.8
1.3
5.8
1.2
27.9
3-2
40.9
661.1
NMHC
tons/day
57.6
21.3
15.2
< 0.1
0.9
0.9
95.9
14.5
110.4
13.5
--
0.3
1.7
50.1
3.0
2.3
70.9
181.3
E-9
-------
Table E-6. EMISSIONS BREAKDOWN FOR THE BASE CASE IN 1985.
Category
1 . Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f. Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c. Industrial
d. Miscellaneous
5. Airports
6. Railroads
TOTAL NON-TRAFFIC
CO
tons/day
116.3
67.1
123.7
< 0.1
5.3
4.2
316.6
47.6
364.2
0.7
0.9
1.5
5.8
1.4
28.7
3.4
42.3
NMHC
tons/day
32.8
15.1
11.4
< 0.1
1.1
0.9
61.2
9.2
70.4
13.5
--
0.4
1.7
47.6
3.1
2.4
68.7
TOTAL
406.5
139.1
E-10
-------
Table E-7. EMISSIONS BREAKDOWN FOR THE INSPECTION/MAINTENANCE
STRATEGY IN 1985.
Category
1 . Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
90.7
52.3
110.1
< 0.1
4.7
3.2
261.1
37.1
298.2
0.7
0.9
1.5
5.8
1.*
28.7
3.4
42.3
340.5
NMHC
tons/day
20.7
9.5
10.6
< 0.1
1.0
0.6
42.4
5.8
48.2
13.5
--
0.4
1.7
47.6
3.1
2.4
68.7
116.9
E-ll
-------
Table E-8. EMISSIONS BREAKDOWN FOR THE PERIODIC MAINTENANCE
STRATEGY IN 1985.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5 . Airports,
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
75.6
43.6
80.4
< 0.1
3.5
2.7
205.7
30.9
236.7
0.7
0.9
1.5
5.8
1.4
28.7
3.4
42.3
279.0
NMHC
tons/day
21.6
10.0
7.5
< 0.1
0.7
0.6
40.4
6.1
46.5
13.5
,_
0.4
1.7
47.6
3.1
2.4
68.7
115.2
E-12
-------
Table E-9. EMISSIONS BREAKDOWN FOR THE VAPOR RECOVERY STRATEGY
IN 1985.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c. Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
116.3
67.1
123.7
< 0.1
5.3
4.2
316.6
47.6
364.2
0.7
0.9
1.5
5.8
1.4
28.7
3.4
42.3
406.5
NMHC
tons/day
32.8
15.1
il.4
< 0.1
1.1
0.9
61.2
9.2
70.4
13.5
0.4
1.7
38.0
3.1
2.4
59.1
129. 5
E-13
-------
Table E-10. EMISSIONS BREAKDOWN FOR THE CARPOOLING STRATEGY
IN 1985.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f. Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c. Industrial
d. Miscellaneous
5. Airports
6. Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
110.4
63.7
123.7
< 0.1
5.3
4.2
307.3
45.2
352.5
0.7
0.9
1.5
5.8
1.4
28.7
3.4
42.3
394.8
NMHC
tons/day
31.2
14.3
11.4
< 0.1
1.1
0.9
58.8
8.8
67.6
13.5
--
0.4
1.7
47.6
3.1
2.4
68.7
136.3
E-14
-------
Table E-ll. EMISSIONS BREAKDOWN FOR THE WORK AND DRIVING SCHEDULE
SHIFTS STRATEGY IN 1985.
Category
1 . Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
116.1
67.0
123.0
< 0.1
5.3
1.2
315.6
47.5
363.1
0.7
- 0.9
1.5
5.8
1.*
28.7
3.4
42.3
405.4
NMHC
tons/day
32.8
15.1
11.3
< 0.1
1.0
0.9
61.1
9.2
70.3
13.5
0.4
1.7
47.6
3.1
2.4
68.7
139.0
E-15
-------
Table E-12. EMISSIONS BREAKDOWN FOR THE BASE CASE IN 1990.
Category
1 . Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
59.8
50.3
135.2
< 0.1
6.2
1.*
252.9
29.6
282.5
0.6
1.0
1.6
7.8
1.6
32.3
3.8
48.7
331.2
NMHC
tons/day
21.1
11.7
10.4
< 0.1
1.2
0.4
44.8
6.0
50.8
13.5
0.4
2.3
44.9
3.2
2.7
67.0
117.8
E-16
-------
Table E-13. EMISSIONS BREAKDOWN FOR THE INSPECTION/MAINTENANCE
STRATEGY IN 1990.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c. Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
46.4
39.2
120.3
< 0.1
5.5
1.1
212.5
23.1
235.6
0.6
1.0
1.6
7.8
1.6
32.3
3.8
48.7
284.3
NMHC
tons/day
13.3
7.4
9.6
< 0.1
1.1
0.3
31.7
3.3
35.0
13.5
--
0.4
2.3
44.9
3.2
2.7
67.0
102.0
E-17
-------
Table E-14. EMISSIONS BREAKDOWN FOR THE PERIODIC MAINTENANCE
STRATEGY IN 1990.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f. Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
b. Area Sources
a. Residential
b. Comm./Inst.
c. Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
38.9
32.7
87.9
< 0.1
4.0
0.9
164.4
19.2
183.6
0.6
1.0
1.6
7.8
1.6
32.3
3.8
48.7
232.3
NMHC
tons/day
13.9
7.7
6.9
< 0.1
0.8
0.3
29.6
4.0
33.6
13.5
0.4
2.3
44.9
3.2
2.7
67.0
100.6
E-18
-------
Table E-15. EMISSIONS BREAKDOWN FOR THE VAPOR RECOVERY STRATEGY
IN 1990.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c. Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
59.8
50.3
135.2
< 0.1
6.2
1.*
252.9
29.6
282.5
0.6
1.0
1.6
7.8
1.6
32.3
3.8
48.7
331.2
NMHC
tons/day
21.1
11.7
10.4
< 0.1
1.2
0.4
44.8
6.0
50.8
13.5
0.4
2.3
27.1
3.2
2.7
49.2
100.0
E-19
-------
Table E-16. EMISSIONS BREAKDOWN FOR THE CARPOOLING STRATEGY
IN 1990.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f. Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
if-. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
CO
tons/day
54.7
46.0
135.2
< 0.1
6.2
1.4
243.5
27.1
270.6
0.6
1.0
1.6
7.8
1.6
32.3
3.8
48.7
NMHC
tons/day
19.4
10.8
10.4
< 0.1
1.2
.4
42.2
5.5
47.7
13.5
--
0.4
2.3
44.9
3.2
2.7
67.0
TOTAL
318.3
114.7
E-20
-------
Table E-17. EMISSIONS BREAKDOWN FOR THE BICYCLE SYSTEM
IN 1990.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f. Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c. Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
59.4
50.0
135.2
<0.1
6.2
1.4
252.3
29.4
281.7
0.6
1.0
1.6
7.8
1.6
32.3
3.8
48.7
330.4
NMHC
torn/day
21.Q
11*6
10.4
< 0.1
1.2
.4
44.6
6.0
50.6
13.5
ğ*
0.4
2.3
44.9
3.2
2.7
67.0
117.6
E-21
-------
Table E-18. EMISSIONS BREAKDOWN FOR THE BASE CASE IN 1995.
Category
1 . Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f. Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5. Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
65.4
57.2
155.4
< 0.1
7.2
1.6
286.9
31.7
318.6
0.6
1.1
1.7
10.1
1.8
36.1
4.2
55.6
374.2
NMHC
tons/day
21.9
11.1
12.7
< 0.1
1.5
0.5
47.7
6.5
54.1
13. 4
0.4
2.9
39.8
3.4
3.0
62.9
117.0
E-22
-------
Table E-19. EMISSIONS BREAKDOWN FOR THE INSPECTION/MAINTENANCE
STRATEGY IN 1995.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON- TRAFFIC
TOTAL
CO
tons/day
51.0
44.6
138.3
< 0.1
6.4
1.3
241.6
24.8
266.4
0.6
1.1
1.7
10.1
1.8
36.1
4.2
55.6
322.0
NMHC
tons/day
13.8
7.0
11.8
< 0.1
1.4
0.3
34.3
4.1
38.4
13.4
--
0.4
2.9
39.8
3.4
3.0
62.9
101.3
E-23
-------
Table E-20. EMISSIONS BREAKDOWN FOR THE PERIODIC MAINTENANCE
STRATEGY IN 1995.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f. Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
42.5
37.2
101.0
< 0.1
4.7
1.1
186.5
20.6
207.1
0.6
1.1
1.7
10.1
1.8
36.1
4.2
55.6
262.7
NMHC
tons/day
14.4
7.3
8.4
< 0.1
1.0
0.3
31.4
4.3
35.7
13.4
. _
0.4
2.9
39.8
3.4
3.0
62.9
98.6
E-24
-------
Table E-21. EMISSIONS BREAKDOWN FOR THE VAPOR RECOVERY STRATEGY
IN 1995.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c. Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
65.4
57.2
155.4
< 0.1
7.2
1.6
286.9
31.7
318.6
0.6
1.1
1.7
10.1
1.8
36.1
4.2 .
55.6
374.2
NMHC
tons/day
21.9
11.1
12.7
< 0.1
1.5
0.5
47.7
6.0
53.7
13.4
0.4
2.9
12.0
3.4
3.0
35.1
88.8
E-25
-------
Table E-22. EMISSIONS BREAKDOWN FOR THE CARPOOLING STRATEGY
IN 1995.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
CO
tons/day
57.5
50.4
155.4
< 0.1
7.2
1.6
272.1
27.9
300.0
0.6
1.1
1.7
10.1
1.8
36.1
4-2
55.6
NMHC
tons/day
19.5
9.9
12.7
< 0.1
1.5
0.5
44.1
5.8
49.9
13.4
0.4
2.9
39.8
3.4
3.0
62.9
TOTAL
355.6
112.8
E-26
-------
Table E-23. EMISSIONS BREAKDOWN FOR THE BICYCLE SYSTEM STRATEGY
IN 1995.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c. Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
65.0
56.9
155.4
< 0.1
7.2
1.6
2S6.1
31.5
317.6
0.6
1.1
1.7
10.1
1.8
36.1
4.2
55.6
373.2
NMHC
tons/day
21.7
11.1
12.7
< 0.1
1.5
0.4
47.4
6.4
53.8
13.4
--
0.4
2.9
39.8
3.4
3.0
62.9
116.7
E-27
-------
Table E-24. EMISSIONS BREAKDOWN FOR THE WORK AND DRIVING SHIFT
STRATEGY IN 1995.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5. Airports
6. Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
65.2
57.1
154.5
< 0.1
7.1
1.6
285.5
31.7
317.2
0.6
1.1
1.7
10.1
1.8
36.1
4.2
55.6
372.8
NMHC
tons/day
21.9
11.1
12.7
< 0.1
1.5
0.5
47.7
6.5
54.1
13.4
--
0.4
2.9
39.8
3.4
3.0
62.9
117.0
E-28
-------
Table E-25. EMISSIONS BREAKDOWN FOR THE BASE CASE IN 2000.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
74.4
65.6
177.9
< 0.1
8.1
1.8
327.8
38.9
366.7
0.6
1.2
1.9
13.5
2.0
39.7
4.6
63.5
430.2
NMHC
tons/day
24.6
12.7
14.5
< 0.1
1.7
.5
54.0
7.0
61.0
13.4
0.5
3.9
44.3
3.5
3.3
68.9
129.9
E-29
-------
Table E-26. EMISSIONS BREAKDOWN FOR THE INSPECTION/MAINTENANCE
STRATEGY IN 2000.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5 . Airports
6. Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
58.0
51.1
158.3
< 0.1
7.0
1.*
275.8
30.3
306.1
0.6
1.2
1.9
13.5
2.0
39.7
4.6
63.5
369.6
NMHC
tons/day
15.5
8.0
13.5
< 0.1
1.6
0.3
38.9
4.4
43.3
13.4
--
0.5
3.9
44.3
3.5
3.3
68.9
112.2
E-30
-------
Table E-27. EMISSIONS BREAKDOWN FOR THE PERIODIC MAINTENANCE
STRATEGY IN 2000.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f. Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
48.4
42.6
115.6
< 0.1
5.3
1.2
213.1
25.3
238.4
0.6
1.2
1.9
13.5
2.0
39.7
4.6
63.5
302.9
NMHC
tons/day
16.2
8.4
9.6
< 0.1
1.1
0.3
35.6
4.6
40.2
13.4
0.5
3.9
44.3
3.5
3.3
68.9
109.1
E-31
-------
Table E-28. EMISSIONS BREAKDOWN FOR THE VAPOR RECOVERY STRATEGY
IN 2000.
Category
1 . Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c . Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
74. 4
65.6
177.9
< 0.1
8.1
1.8
327.8
38.9
366.7
0.6
1.2
1.9
13.5
2.0
39.7
4.6
63.5
430.2
NMHC
tons/day
24.6
12.7
14.5
< 0.1
1.7
.5
54.0
7.0
61.0
13.4
0.5
3.9
13.3
3.5
3.3
37.9
98.9
E-32
-------
Table E-29. EMISSIONS BREAKDOWN FOR THE CARPOOLING STRATEGY IN
2000.
Category
1. Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c. Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
62.9
55.4
177.9
< 0.1
8.1
1.8
304.3
32.9
337.2
0.6
1.2
1.9
13.5
2.0
39.7
4.6
63.5
400.7
NMHC
tons/day
21.2
10.9
14.5
< 0.1
1.7
0.5
48.8
6.0
54.8
13.4
__
0.5
3.9
44.3
3.5
3.3
68.9
123.7
E-33
-------
Table E-30. EMISSIONS BREAKDOWN FOR THE BICYCLE SYSTEM STRATEGY
IN 2000.
Category
1 . Primary Traffic
a. Light Duty Gas Vehicles
b. Light Duty Gas Trucks
c. Heavy Duty Gas Trucks
d. Light Duty Diesel Vehicles
e. Heavy Duty Diesel Vehicles
f . Motorcycles
TOTAL
2. Secondary Traffic
TOTAL TRAFFIC
3. Point Sources
4. Area Sources
a. Residential
b. Comm./Inst.
c. Industrial
d. Miscellaneous
5 . Airports
6 . Railroads
TOTAL NON-TRAFFIC
TOTAL
CO
tons/day
74.0
65.2
177.9
< 0.1
8.1
1.8
327.0
38.7
365.7
0.6
1.2
1.9
13.5
2.0
39.7
ft. 6.
63,5
429.2
NMHC
tons/day
24.5
12.6
14.5
< 0.1
1.7
0.5
53.8
7.0
60.8
13.4
0.5
3.9
44.3
3.5
3.3
68.9
129.7
E-34
-------
APPENDIX F
Description of the APRAC-II Model
-------
APRAC-1A is a diffusion model developed by Ludwig, et al (1970) for
computing the concentrations of inert, vehicle-generated pollutants at any
point within a city. The acronym APRAC stands for Air Pollution Research
Advisory Committee, under whose auspices the development of the model
was conducted. The members of this committee were drawn from the
Coordinating Research Council and the Environmental Protection Agency.
This model is basically a modified version of the receptor-oriented
Gaussian plume formulation developed by Clarke (1964). The source code is
contained in the User's Network for Applied Modeling of Air Pollution
(UNAMAP) available on magnetic tape through the National Technical
Information Service. The program is written in FORTRAN IV for an IBM
360/50 computer but is easily adapted to other systems with a FORTRAN IV
compiler. Instructions in running the program can be found in the User's
Manual for the APRAC-1A Urban Diffusion Model Computer Program
(Mancuso, et al, 1972).
Three different types of analyses can be performed using this model:
synoptic, climatological, and grid point. There is also a street canyon option
for synoptic and climatological models. The synoptic model gives temporal
variations of hourly pollution concentrations at up to ten receptor points.
The climatological model gives concentration frequency distributions at one
receptor based on historical meteorological and traffic input data. The grid
point model gives an average concentration at particular hour at up to 625
receptor points.
F.I The Basic Model
The model uses a combination of the "Gaussian plume" and "box" model
diffusion formulations. Basically, the Gaussian plume model assumes that
the vertical concentration profile from a crosswind line source is Gaussian in
shape as shown in Figure F-l. The spread of this vertical concentration
distribution is described by the standard deviation, a , taken to have the
£ğ
form
F-l
-------
O Depends Upon
Travel Distance
Atmosphere Stability
Gaussian Vertical
Concentration Profile
Line
Source
Distance
Figure F-l. Vertical Diffusion According to Gaussian Formulation.
10
10
10" 103 10"*
Downwind Distance - meters
10
Figure F-2. Vertical Diffusion Asa Function of Travel Distance and
Stability Category, As Revised For Urban Conditions.
F-2
-------
= axb (F-l)
where x is the downwind distance and the parameters a and b depend upon
atmospheric stability. The curves in Figure F-2 represent conditions from
extremely unstable (A) to moderately stable (E).
When vertical mixing is inhibited, the box model is applied to emissions
from sources relatively distant from the receptor. The receptor is the point
for which the concentrations are being calculated. Emissions tend to
become uniformly distributed in the vertical up to the limiting mixing height
after sufficient travel has taken place.
The models are applied to ten area sources, each of which is assumed
to have source emissions spread uniformly throughout. These area sources
are oriented in the upwind direction as shown in Figure F-3. The outer
sectors have an angular width of 22.5°, corresponding to the plume width
(+2 a) predicted by Gifford (1961) for slightly unstable conditions. The inner
sectors have an angular width of 45°. These broader sectors allow for larger
initial dispersion, as observed by Pooler (1966) and McElroy (1969). The
logarithmic spacing of the area boundaries allows the nearby sources to be
considered in greater detail than the farther sources, whose individual
contributions tend to be merged during their longer travel.
The contributions of each of the ten area sources to the CO
concentration at the receptor are computed individually with one of the
simple formulations given below. For the closer segments the Gaussian
formulation is used to obtain the concentration C. resulting from emissions
in the i segment:
0.8 Q . . / \-l / 1-b. 1-b.
where Q.. is the average area emission rate(gm m s ) u is the transport
wind speed (ms ), and a. and b. are the constants appropriate to the
F-3
-------
16 km
2 1
71
Receptor
Point
1000 m
500
Expanded View of
Annular Segments
Within 1 km of
Receptor
250
125
Receptor
Point
FIGURE F-3. Diagram of segments used for spatial partitioning of emissions.
-------
segment and atmospheric stability class j. The x's are the distances to the
closest boundary of the segment designated by the subscript, i.
The model changes from the Gaussian formulation to the box model as
a distance where the two (in their respective line source formulations) give
equal surface concentration values. The box model concentration is given by
the following equation:
x. , - x.
(F-3)
where h is the mixing height. The contributions of the emissions in each
segment, as determined from Eqns. F-2 and F-3 are summed to obtain the
concentration at the receptor.
In order to apply Eqns. F-2 and F-3, the model requires the following
input variables:
1. traffic emissions
2. mixing height
3. atmospheric stability type
4. transport wind speed and direction
o Traffic Emissions
Emissions are computed in the model using a traffic inventory
consisting of a network of traffic road segments or links. Each link is
assigned an average daily traffic volume, based upon historical or forecast
data. It is identified in the computer memory by its length and the
geographical locations of its end points and is classified by roadway type on
the basis of vehicular speed. To take into account diurnal variations, daily
traffic volumes are multiplied by an adjustment factor to obtain traffic
volume for a particular hour.
F-5
-------
The CO emission rate, E, (gm/vehicle-miles) is obtained from the mean
vehicular speed, S (mph), by an empirical equation of the form
where a and ft are constants that depend on emissions control characteris-
tics and vehicular model mix. For cars produced since 1968, /J has been
0.48. Existing and potential legislation requires <* to decrease with time
(Table F-l). For future years, the effective value of a and /5 have to be
determined on the basis of the fraction of the total cars represented by each
model year (Johnson, et al, 1971; Dabberdt, et al, 1973; Ludwig, et al, 1972).
TABLE F-l. Values of a for cars produced after 1970.
Model Years a
1972-1974 160
1975-1979 16
After 1980 8
The total hourly CO emission for a given traffic link is the product of
three factors: the emission rate, the length of the link, and the hourly
traffic volume. For a given sector (Figure F-3) the emissions from all the
links or parts of links that fall within that sector were aggregated to
determine the average emissions.
o Mixing Height
The determination of mixing height was based on the assumption that
for an atmosphere which started out with a low-lying inversion early in the
morning, convection will be caused by ground heating and that the entire
convective (mixed) layer is adiabatically adjusted so that the erosion on the
inversion base will be a direct response to this adjustment. Thus, by using
the observed morning lapse rate and the surface temperature at a given hour
during the day, it was possible to determine the height of the mixing layer
F 6
-------
by the intersection of the morning sounding and a dry adiabat. This method
is fairly common (Holzworth, 1967) for meteorological application.
During the daylight hours, the surface temperatures at the airport
observation site are used. During the predawn hours, and for those cases
which showed a ground-based inversion, the mixing height over the city was
based on the urban heat island models of Summers (1966) and Ludwig (1968,
1970). These models developed empirical relationships between rural lapse
rates and the intensity of urban heat islands. After sunset the model
interpolates between the afternoon mixing depth and that for the predawn
hours of the following morning.
o Atmospheric Stability
Plume spread is a function of turbulence. This latter may be para-
meterized in terms of atmospheric stability. Following the works of Pasquili
(1961) and Turner (1964), atmospheric conditions are classified according to
prevailing insolation strength and wind speed for daytime conditions, and
according to cloud cover and wind speed for nighttime conditions (Table F-
2).
Insolation strength is computed using the equation
Insolation strength = k (1 - AN) sin 6
where k = a proportionality factor, depending on the solar constant,
and atmospheric transmission
A = the average albedo or reflectance of the clouds
N = the fraction of the sky obscured by cloud
0 = the elevation angle of the sun
F-7
-------
TABLE F-2. Stability categories.
Surface Winds
(Knots)
< 3
3-6
6-10
10-12
> 13
Daytime Insolation
Strong
1
1
2
3
3
Moderate
2
2
3
3
*
Slight
2
3
3
4
*
Night Clouds
>5/10
5
*
*
4
*
<4/10
5
5
*
*
*
*1 = extremely unstable
2 = moderately unstable
3 = slightly unstable
* = neutral
5 = slightly stable
F-8
-------
Insolation is slight when 0 < (1 - 0.5 N) sin 6 < 0.33; moderate when
0.33 < (1 - 0.5 N) sin 0 < 0.67, and strong when (1 - 0.5 N) sin 0 > 0.67.
o Wind Speed and Direction
The model assumes a uniform wind field over the entire study area.
This assumption is dictated by the fact that many cities have only one
weather observation station. This is not too serious when the study area has
relatively simple geography. However, the assumption becomes invalid when
the study area is dominated by local circulations, e.g., valley and mountain
winds, land and sea breezes, etc.
F.2 APRAC Model as Modified by AeroVironment - APRAC-II
The original version of the APRAC-1A model developed by SRI in 1972
has some obvious drawbacks.
Improvements of the model are presented below.
o Wind
The assumption of a uniform wind direction and speed for an entire
study region is one of the drawbacks. There is no a priori reason why wind
should be uniform over a city. In APRAC-II, a subroutine called WIND,
developed by SRI under an ongoing contract with EPA Region IX, is used to
interpolate wind at a given receptor.
In subroutine WIND, if only one wind, usually the airport observation,
is provided, then that value is used for every receptor location. If wind
observations are available from more than one location, this subroutine uses
all observations within ten kilometers of the receptor for the interpolation.
If no wind observations are available within ten kilometers, then the inter-
polation will be based on those data from those wind stations within 20
kilometers. If no observations are available within this larger radius, then
the airport wind (or whatever wind is first on the input list) is used.
F-9
-------
The interpolation scheme uses weighted averages of the wind com-
ponents. The weighting factors are inversely proportional to the square of
the distance between the receptor and the wind site. More weight is given
to wind observations when they are made directly upwind or downwind of the
receptor than when they are removed to one side. This feature is included
to reflect the tendency of winds to change more rapidly in cross-streamline
directions than along the streamlines.
The interpolation scheme used in this routine was derived from that
used by Heffter and Taylor (1975). The vector averaged wind is given by
_ IDA W
V =
R
ID. A.
where V = interpolated wind vector at the receptor
D. = distance weighting factor for the i wind observation
As noted earlier, the summation radius, R, is taken as 10 km unless there are
no wind observations within that distance. If there are none, R is increased
to 20 km. Figure F-4 illustrates the parameters used in the wind
interpolation scheme.
o Mixing Height
In the original version of APRAC-1A, mixing heights were computed in
the model from a morning temperature sounding and surface temperatures
during the day and from an empirical equation derived from Summer's (1966)
and Ludwig's works (1968, 1970) during the night. The modified model has
the capability of accepting precomputed mixing height for the hour being
modeled.
F-10
-------
Receptor
FIGURE F-4. Parameters used in wind interpolation scheme.
F-ll
-------
o Emissions
The model now accepts non-traffic and secondary traffic emissions and
assigns them into 1 mile by 1 mile grids. It also allows the input of an
indefinite number of roadway links in the primary network whereas the
original version limits the number of primary links to 1200.
Of all the drawbacks of the original APRAC-1A, the most serious one
has to do with the computation of traffic emissions. Since CO concen-
trations at a receptor depend a great deal on the emissions upwind, an
inaccurate specification of these emissions would unavoidably result in
errors in the model output. Emissions factors in the original APRAC-1A are
computed for the formula E = a S where E is the emission factor, S is the
mean vehicle speed, and a and /J are constants that depend on the
characteristics of the emission control devices and the mixture of old and
new model cars on the road. The computations of emission factors have
been greatly improved since the development of the APRAC-1A model. The
latest EPA approved procedure is now published in Supplement 5 of AP-^2.
Instead of calculating emissions, the model now accepts emissions precom-
puted for each primary link and for each hour of the day. Thus, future
changes in emission factors will no longer require modifying the model.
o Line Source Model
An additional feature of the modified model which the original one
does not have is the capability of more detailed analysis of the effect of
individual network links on specific receptor locations. The subroutine,
LINE, used in this computation, and the series of routines called by LINE are
an adaptation of the line source treatment used in SRI's ISMAP dispersion
model.
The traffic link is represented by a series of point sources whose total
emissions equal the link's total emissions. A distance between points that
will accurately represent the line source must be chosen. The maximum
F-12
-------
tolerable error resulting from the finite distance between point sources was
taken to be 5 percent. Thus,
= 0.05
(F-5)
ref
where X , is the concentration at a receptor resulting from some
reference point on the link, and X is the concentration from a point on the
link a distance A L away. The case in which the wind is perpendicular to the
link is the most sensitive to the spacing between point sources (AL).
Assuming the reference point to be on the centerline of the plume with the
wind perpendicular to the link, Eqn. F-5 can be solved for AL:
-2n (Q.95) a
(F-6)
The distance along the wind direction used for calculation of a in Eqn. F-
6 is the distance from the receptor to the nearest point on each link. To be
conservative, the routine uses one-half of the value of AL as the spacing.
Having found the spacing between point sources for the link, the
subroutine proceeds to calculate the CO concentration at the receptor for
each point source. The equation for the concentration from a point source is
-exp
-1/2
(dw>
exp
1/2 _
a (d )
z w
(F-7)
and
°z (dw> - f K
(F-8)
F-13
-------
where X is the CO concentration, gm m
p -1
u is the wind speed, m sec
Q is the point-source emission rate, gm sec
a (d ) is the lateral standard deviation of plume concentration, m
y w
o (d ) is the vertical standard deviation of plume concentration, m
z w
H is the emission height, m
d is the cross wind distance from point source to receptor, m
d is the distance along wind direction from point source to
receptor, m
a,b,f,g are the diffusion coefficients and exponents
c,h are the constants representing initial diffusion, m
The concentrations resulting from point sources on a link are summed
for each receptor and multiplied by the distance between point sources.
-------
F.3 References
Clarke, J.F. (196*): A simple diffusion model for calculating point con-
centrations from multiple sources. J. Air Poll. Con. Assoc. 1*, 3*7-
352.
Dabberdt, W.F., F.L. Ludwig and W.B. Johnson, Jr. (1973): Validation and
applications of an urban diffusion model for vehicular pollutants.
Atmos. Environ 7, 603-618.
Gifford, F.A. (1961): Uses of routine meteorological observation for es-
timating atmospheric dispersion. Nuclear Safety 2 (*), 47-51.
Heffter, J.L. and A.D. Taylor (1975): A regional-continental scale transport,
diffusion, and deposition model, Part I: Trajectory model. Nat. Ocean
and Atmos. Admin. Tech. Memo. ERL ARL-50, 1-16.
Holzworth, G.C. (1967): Mixing depths, wind speeds and air pollution poten-
tial for selected locations in the United States. J. Appl. Met. 6, 1039-
Johnson, W.B., W.F. Dabberdt, F.L. Ludwig and R.J. Allen (1971): Field
study for initial evaluation of an urban diffusion model for carbon
monoxide. National Technical Information Service Pub. No. PB-
203*69.
Ludwig, F.L. (1968): Urban temperature fields. Paper presented at WMO
Symposium on Urban Climates and Building Climatology, Brussels, 15-
28 October.
Ludwig, F.L. (1970): Urban air temperatures and their relation to
extraurban meteorological measurements. Paper presented at Ameri-
can Soc. Heat, Refrig. , and Vent. Eng., San Francisco, California,
January.
Ludwig, F.L., W.B. Johnson, A.E. Moon, and R.L. Mancuso (1970): A prac-
tical, multipurpose urban diffusion model for carbon monoxide. PB 196
003.
Ludwig, F.L. and W.F. Dabberdt (1972): Evaluation of the APRAC-1A urban
diffusion model for carbon monoxide. Stanford Research Institute.
Mancuso, R.L., and F.L. Ludwig (1972): User's manual for the APRAC-1A
urban diffusion model computer program. National Technical Informa-
tion Service Pub. No. PB 213091.
McElroy, J.L. (1969): A comparative study of urban and rural dispersion. J^
Appl. Met. 8, 19-31.
Pasquill, F. (1961): The estimation of the dispersion of windborne material.
Meteorol. Magazine 90 (1063), 33-*9.
F-15
-------
Pooler, F. (1966): A tracer study of dispersion over a city. J. Air Poll.
Cont. Assoc. U, 677-681.
Summers, P.W. (1966): The seasonal, weekly, and daily cycles of
atmospheric smoke content in central Montreal. 3. Air Poll. Cont.
Assoc. 16, fr32-438.
Turner, D.B. (1964): A diffusion model for an urban area. 3. of Applied Met.
3,83-91.
F-16
-------
APPENDIX G
Major Assumptions of the Air Quality Maintenance Analysis
-------
In order to facilitate updating of maintenance planning in the future,
the major assumptions made in the air quality maintenance analysis are
presented here.
I. CARBON MONOXIDE STANDARD ATTAINMENT
The predicted year of attainment of the carbon monoxide standard
under various control strategies involves assumptions concerning
meteorology, emissions, and control strategy effectiveness. All of these
assumptions influence APRAC-II output. APRAC-H was used to directly
forecast peak 8-hour CO readings for the base case, the work and driving
schedule shift control strategy, and the combined strategies of
inspection/maintenance and carpooling. Results of these APRAC-II runs
were used to forecast peak 8-hour CO readings under other strategies using
ratios of peak CO readings to CO emissions.
Meteorological assumptions involved the selection of the "severe-case"
regime. This regime was selected on the basis of "severe" 8-hour CO
readings at the monitoring sites. The second highest recorded 8-hour CO
reading was used to determine this severe case, since the first highest
reading was influenced by extensive controlled forest burning and, thus, it
was not possible to ascertain how conducive to high CO levels
meteorological conditions during that period would be. The meteorological
parameters used as input into APRAC-H (i.e., wind speed and direction,
surface temperature, cloud cover) were taken directly from the monitoring
sites except for the case of calm winds. APRAC-II would not accept cairn
winds. In this case, wind speeds were set at 1 m/s with a direction agreeing
with the general wind flow.
Assumptions made concerning base year and projected emissions are
presented in Appendices A through E. In summary, traffic link data was
supplied by Maricopa Association of Governments. Emission factors
presented in Supplement 5 to AP-42 (EPA, 1976) were applied using AVSUP5,
a computer program. Traffic emissions for 1980, 1990, and 2000 were
interpolated or extrapolated as explained in Appendix B. Non-traffic
emissions for the base year were obtained from "Emission Inventory Report
G-l
-------
for the Phoenix Study Area" (PES, 1976). Projections were made on the
basis of growth and emission factor adjustments as described in Appendix D.
Control strategy effectiveness data as it relates to emission reduction
is presented in Appendix E. This effectiveness data was provided by the
AQMA Technical Operations Committee.
Year of attainment was obtained by plotting peak 8-hour CO
concentration versus year for each strategy. The first complete year that
the peak 8-hour CO reading is predicted to remain below 9.0 ppm is
considered to be the year of attainment.
G-2
-------
II. OXIDANT STANDARD ATTAINMENT
The predicted year of attainment of the oxidant standard under various
control strategies involves assumptions similar to those concerning carbon
monoxide, although no meteorological assumptions are necessary other than
that implicit in the Appendix 3 method (40CFR51): climatology is assumed
constant from year to year.
The Appendix 3 method involves forecasting the reduction of hydro-
carbon emissions required to achieve the oxidant standard from the second
highest 1-hour oxidant concentration. Since 1975 was selected as base year,
the second high reading was 259 ug/m .
Control strategy effectiveness data was again provided by the AQMA
Technical Operations Committee and is presented in Appendix E.
Year of attainment was obtained by plotting NMHC emissions versus
year for each control strategy. The first complete year in which the NMHC
emissions are predicted to remain below the maximum allowable emissions is
considered to be the year of attainment.
Implicit in emission computations and projections were the following
population levels: 1.23 million for 1975, 1.5 million for 1980, 1.7 million for
1985, 2.0 million for 1990, 2.2 million for 1995, and 2.5 million for 2000.
G-3
-------
REFERENCES
Pacific Environmental Services, Inc., "Emission Inventory Report for the
Phoenix Study Area 1975-1995," August 1976.
U.S. Environmental Protection Agency. Compilation of Air Pollution
Emission Factors. Report AP42, Second Edition with supplements.
1976.
-------
APPENDIX H
Glossary
-------
GLOSSARY
Ambient Air; Any unconf ined portion of the atmosphere; the outside air.
Ambient Air Quality Standards; The level of air quality necessary to protect
the public health or welfare from any known or anticipated adverse
effects of a pollutant, as determined by the U.S. EPA.
AQMA; Air Quality Maintenance Area.
AQMATF; Air Quality Maintenance Area Task Force.
AV; AeroVironment Inc.
CO; Carbon Monoxide.
Cold operation; Representative of vehicle start-up after a long engine-off
period.
Colorimetric detection; An analysis method whereby the amount of a
pollutant is determined by the color change in a reagent through which
a gas containing the pollutant is bubbled.
EPA; Environmental Protection Agency.
Flame ionization gas chromatography; An analysis method whereby a gas
sample is passed through a column containing packing material which
allows each component to pass through at a different rate. The
amount of certain components (e.g. CH^) is then determined by
detecting the amount of increase in ion intensity resulting from the
introduction into a hydrogen flame of the sample air.
Hot start-up condition; Representative of vehicle start-up after a short
engine-off period.
H-l
-------
Inert pollutants; Those gaseous pollutants (e.g., CO) that are relatively
nonreactive (inert) with other gaseous or particulate species in the
atmosphere.
Inversion; A layer of air in which temperature increases with height; a
departure from the normal meteorological situation in which
temperature decreases upwards from the ground. Such layers
generally trap air pollutants by suppressing any upward mixing.
MAG:Maricopa Association of Governments.
mg/m : Milligrams per cubic meter; weight of a pollutant per cubic meter
of air.
Mixing height; The height of the top of the mixing layer.
Mixing layer; That atmospheric layer through which pollutants are presumed
to mix by virtue of air mass movement (convection) caused by daytime
heating at the surface.
Model; A mathematical representation of the atmosphere or of particular
atmospheric processes.
NDIR spectroscopy; An analysis method whereby the amount of infrared
radiation absorbed in a particular wavelength determines the
concentration of a gaseous component (pollutant).
NEDS; National Emissions Data System.
Neutral buffered potassium iodide colorimetric analysis; A colorimetric
detection method for oxidant using neutral buffered potassium iodide
as the reagent.
NMHC; Non-methane hydrocarbon.
H-2
-------
Oxidant: Any oxygen containing substance that reacts chemically in the air
to produce new substances. Oxidants are the primary contributors to
photochemical smog.
PES; Pacific Environmental Services.
Photochemical pollutants; Those gaseous pollutants (e.g., ozone) that are
products of photochemical reactions in the atmosphere.
ppm: Volumetric ratio of pollutant concentrations to ambient air
concentrations, (parts of pollutants per million parts of air).
Precursors (of ozone); Pollutants (generally NMHC and oxides of nitrogen)
which, under the influence of ultraviolet radiation, react to form
ozone.
Severe case; That combination of winds, mixing height, and atmospheric
stability which accompanies high levels of atmospheric pollutants.
Spatial distribution; Variation over the study region.
Stagnation; Persistence of a given volume of stable air over a region,
permitting an abnormal buildup of pollutants from sources within the
region.
Stable; A condition of the atmosphere in which vertical mixing is
suppressed.
Unstable; A condition of the atmosphere which favors vertical mixing.
Ug/m : Micrograms per cubic meter; weight of a pollutant per cubic meter
of air.
H-3
-------
UV photometry; An analysis method whereby the amount of a pollutant
present is determined by the amount of ultraviolet radiation absorbed
by that pollutant.
A more complete glossary may be obtained from the "Glossary of
Terms Frequently Used in Air Pollution." Published by the American
Meteorological Society (Pub. Gap-100, Reprinted 8/1/72). Another source is
"Common Environmental Terms, A Glossary", put out by U.S.E.P.A (Revised
Nov. 1974).
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