2002 Periodic Emissions Inventory
for
Carbon Monoxide

for the
Maricopa County, Arizona, Nonattainment Area

June 2004

This emissions inventory has been prepared by:
Bob Downing
Dena Konopka
Matt Poppen
Eric Raisanen
Maricopa County Environmental Services Department
1001 N. Central Ave. Suite 250
Phoenix, AZ 85004

Ruey-in Chiou
Steve Ochs
Roger Roy
Maricopa Association of Governments
302 N. 1st Ave. Suite 300
Phoenix, AZ 85003

with additional contributions and/or review by:
Randy Sedlacek
Peter Hyde
Arizona Department of Environmental Quality
1101 W. Washington St.
Phoenix, AZ 85007
Bob Farrell
Pima County Air Quality Control District
P.O. Box 987
Florence, AZ 85232
Alison K. Pollock
Cuong Tran
Christian Lindjhem
ENVIRON International Corp.
101 Rowland Way
Novato, CA 94945

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Table of Contents
1. Introduction .............................................................................................................................. 1
1.1
1.2
1.3
1.4
1.5

Overview............................................................................................................................ 1
Agencies responsible for the emissions inventory............................................................. 1
Temporal scope.................................................................................................................. 2
Geographic scope............................................................................................................... 2
Overview of local demographic and land-use data............................................................ 3
1.5.1 Demographic data ................................................................................................... 3
1.5.2 Land-use data .......................................................................................................... 3
1.6 Emissions overview by source category............................................................................ 4
1.6.1 Point sources ........................................................................................................... 4
1.6.2 Area sources............................................................................................................ 5
1.6.3 Nonroad mobile sources ......................................................................................... 5
1.6.4 Onroad mobile sources ........................................................................................... 6
1.6.5 Summary of emissions by source category............................................................. 6
1.7 References.......................................................................................................................... 8
2. Point Sources ............................................................................................................................ 9
2.1 Introduction and scope....................................................................................................... 9
2.2 Identification of CO point sources................................................................................... 10
2.3 Procedures for estimating emissions from point sources ................................................ 14
2.3.1 Example 1: Ocotillo Power Plant.......................................................................... 15
2.3.2 Example 2: Imsamet of Arizona ........................................................................... 15
2.4 Emission reduction credits............................................................................................... 18
2.5 CO point source emissions by process type .................................................................... 19
2.6 Summary of point source emissions ................................................................................ 23
2.7 Quality assurance / quality control procedures................................................................ 23
2.7.1 Emission survey preparation and data collection.................................................. 23
2.7.2 Submission processing.......................................................................................... 24
2.7.3 Analysis of annual point source emissions data for this inventory....................... 25
2.8 References........................................................................................................................ 25
3. Area Sources ........................................................................................................................... 27
3.1 Scope and methodology................................................................................................... 27
3.2 Fuel combustion............................................................................................................... 28
3.2.1 Industrial natural gas............................................................................................. 28
3.2.2 Industrial fuel oil................................................................................................... 30
3.2.3 Commercial/institutional natural gas .................................................................... 31
3.2.4 Commercial/institutional fuel oil .......................................................................... 33
3.2.5 Residential natural gas .......................................................................................... 34
3.2.6 Residential wood combustion ............................................................................... 35
3.2.7 Residential fuel oil ................................................................................................ 37
3.2.8 Summary of all area-source fuel combustion ....................................................... 37
3.3 Industrial processes.......................................................................................................... 38
3.3.1 Chemical manufacturing....................................................................................... 38
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3.4

3.5

3.6
3.7
3.8

3.3.2 Commercial cooking............................................................................................. 39
3.3.3 State-permitted portable sources........................................................................... 41
3.3.4 Industrial processes not elsewhere classified (NEC) ............................................ 42
3.3.5 Summary of all area-source industrial processes.................................................. 42
Waste treatment and disposal .......................................................................................... 43
3.4.1 On-site incineration............................................................................................... 43
3.4.2 Open burning ........................................................................................................ 43
3.4.3 Landfills ................................................................................................................ 46
3.4.4 Summary of all area-source waste treatment and disposal ................................... 47
Miscellaneous area sources.............................................................................................. 47
3.5.1 Other combustion.................................................................................................. 47
3.5.1.1 Wildfires and brush fires ......................................................................... 47
3.5.1.2 Structure fires........................................................................................... 49
3.5.1.3 Vehicle fires............................................................................................. 50
3.5.1.4 Engine testing .......................................................................................... 51
3.5.2 Health services: crematories ................................................................................. 51
3.5.3 Accidental releases................................................................................................ 52
3.5.4 Summary of all miscellaneous area sources ......................................................... 52
Summary of area source emissions.................................................................................. 53
Quality assurance / quality control procedures................................................................ 53
References........................................................................................................................ 55

4. Nonroad Mobile Sources........................................................................................................ 57
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
4.12
4.13
4.14
4.15
4.16

Introduction...................................................................................................................... 57
Agricultural equipment.................................................................................................... 59
Airport ground support equipment .................................................................................. 60
Commercial equipment.................................................................................................... 61
Construction and mining equipment................................................................................ 62
Industrial equipment ........................................................................................................ 62
Lawn and garden equipment............................................................................................ 63
Logging equipment.......................................................................................................... 64
Pleasure craft ................................................................................................................... 64
Railway maintenance equipment ..................................................................................... 65
Recreational equipment ................................................................................................... 66
Aircraft............................................................................................................................. 66
Locomotives .................................................................................................................... 70
Summary of all nonroad mobile source emissions .......................................................... 71
Quality assurance procedures .......................................................................................... 71
References........................................................................................................................ 71

5. Onroad Mobile Sources ......................................................................................................... 73
5.1
5.2
5.3
5.4
5.5

Introduction...................................................................................................................... 73
VMT estimation procedure.............................................................................................. 73
Speed estimation procedure............................................................................................. 76
Monthly VMT factors...................................................................................................... 77
Emission factor estimation procedure ............................................................................. 78
5.5.1 Emission factor model .......................................................................................... 78

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5.5.2 Development of model inputs............................................................................... 79
5.5.3 Model outputs ....................................................................................................... 83
5.5.4 Summary of emission factors................................................................................ 83
5.5.5 Emission estimates................................................................................................ 84
5.6 Summary of CO emissions from onroad mobile sources .............................................. 101
5.7 Quality assurance process.............................................................................................. 105
5.7.1 VMT estimates.................................................................................................... 105
5.7.2 Emission factor estimates ................................................................................... 105
5.7.3 Quality review of 2002 periodic CO emissions inventory.................................. 105
5.8 References...................................................................................................................... 106

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List of Tables
Table 1.2–1.
Table 1.5–1.
Table 1.5–2.
Table 1.6–1.
Table 1.6–2.
Table 1.6–3.

Chapter authors and QA/QC contacts....................................................................... 1
Demographic profile of Maricopa County and the CO nonattainment area............. 3
Land-use categories used to apportion emissions..................................................... 4
Summary of annual and season-day point source emissions, by source category.... 4
Summary of annual and season-day area source emissions, by source category. .... 5
Summary of annual and season-day CO emissions from nonroad mobile
sources...................................................................................................................... 6
Table 1.6–4. Annual and season-day emissions from onroad mobile sources in Maricopa
County. ..................................................................................................................... 6
Table 1.6–5. Summary of annual CO emissions (tons/yr) in the CO nonattainment area, by
source category, 1990–2002. ................................................................................... 8
Table 1.6–6. Summary of CO season-day emissions (lbs/day) in the CO nonattainment area,
by source category, 1990–2002................................................................................ 8
Table 2.2–1. Number of stationary point sources by location and permitting authority............. 10
Table 2.2–2. Name and location of all point sources. ................................................................. 10
Table 2.3–1. Annual and CO season-day point source emissions, by facility. ........................... 16
Table 2.4–1. CO emission reduction credits. .............................................................................. 18
Table 2.5–1. Annual and CO season-day point source emissions, by process type. .................. 19
Table 2.6–1. Summary of annual and season-day point source emissions, by source
category. ................................................................................................................. 23
Table 3.1–1. List of area source categories................................................................................. 27
Table 3.2–1. Natural gas sales data from Maricopa County natural gas suppliers. .................... 28
Table 3.2–2. Emission factors and annual emissions from area-source industrial natural gas
combustion, by combustion type. .......................................................................... 29
Table 3.2–3. Annual and season-day emissions from area-source industrial natural gas
combustion. ............................................................................................................ 29
Table 3.2–4. Emission factors and annual emissions from area-source industrial fuel oil
combustion, by combustion type. .......................................................................... 31
Table 3.2–5. Annual and season-day emissions from area-source industrial fuel oil
combustion. ............................................................................................................ 31
Table 3.2–6. Emission factors and annual emissions from area-source
commercial/institutional natural gas combustion, by combustion type. ................ 32
Table 3.2–7. Annual and season-day emissions from area-source commercial/institutional
natural gas combustion........................................................................................... 32
Table 3.2–8. Emission factors and annual emissions from area-source
commercial/institutional fuel oil combustion, by combustion type. ...................... 34
Table 3.2–9. Annual and season-day emissions from area-source commercial/institutional
fuel oil combustion................................................................................................. 34
Table 3.2–10. Annual and season-day emissions from residential natural gas combustion. ........ 35
Table 3.2–11. Annual and season-day emissions from residential wood combustion.................. 37
Table 3.2–12. Annual and season-day emissions from residential fuel oil combustion. .............. 37
Table 3.2–13. Summary of annual and season-day area source fuel combustion......................... 37
Table 3.3–1. NAICS codes and descriptions for chemical manufacturing. ................................ 38
Table 3.3–2. Annual and season-day emissions from area-source chemical manufacturing...... 39
Table 3.3–3. Maricopa County restaurants, by type. .................................................................. 40
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Table 3.3–4.
Table 3.3–5.
Table 3.3–6.
Table 3.3–7.
Table 3.3–8.
Table 3.3–9.
Table 3.4–1.
Table 3.4–2.
Table 3.4–3.
Table 3.4–4.
Table 3.4–5.

Annual emissions from commercial cooking, by equipment type......................... 40
Season-day emissions from commercial cooking, by equipment type. ................. 40
Annual and season-day emissions from commercial cooking. .............................. 40
Emissions from ADEQ-permitted portable sources, by permit type. .................... 42
Annual and season-day emissions from other industrial processes. ...................... 42
Summary of annual and season-day area source industrial processes. .................. 42
Annual and season-day emissions from on-site incineration................................. 43
2002 Maricopa County burn permit activity data. ................................................. 44
Emission and fuel loading factors for open burning. ............................................. 44
Annual emissions from open burning (tons/yr). .................................................... 45
Surrogate land-use classes, ratios and annual emissions from open burning in
the CO NAA........................................................................................................... 45
Table 3.4–6. Season-day emissions (lbs/day) from open burning. ............................................. 46
Table 3.4–7. Annual and season-day emissions from landfills................................................... 46
Table 3.4–8. Summary of annual and season-day emissions from waste treatment and
disposal................................................................................................................... 47
Table 3.5–1. Emission and fuel loading factors for wildfires and brush fires. ........................... 47
Table 3.5–2. Annual emissions from wildfires and brush fires (tons/yr).................................... 48
Table 3.5–3. Season-day emissions from wildfires and brush fires (lbs/day)............................. 48
Table 3.5–4. Estimated material burned, emission and fuel loading factors for structure fires.. 49
Table 3.5–5. Annual and season-day emissions from structure fires.......................................... 50
Table 3.5–6. Estimated material burned, emission and fuel loading factors for vehicle fires. ... 50
Table 3.5–7. Annual and season-day emissions from vehicle fires. ........................................... 51
Table 3.5–8. Annual and season-day emissions from engine testing. ........................................ 51
Table 3.5–9. Annual and season-day emissions from crematories. ............................................ 52
Table 3.5–10. Annual and season-day emissions from accidental releases. ................................. 52
Table 3.5–11. Summary of annual and season-day emissions from all miscellaneous area
sources.................................................................................................................... 52
Table 3.6–1. Summary of annual and season-day area source emissions, by source category... 53
Table 4.1–1. Default weekday and weekend day activity allocation fractions. .......................... 59
Table 4.2–1. Annual emissions from agricultural equipment in Maricopa County.................... 59
Table 4.2–2. Annual emissions from agricultural equipment in the CO nonattainment area. .... 60
Table 4.2–3. Total seasonal and season-day emissions from agricultural equipment in
Maricopa County.................................................................................................... 60
Table 4.2–4. Season-day emissions from agricultural equipment in CO nonattainment area. ... 60
Table 4.3–1. Annual emissions from airport ground support equipment.................................... 61
Table 4.3–2. CO season-day emissions from airport ground support equipment. ...................... 61
Table 4.4–1. Annual emissions from commercial equipment..................................................... 61
Table 4.4–2. CO season-day emissions from commercial equipment. ....................................... 62
Table 4.5–1. Annual emissions from construction and mining equipment................................. 62
Table 4.5–2. CO season-day emissions from construction and mining equipment. ................... 62
Table 4.6–1. Annual emissions from industrial equipment. ....................................................... 63
Table 4.6–2. CO season-day emissions from industrial equipment............................................ 63
Table 4.7–1. Annual emissions from lawn and garden equipment. ............................................ 63
Table 4.7–2. CO season-day emissions from lawn and garden equipment................................. 64
Table 4.8–1. Annual emissions from logging equipment. .......................................................... 64
Table 4.8–2. CO season-day emissions from logging equipment............................................... 64
Table 4.9–1. Annual emissions from pleasure craft equipment.................................................. 65
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Table 4.9–2. CO season-day emissions from pleasure craft equipment. .................................... 65
Table 4.10–1. Annual emissions from railway maintenance equipment. ..................................... 65
Table 4.10–2. CO season-day emissions from railway maintenance equipment.......................... 66
Table 4.11–1. Annual emissions from recreational equipment..................................................... 66
Table 4.11–2. CO season-day emissions from recreational equipment. ....................................... 66
Table 4.12–1. NEI default emission factors, by aircraft type. ...................................................... 67
Table 4.12–2. 2002 airport activity data and emission calculation methods. ............................... 68
Table 4.12–3. Emission factors, and annual and CO season-day emissions, by airport and
aircraft type. ........................................................................................................... 69
Table 4.13–1. Fuel use, emission factors, and annual emissions from locomotives in
Maricopa County.................................................................................................... 70
Table 4.13–2. Annual CO nonattainment area emissions from locomotives. ............................. 70
Table 4.13–3. CO season-day emissions from locomotives. ........................................................ 71
Table 4.14–1. Summary of annual and season-day CO emissions from nonroad mobile
sources.................................................................................................................... 71
Table 5.2–1. 2002 HPMS VMT by area type and facility type for the CO nonattainment area
(annual average daily traffic). ................................................................................ 74
Table 5.2–2. 2002 HPMS VMT by area type and facility type for Maricopa County (annual
average daily traffic) .............................................................................................. 75
Table 5.3–1. Average daily speeds (mph) for the 2002 periodic emissions inventory. .............. 76
Table 5.4–1. Average daily VMT adjustment factors by month................................................. 77
Table 5.4–2. Average daily VMT during 2002 carbon monoxide season for the CO
nonattainment area (November 2002–January 2003). ........................................... 78
Table 5.4–3. Average daily VMT during 2002 carbon monoxide season for Maricopa
County (November 2002–January 2003). .............................................................. 78
Table 5.5–1. Daily CO emissions in the CO nonattainment area, by vehicle class, facility
type and area type (peak CO season day). ............................................................. 85
Table 5.5–2. Daily CO emissions in Maricopa County, by vehicle class, facility type and
area type (peak CO season day). ............................................................................ 89
Table 5.5–3. Daily CO emissions in the CO nonattainment area, by vehicle class, facility
type and area type (annual average daily traffic). .................................................. 93
Table 5.5–4. Daily CO emissions in Maricopa County, by vehicle class, facility type and
area type (annual average daily traffic).................................................................. 97
Table 5.6–1. Daily CO emissions (kg/day) in the CO nonattainment area from onroad
mobile sources by vehicle class, area type and facility type (winter day). .......... 101
Table 5.6–2. Daily CO emissions (kg day) in Maricopa County from onroad mobile sources
by vehicle class, area type and facility type (winter day). ................................... 102
Table 5.6–3. Daily CO emissions (kg/day) in the CO nonattainment area from onroad
mobile sources by vehicle class, area type and facility type (annual average
day)....................................................................................................................... 103
Table 5.7–1. Comparison of CO emissions from onroad mobile sources and vehicle miles
traveled (VMT) in the CO nonattainment area, 1990–2002. ............................... 105

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List of Figures
Figure 1.4–1. Map of Maricopa County and the CO, ozone, and PM10 nonattainment areas. ...... 2
Figure 1.6–1. Annual emissions in the CO nonattainment area, by source category (tons/yr). .... 7
Figure 1.6–2. Season-day emissions in the CO nonattainment area, by source category
(lbs/day). .................................................................................................................. 7
Figure 2.7–1. Data flow for annual point source emission inventory reporting........................... 24

Appendices
Appendix 2.1 Instructions for Reporting 2002 Annual Air Pollution Emissions
Appendix 3.1 2002 Fire Department Survey Results
Appendix 5.1
Appendix 5.2
Appendix 5.3
Appendix 5.4
Appendix 5.5
Appendix 5.6
Appendix 5.7

Traffic Information
MOBILE6.2 Inputs, Outputs, and Spreadsheet
Vehicle Registration Data
Minimum and Maximum Temperature Calculations
VMT Reasonableness Calculations
FORTRAN Source Code for Emission Factor Weighting Program
Monthly Gasoline Data

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1.

Introduction

1.1 Overview
This 2002 periodic carbon monoxide (CO) emissions inventory was developed to meet requirements set forth in Title I of the Clean Air Act Amendments of 1990 (CAAA). The CAAA
require development of a baseline emission inventory and periodic revisions for areas that fail to
meet the National Ambient Air Quality Standards (NAAQS). A portion of Maricopa County is
classified as serious nonattainment for carbon monoxide.
This inventory includes emission estimates for carbon monoxide (CO) from point, area, nonroad
mobile, and onroad mobile sources. Note that totals shown in all tables may not equal the sum of
individual values due to independent rounding.

1.2 Agencies responsible for the emissions inventory
Maricopa County Environmental Services Department (MCESD) has primary responsibility for
preparing and submitting the 2002 Periodic Ozone Emissions Inventory for Maricopa County.
Stationary point, area, and nonroad mobile source emission estimates for aircraft and locomotives were prepared by MCESD. The remaining nonroad mobile emission estimates were
developed by ENVIRON International Corporation (Environ et al., 2003), with additional work
conducted by MCESD to develop estimates for the nonattainment area and a typical season day.
The Maricopa Association of Governments (MAG) prepared the onroad mobile emissions
estimates. Quality assurance and quality control (QA/QC) activities are described in each
chapter. The persons responsible for inventory preparation and QA/QC activities for each
chapter are listed in Table 1.2–1.
Table 1.2–1. Chapter authors and QA/QC contacts.
Chapter
Author(s)
Point Sources
Bob Downing
MCESD (602) 506-6790

QA/QC contact persons
Matt Poppen, Eric Raisanen and Dena
Konopka
MCESD (602) 506-6790

Area Sources

Matt Poppen, Eric Raisanen and
Dena Konopka
MCESD (602) 506-6790

Bob Downing
MCESD (602) 506-6790
Ruey-in Chiou and Scott DiBiase
MAG (602) 254-6300

Nonroad Mobile Sources

Matt Poppen and Eric Raisanen
MCESD (602) 506-6790

Bob Downing and Dena Konopka
MCESD (602) 506-6790
Ruey-in Chiou and Scott DiBiase
MAG (602) 254-6300

Onroad Mobile Sources

Roger Roy
MAG (602) 254-6300

Ruey-in Chiou
MAG (602) 254-6300
Bob Downing and Dena Konopka
MCESD (602) 506-6790

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1.3 Temporal scope
Annual and CO season-day emissions were estimated for the year 2002, for Maricopa County
and the Maricopa County CO nonattainment area (NAA). The three-month peak CO season for
Maricopa County is defined as November through January. The CO season is based on CO
exceedances from 1988 through 1991 and is consistent with the CO season in the 1990 base year
inventory.

1.4 Geographic scope
This inventory includes emission estimates for Maricopa County and for the Maricopa County
CO nonattainment area. Maricopa County encompasses approximately 9,223 square miles of
land area, while the Maricopa County CO nonattainment area is approximately 1,946 square
miles or approximately 21 percent of the Maricopa County land area. A map of Maricopa
County and the CO nonattainment area is provided in Figure 1.4–1.
Figure 1.4–1. Map of Maricopa County and the CO, ozone, and PM10 nonattainment areas.

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1.5 Overview of local demographic and land-use data
Many of the emissions estimates generated in this report were calculated using demographic and
land-use data provided by the Maricopa Association of Governments (MAG). These data were
used to apportion and/or scale Maricopa County emissions estimates to the nonattainment area
and vice versa. (For example, county-level emissions from residential natural gas usage in
Maricopa County was apportioned to the nonattainment area using the ratio of occupied households in each area). Detailed explanations of how emission estimates were apportioned or scaled
are presented in each of the following chapters, along with the data sources used.

1.5.1

Demographic data

The demographic data provided by MAG included population, housing and employment data for
calendar year 2002, for Maricopa County and the nonattainment area. Table 1.5-1 provides an
overview of the demographic data used in this report.
Table 1.5–1. Demographic profile of Maricopa County and the CO nonattainment area.
Maricopa
Within
Percent within
Demographic variable
County
CO NAA
CO NAA
Total resident population
3,296,250
3,232,387
98.06%
Total non-resident population
253,443
249,420
98.41%
Total population:
3,549,693
3,481,807
98.09%
Occupied resident housing units
Total non-resident households
Total occupied households:

1,215,173
146,664
1,361,837

1,192,680
144,419
1,337,099

98.15%
98.47%
98.18%

Retail employment
Office employment
Industrial employment
Public employment
Other employment
Total employment:

438,674
392,383
383,938
221,676
232,614
1,669,285

431,973
390,375
376,610
213,061
227,953
1,639,972

98.47%
99.49%
98.09%
96.11%
98.00%
98.24%

1.5.2

Land-use data

The most recent land-use data available from MAG was for the year 2000. The 2000 land-use
data was assumed to be representative of 2002. Table 1.5–2 presents a summary of the land-use
categories and acreage used to develop emission estimates for this inventory.

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Table 1.5–2. Land-use categories used to apportion emissions.
Acreage in
Maricopa
County
Description
Active open space (e.g., parks)
127,792
Passive open space (e.g., mountain preserves)
2,057,048
General open space (not elsewhere classified)
849
Golf courses
22,922
Water
110,940
Agriculture
415,473
Vacant (e.g., developable land)
2,653,351

Acreage
within CO
NAA
90,038
40,846
782
22,231
38,057
185,029
414,465

Percent
within CO
NAA
70.46%
1.99%
92.16%
96.98%
34.30%
44.53%
15.62%

1.6 Emissions overview by source category
1.6.1

Point sources

The point source category includes those stationary sources that emit a significant amount of
pollution into the air such as power plants and large industrial facilities. As Maricopa County
has an established annual reporting program for sources with air quality permits, the thresholds
for defining a point source are lower than the minimums required by the US EPA. For the
purposes of this inventory, a point source is a stationary operation within Maricopa County or
within 25 miles of the CO nonattainment area, which in 2002 emitted:
• 25 English (short) tons or more of carbon monoxide (CO); or
• 10 tons or more of volatile organic compounds (VOC), oxides of nitrogen (NOx), or sulfur
oxides (SOx); or
• 5 tons or more of particulate matter less than 10 microns (PM10) or ammonia compounds
(NHx).
Table 1.6–1 summarizes annual and season-day emissions of the chief point source categories.
A detailed breakdown of emissions calculations for all point sources is contained in Chapter 2.
Table 1.6–1. Summary of annual and season-day point source emissions, by source category.
Maricopa County
CO nonattainment area
Annual
Season-day
Annual
Season-day
emissions
emissions
emissions
emissions
Source category
(tons/yr)
(lbs/day)
(tons/yr)
(lbs/day)
Electricity generation
1,058.24
3,484.0
894.61
2,598.0
Commercial/institutional fuel combustion
45.63
329.7
45.63
329.9
Industrial fuel combustion
426.42
2,618.6
401.93
2,472.6
Industrial processes
82.08
565.5
82.07
565.5
Manufacturing processes
146.12
959.9
135.99
882.0
Waste disposal
64.39
343.8
56.41
299.9
All point sources:
1,822.88
8,301.5
1,616.64
7,147.9

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1.6.2

Area sources

Area sources are facilities or activities whose individual emissions do not qualify them as point
sources. Area sources represent numerous facilities or activities that individually release small
amounts of a given pollutant, but collectively they can release significant amounts of a pollutant.
Stationary sources with annual emissions lower than the point source thresholds described in
Section 1.6.1 were included in the area source inventory. Examples of area source categories
include residential wood burning, commercial cooking, waste incineration, and wildfires.
Table 1.6–2 summarizes annual and season-day emissions of the chief area source categories, for
both Maricopa County and the CO nonattainment area. A detailed breakdown of emissions
calculations for each area source category is contained in Chapter 3.
Table 1.6–2. Summary of annual and season-day area source emissions, by source category.
Maricopa County
CO nonattainment area
Annual
Season-day
Annual
Season-day
emissions
emissions
emissions
emissions
Source category
(tons/yr)
(lbs/day)
(tons/yr)
(lbs/day)
Fuel combustion
4,817.71
66,584.1
4,730.96
65,380.8
Industrial processes
412.98
2,398.4
407.74
2,369.6
Waste treatment/disposal
616.30
3,794.2
159.71
723.5
Miscellaneous area sources
2,976.99
2,537.6
243.43
1,472.8
All area sources:
8,823.98
75,314.2
5,541.86
69,946.8

1.6.3

Nonroad mobile sources

Nonroad mobile sources include off-highway vehicles and engines that move or are moved
within a 12-month period. Table 1.6–3 summarizes annual and season-day emissions from
nonroad mobile sources, for both Maricopa County and the CO nonattainment area. A detailed
breakdown of emissions calculations for each source category is contained in Chapter 4.

2002 Carbon Monoxide Periodic Emission Inventory

5

Maricopa County, AZ

Table 1.6–3. Summary of annual and season-day CO emissions from nonroad mobile sources.
Maricopa County
CO nonattainment area
Annual
Season-day
Annual
Season-day
emissions
emissions
emissions
emissions
Equipment category
(tons/yr)
(lbs/day)
(tons/yr)
(lbs/day)
Agricultural
632.96
861.9
281.86
383.8
Airport ground support equipment
3,471.09
19,071.9
3,384.31
18,595.1
Commercial
45,797.55
244,320.3
44,922.82
239,653.8
Construction & mining
15,584.58
70,666.5
15,286.91
69,316.8
Industrial
15,135.47
89,552.2
14,846.38
87,841.8
Lawn & garden
77,273.13
111,110.3
75,866.76
109,088.1
Logging
136.54
744.7
133.93
730.5
Pleasure craft
1,423.91
4,272.3
488.40
1,465.4
Railway maintenance
61.28
371.7
60.11
364.6
Recreational
9,788.20
32,092.5
987.63
3,238.1
Aircraft
10,097.03
55,478.2
9,888.43
54,332.0
Locomotives
344.35
1,886.8
160.78
881.0
All nonroad mobile sources:
179,746.09
630,429.3
166,308.32
585,891.0

1.6.4 Onroad mobile sources
Emission from onroad mobile sources were calculated for the CO nonattainment area located
primarily within Maricopa County as well as for Maricopa County as a whole. A detailed breakdown of emissions calculations by vehicle class and roadway type is contained in Chapter 5.
Tables 1.6–4 summarizes annual and season-day emissions from onroad mobile sources for both
Maricopa County and the CO nonattainment area.
Table 1.6–4. Annual and season-day emissions from onroad mobile sources in Maricopa County.
Annual emissions
Season-day
(tons/yr)
emissions (lbs/day)
Geographic area
Maricopa County
352,821
1,925,867
CO NAA
322,867
1,763,151

1.6.5

Summary of emissions by source category

Figures 1.6–1 and 1.6–2 provide a graphical overview of the relative contributions of the major
source categories (point, area, nonroad, and onroad) to CO emissions in the nonattainment area,
on an annual and season-day basis, respectively.

2002 Carbon Monoxide Periodic Emission Inventory

6

Maricopa County, AZ

Figure 1.6–1. Annual emissions in the CO nonattainment area, by source category (tons/yr).

Area:
5,541.9
(1%)

Points:
1,616.6
(< 1%)

Nonroad:
166,308.3
(34%)

Onroad:
322,867.0
(65%)

Figure 1.6–2. Season-day emissions in the CO nonattainment area, by source category (lbs/day).

Area:
69,947
(3%)

Points:
7,148
(< 1%)

Nonroad:
585,891
(24%)

Onroad:
1,763,151
(73%)

2002 Carbon Monoxide Periodic Emission Inventory

7

Maricopa County, AZ

Tables 1.6–5 and 1.6–6 provides a comparison between this inventory and earlier periodic CO
emissions inventories for the CO nonattainment area. Note that figures may not be directly
comparable as calculation methods, emission factors, and source category definitions (e.g., point
vs. area sources) may have changed over time.

Table 1.6–5. Summary of annual CO emissions (tons/yr) in the CO nonattainment area, by source category,
1990–2002.
Inventory year
Source category
1990
1993
1996
1999
2002
Points
1,299
874
665
1,753
1,617
Area
13,338
14,231
3,730
5,840
5,542
Nonroad mobile
167,303
166,335
184,220
195,042
166,308
Onroad mobile*
n/a
n/a
n/a
n/a
322,867
173,467 **
Total
181,940
181,440
188,615
202,635
* Prior-year inventories did not include annual totals of onroad mobile emissions.
** Total does not include onroad mobile sources, to allow more direct comparison to prior-year inventories.

Table 1.6–6. Summary of CO season-day emissions (lbs/day) in the CO nonattainment area, by source
category, 1990–2002.
Inventory year
Source category
1990
1993
1996
1999
2002
Points
17,400
14,800
12,600
18,180
7,148
Area
175,400
186,600
42,000
48,120
69,947
Nonroad mobile
476,000
460,000
904,000
1,147,900
585,891
Onroad mobile
1,615,410
1,220,223
1,120,508
1,080,829
1,763,151
Total
2,284,210
1,881,623
2,079,108
2,295,029
2,426,137

1.7 References
ENVIRON et al., 2003. Maricopa County 2002 Comprehensive Emission Inventory for the Cap
and Trade Oversight Committee, Final Rep. prepared for Arizona Dept. of Environmental
Quality, October 9, 2003.

2002 Carbon Monoxide Periodic Emission Inventory

8

Maricopa County, AZ

2.

Point Sources

2.1

Introduction and scope

This carbon monoxide (CO) inventory is one of a number of emission inventory reports being
prepared to meet US EPA reporting requirements. In addition to preparing periodic emissions
inventories for the CO nonattainment area (NAA) as a commitment under the current CO State
Implementation Plan (SIP), the federal Consolidated Emission Reporting Rule (CERR) requires
that state and local agencies prepare emissions estimates on a county basis, and submit data
electronically to the US EPA for inclusion in the National Emission Inventory (NEI) for 2002.
This CO inventory is being developed concurrently with similar inventories for ozone precursors
(VOC, NOx and CO), and PM (including PM10, PM2.5, NOx, SOx, and NH3), as part of Maricopa
County's requirements under the respective SIPs.
In order to provide consistency among all these inventories, it was decided to standardize the
definition of a “point source”. While the US EPA has defined minimum point source reporting
thresholds for various pollutants, EPA guidance also notes that:
… we encourage organizations to provide facility-specific emissions data for all point sources, regardless of size, where they are
already included in the S/L/T [state/local/tribal] emission inventory. (US EPA, 2003)
As Maricopa County has an established annual reporting program for sources with air quality
permits, the thresholds for defining a point source are lower than the minimums required by
EPA. For the purposes of this inventory, a point source is a stationary operation within Maricopa
County or within 25 miles of the CO nonattainment area, which in 2002 emitted:
• 25 English (short) tons or more of carbon monoxide (CO); or
• 10 tons or more of volatile organic compounds (VOC), oxides of nitrogen (NOx), or
sulfur oxides (SOx); or
• 5 tons or more of particulate matter less than 10 microns (PM10) or ammonia compounds
(NHx).
While the above approach results in some anomalies (e.g., a facility treated as a point source may
have very low, or no, emissions of a certain pollutant), a uniform definition of “point source”
ensures that all data sets, which are prepared for a variety of purposes, will be comparable.
This point source inventory includes actual CO emissions for the year 2002 and a typical day
during the CO season (defined as November through January). A description and map of the
nonattainment area are provided in Chapter 1. Questions concerning point source emissions may
be directed to Bob Downing of MCESD at (602) 506-6790.
Several tables have been constructed to provide the point source emissions and category totals.
Table 2.2–1 summarizes all point sources by location and permitting authority. Table 2.2–2
provides an alphabetical list of all point sources and their location, while Table 2.3–1 shows the
2002 annual and average CO season-day emissions broken out by facility. Table 2.5–1 lists the
2002 annual and CO season-day emissions broken out by individual process types, and Table

2002 Carbon Monoxide Periodic Emission Inventory

9

Maricopa County, AZ

2.6–1 summarizes point source CO emissions by source category. Note that totals shown in all
tables may not equal the sum of individual values due to independent rounding.

2.2

Identification of CO point sources

Maricopa County Environmental Services Department (MCESD) identified point sources within
Maricopa County through its permit system database and the 2002 annual emissions reports
submitted to the department. In addition, the permit system was reviewed to locate new facilities
that were not included in the previous emission inventory, and to identify sources that have
ceased operations since the 1999 periodic inventory was compiled.
A total of 172 point sources were identified using the emission thresholds described in Section
2.1. Of the 172 stationary point sources, 111 MCSED-permitted sources reported some level of
CO emissions – 97 within the CO nonattainment area, and 14 outside the CO NAA. There are 2
additional point sources (Hexcel Corp. and SRP Desert Basin Generating Station) within the 25mile boundary around the CO nonattainment area, with permits issued by the Pinal County Air
Quality Control District (PCAQCD). While the Arizona Department of Environmental Quality
(ADEQ) retains permitting authority for a limited number of industrial source categories in
Maricopa County, no ADEQ-permitted facilities are considered point sources, and are addressed
instead as area sources.
Table 2.2–1. Number of stationary point sources by location and permitting authority.
Total no. of Facilities reporting
Location
facilities
CO emissions
Within the CO nonattainment area:
– Maricopa County-permitted sites
153
97
Outside the CO nonattainment area:
– Maricopa County-permitted sites
– Pinal County-permitted sites
Total outside NAA:
Grand total:

17
2
19
172

14
2
16
113

Table 2.2–2 contains an alphabetical list of all point sources, including a unique business identification number, NAICS industry classification code, business name (including any changes
from the 1999 periodic inventory), and physical address.
Table 2.2–2. Name and location of all point sources.
Within the CO nonattainment area:
ID # NAICS Business name
1074 22132 23rd Ave. Wastewater Treatment Plant
(formerly City of Phoenix 23rd Ave. WWTP)
1075 22132 91st Ave. Wastewater Treatment Plant
245 337122 A. F. Lorts Company Inc.
1952 811121 Adesa Phoenix LLC
1239 332321 AG Products
35541 33121 Allied Tube & Conduit Corp.
199 327332 Ameron Intl. Water Transmission Group
(formerly Ameron Pipe)

2002 Carbon Monoxide Periodic Emission Inventory

10

Address
2470 S. 22nd Ave.

City
Phoenix

ZIP
85009

5615 S. 91st Ave.
8120 W. Harrison St.
400 N. Beck Ave.
2525 W. Broadway Rd..
2525 N. 27th Ave.
2325 S. 7th St.

Tolleson
Tolleson
Chandler
Phoenix
Phoenix
Phoenix

85353
85353
85226
85041
85009
85034

Maricopa County, AZ

Table 2.2–2. Name and location of point sources (continued).
ID # NAICS Business name
292 325412 Anabolic Laboratories Inc.
(formerly Health Factors International Inc.)
3313 221112 APS West Phoenix Power Plant
3938 332812 Arizona Galvanizing Inc.
4364 61131 Arizona State University
36485 54185 Billboard Poster Company Inc.
43124 313230 Bonded Logic Inc.
3441 42471 BP West Coast Products LLC
458 32191 Bryant Industries Inc.
217 327123 Building Products Co.
3442 493190 Caljet (formerly Caljet/Williams)
60598 337211 Case Furniture & Design LLC
1317 321991 Cavco Industries LLC (35th Ave.)
1318 321991 Cavco Industries LLC (Litchfield Rd.)
1316 321991 Cavco Industries LLC (Durango Plant)
4145 61111 Cave Creek School District
1267 32732 Cemex Mesa Plants #61 & #71
1266 212321 Cemex USA (Phoenix)
1268 212321 Cemex USA (Sun City)
1310 32311 Century Graphics LLC
1426 32311 Cesar Color Inc.
4401 32732 Chandler Ready Mix Inc.
51073 52312 Charles Schwab & Co. Inc.
3297 42471 Chevron USA Inc.
3976 33711 Cholla Custom Cabinets Inc.
4083 32191 Chris Fischer Productions Inc.
399 32739 Coreslab Structures (Ariz) Inc.
1198 32311 Courier Graphics Corp.
4368 32191 Craftsmen in Wood Mfg.
4023 321918 Creative Shutters Inc.
3744 325991 Desert Sun Fiberglass
130 331512 Dolphin Inc.
508 337122 Eagle Industries LLC (formerly Samuel
Lawrence Furniture Co.)
45493 811121 Earnhardt Ford
3305 311812 Earthgrains Baking Companies Inc.
26 423810 Empire Machinery Co.
1505 32191 Executive Door
544 321991 Fleetwood Homes of Arizona Inc. #21
27728 334413 FlipChip International LLC (formerly Flip
Chip Technologies)
41751 326121 GCR Truck Tire Center
4050 311812 General Mills (formerly Pillsbury Bakeries &
Food Service)
4173 562212 Glendale Municipal Sanitary Landfill
781 62211 Good Samaritan Regional Medical Ctr.
1418 326299 Goodrich Aircraft Interior Products (formerly
BF Goodrich Aircraft Evacuation Sys.)
36772 212321 GTI Capital Holdings LLC
699 212321 Hanson Aggregates of Arizona (Phoenix)
31565 32614 Henry Products Inc.
529 32614 Highland Products Inc.
4543 32311 Hogue Printing Inc.
3536 311812 Holsum Bakery Inc.

2002 Carbon Monoxide Periodic Emission Inventory

11

Address
429 S. Siesta Ln.

City
Tempe

ZIP
85281

4606 W. Hadley St.
15775 Elwood St.
1551 S. Rural Rd.
3940 W. Montecito Ave.
411 E. Ray Rd.
5333 W. Van Buren St.
788 W. Illini St.
4850 W. Buckeye Rd
125 N. 53rd Ave.
4645 W. Polk St.
2602 S. 35th Ave.
1366 S. Litchfield Rd.
2502 W. Durango St.
33606 N. 60th St.
1901 N. Alma School Rd.
11701 W. Indian School
24004 N. 107th Ave.
2960 Grand Ave.
3433 E. Wood St.
6500 N. 115th Ave.
2121 S. Price Rd.
5110 W. Madison St.
1727 E. Deer Valley Dr.
4741 W. Polk St.
5026 S. 43rd Ave.
2621 S. 37th St.
5441 W. Hadley St.
2009 W. Ironwood Dr.
21412 N. 14th Ave.
740 S. 59th Ave.
601 S. 65th Ave.

Phoenix
Goodyear
Tempe
Phoenix
Chandler
Phoenix
Phoenix
Phoenix
Phoenix
Phoenix
Phoenix
Goodyear
Phoenix
Cave Creek
Mesa
Phoenix
Sun City
Phoenix
Phoenix
Glendale
Chandler
Phoenix
Phoenix
Phoenix
Phoenix
Phoenix
Phoenix
Phoenix
Phoenix
Phoenix
Phoenix

85043
85338
85287
85019
85225
85043
85041
85043
85043
85043
85009
85338
85009
85331
85201
85063
85373
85017
85040
85323
85248
85043
85024
85043
85041
85034
85043
85021
85027
85043
85043

7300 W. Orchid Ln.
738 W. Van Buren St.
1725 S. Country Club Dr.
3939 W. Clarendon Ave.
6112 N. 56th Ave.
3701 E. University Dr.

Chandler
Phoenix
Mesa
Phoenix
Glendale
Phoenix

85226
85007
85210
85019
85311
85034

2815 N. 32nd Ave.
1120 W. Fairmont Dr.

Phoenix
Tempe

85009
85282

11480 W. Glendale Ave.
1111 E. McDowell Rd.
3414 S. 5th St.

Glendale
Phoenix
Phoenix

85301
85006
85040

3636 S. 43rd Ave.
4002 S. 51st Ave.
302 S. 23rd Ave.
43 N. 48th Ave.
159 W. 1st Ave.
2322 W. Lincoln St.

Phoenix
Phoenix
Phoenix
Phoenix
Mesa
Phoenix

85009
85043
85009
85043
85210
85009

Maricopa County, AZ

Table 2.2–2. Name and location of point sources (continued).
ID # NAICS Business name
3802 311812 Holsum Bakery Tempe
1059 336412 Honeywell Engines Systems & Service
(formerly Honeywell Aerospace Services)
355 336412 Honeywell International Inc.
354 331314 Imsamet of Arizona
777 32614 Insulfoam
3966 334413 Intel Corp. Ocotillo Campus (Fab 12 & 22)
(formerly Intel Corp. Ocotillo Campus Fab 12)
983 334419 Isola Laminate Systems Corp.
3317 221112 Kyrene Generating Station (formerly SRP
Kyrene Steam Plant)
341 325991 L & M Laminates & Marble
4182 337122 Legends Furniture Inc.
857 334412 Litton Electro-Optical Systems
3300 92811 Luke Air Force Base
744
3325 M. E. Global Inc.
(formerly M. E. West Castings Inc.)
1248 325991 Maax Spas
31261 21231 Madison Granite Supplies
4111 337121 Magic Woods Inc.
205 322232 Mail-Well Envelope
353 326199 Marlam Industries Inc.
61268 327390 Master Block Inc.
62 33711 Mastercraft Cabinets Inc.
3326 352991 Mesa Fully Formed Inc.
1414 212321 Mesa Materials Inc. (Mesa)
1415 212321 Mesa Materials Inc. (Phoenix)
29474 423930 Metal Management Arizona Inc.
1203 334413 Microchip Technology Inc. (Chandler)
1875 334413 Microchip Technology Inc. (Tempe)
226 32739 Monier Lifetile LLC
882 311942 Morton Salt Glendale Facility
881 334413 Motorola Inc.
223 333112 MTD Southwest Inc.
693 333415 Munters Corp.
34197 327420 National Gypsum Co.
948 32614 Nesco Manufacturing Inc.
1309 337122 New Directions Inc.
1331 337122 Oak Canyon Manufacturing Inc.
(formerly Aspen II)
3953 33711 Oakcraft Inc.
27925 337122 Oasis Bedroom Co.
52382 221112 Ocotillo Power Plant
3982 32311 O'Neil Printing Inc.
3970 337122 Pacific Designs
1344 321991 Palm Harbor Homes Inc.
733 811412 Pan-Glo West
419 336412 Parker Hannifin GTFSD
1341 33992 Penn Racquet Sports Inc.
1014 327121 Phoenix Brick Yard
562 51111 Phoenix Newspapers Inc.
148 331528 Presto Casting Co.
60889 326212 Purcell’s Western States Tire
1030 32311 Quebecor World Phoenix Division

2002 Carbon Monoxide Periodic Emission Inventory

12

Address
710 W. Geneva Dr.
1944 E. Sky Harbor Cir.

City
Tempe
Phoenix

ZIP
85252
85034

111 S. 34th St.
3829 S. Estrella Pkwy.
3401 W. Cocopah St.
4500 S. Dobson Rd.

Phoenix
Goodyear
Phoenix
Chandler

85034
85338
85009
85248

165 S. Price Rd.
7005 S. Kyrene Rd.

Chandler
Tempe

85224
85283

813 E. University Dr.
5555 N. 51st Ave.
1215 S. 52nd St.
14002 W. Marauder St.
5857 S. Kyrene Rd.

Phoenix
Glendale
Tempe
Glendale
Tempe

85034
85301
85281
85309
85283

25605 S. Arizona Ave.
30600 N. 23rd Ave.
4210 N. 39th Ave.
221 N. 48th Ave.
834 E. Hammond Ln.
12620 W. Butler Dr.
305 S. Brooks
1111 S. Sirrine St.
3410 N. Higley Rd.
7845 W. Broadway Rd.
3640 S. 35th Ave.
2355 W. Chandler Blvd.
1200 S. 52nd St.
1832 S. 51st Ave.
13000 W. Glendale Ave.
1300 N. Alma School Rd.
550 N. 54th St.
802 S. 59th Ave.
1414 E. Hadley St.
1510 W. Drake Dr.
2940 W. Willetta St.
3021 N. 29th Dr.

Chandler
Phoenix
Phoenix
Phoenix
Phoenix
El Mirage
Mesa
Mesa
Mesa
Phoenix
Phoenix
Chandler
Tempe
Phoenix
Glendale
Chandler
Chandler
Phoenix
Phoenix
Tempe
Phoenix
Phoenix

85248
85027
85019
85043
85034
85335
85202
85210
85205
85043
85009
85224
85281
85043
85307
85224
85226
85043
85034
85283
85009
85017

7733 W. Olive Ave.
2022 N. 22nd Ave.
1500 E. University Dr.
366 N. 2nd Ave.
2425 W. Sherman St.
309 S. Perry Ln.
2401 W. Sherman St.
7777 N. Glen Harbor Bd.
306 S. 45th Ave.
1814 S. 7th Ave.
22600 N. 19th Ave.
5440 W. Missouri Ave.
420 S. 35th Ave.
1850 E. Watkins St.

Peoria
Phoenix
Tempe
Phoenix
Phoenix
Tempe
Phoenix
Glendale
Phoenix
Phoenix
Phoenix
Glendale
Phoenix
Phoenix

85345
85009
85281
85003
85043
85281
85009
85307
85043
85007
85027
85301
85009
85034

Maricopa County, AZ

Table 2.2–2. Name and location of point sources (continued).
ID # NAICS Business name
537 327999 Red Mountain Mining Inc.
1503 321991 Redman Homes Inc.
303 332431 Rexam Beverage Can Company
4318 32732 River Ranch Plant
759 32613 Rogers Corp. Advanced Circuit Materials
1437 334412 Sanmina Phoenix Division (formerly
Hadco Phoenix Inc./Sanmina Phx. Div.)
3315 221112 Santan Generating Station
(formerly Santan Generating Plant)
266 332312 Schuff Steel Co.
42636 62211 Scottsdale Health Care Hospital
4175 493190 SFPP LP
70634 42471 Shell Oil Phoenix Terminal
(formerly Texaco Phoenix Terminal)
27933 562212 Skunk Creek Landfill
4471 332311 Skyline Steel Inc.
31627 115111 South Mountain Gin
3316 221112 SRP Agua Fria
4131 334413 ST Microelectronics
1444 327123 Staco Architectural Roof Tile
582 337122 Stone Creek Inc.
281 212321 Sun State Rock & Materials
101 31161 Sunland Beef Co.
52471 325188 Superior Lime & Chemical
3978 337122 Team Two Design Assoc Inc.
249 336411 The Boeing Company
937 336211 The Heil Company
232 72111 The Phoenician Resort
1102 325412 The Procter & Gamble Mfg Co.
552 337122 Thornwood Furniture Mfg.
363 337122 Thunderbird Furniture
56 32739 TPAC Division of Kiewit Western Co.
1210 337122 Trendwood Inc. (15th Ave.)
1211 337122 Trendwood Inc. (University Dr.)
819 336399 TRW Vehicle Safety Systems Inc.
169 811111 U Haul Intl. Technical Center
1228 325991 Ultra Installations Inc.
234 311514 United Dairymen of Arizona
260 212321 United Metro Plant #11
213 212321 United Metro Plant #12
403 331316 VAW of America
2 32412 Vulcan Materials Co. (El Mirage)
90 32732 Vulcan Materials Co. (Phoenix)
174 325998 W. R. Meadows of Arizona Inc.
141 424910 Western Organics Inc.
4384 321918 Western Shutter LLC
2703 42471 Western States Petroleum
20706 32614 Wincup Holdings Inc.
1382 33711 Woodcase Fine Cabinetry Inc.
(formerly McCarthy Cabinet Co.)
72 337122 Woodstuff Manufacturing Inc.

2002 Carbon Monoxide Periodic Emission Inventory

13

Address
4250 N. Bush Hwy.
400 E. Ray Rd.
211 N. 51st Ave.
5159 N. El Mirage Rd.
100 S. Roosevelt Ave.
5020 S. 36th St.

City
Mesa
Chandler
Phoenix
Litchfield Pk
Chandler
Phoenix

ZIP
85215
85225
85043
85340
85226
85040

1005 S. Val Vista Rd.

Gilbert

85296

420 S. 19th Ave.
7400 E. Osborn Rd.
49 N. 53rd Ave.
5325 W. Van Buren St.

Phoenix
Scottsdale
Phoenix
Phoenix

85009
85251
85043
85043

3165 W. Happy Valley Rd
631 W. Commerce Ave.
6411 S. 51st Ave.
7302 W. Northern Ave.
1000 E. Bell Rd.
3530 E. Elwood St.
4221 E. Raymond St.
11500 W. Beardsley Rd.
651 S. 91st Ave.
320 S. 27th Ave.
310 S. 43rd Ave.
5000 E. McDowell Rd.
1500 S. 7th St.
6000 E. Camelback Rd.
2050 S. 35th Ave.
5125 E. Madison St.
7501 E. Redfield Rd.
3052 S. 19th Ave.
2402 S. 15th Ave.
261 E. University Dr.
11202 E. Germann Rd.
11298 S. Priest Dr.
245 S. Mulberry
2008 S. Hardy Dr.
3640 S. 19th Ave.
11920 W. Glendale Ave.
249 S. 51st Ave.
14521 N. 115th Ave.
4830 S. 43rd Ave.
2636 S. Sarival Ave.
2807 S. 27th Ave.
4038 E. Madison St.
450 S. 15th Ave.
7980 W. Buckeye Rd.
3255 W. Osborn Rd.

Phoenix
Gilbert
Laveen
Glendale
Phoenix
Phoenix
Phoenix
Sun City
Tolleson
Phoenix
Phoenix
Mesa
Phoenix
Scottsdale
Phoenix
Phoenix
Scottsdale
Phoenix
Phoenix
Phoenix
Queen Creek
Tempe
Mesa
Tempe
Phoenix
Glendale
Phoenix
El Mirage
Phoenix
Goodyear
Phoenix
Phoenix
Phoenix
Phoenix
Phoenix

85027
85233
85339
85303
85022
85040
85040
85373
85353
85009
85009
85215
85034
85251
85009
85034
85260
85009
85007
85004
85242
85284
85202
85282
85009
85307
85043
85335
85041
85338
85009
85034
85007
85043
85017

1635 S. 43rd Ave.

Phoenix

85009

Maricopa County, AZ

Table 2.2–2. Name and location of point sources (continued).
The following point sources are outside the CO nonattainment area:
ID # NAICS Business name
Address
31606 115111 Acme Gin Co. Inc.
7401 S. Wilson Rd.
1874 212321 Alleco Stone LLC
10401 S. Miller Rd.
31643 562212 Allied Waste Industries Inc.
24427 S. Hwy 85
31637 115111 Anderson Clayton Corp. Valencia Gin
25500 W. Southern Ave.
1218 562212 Butterfield Station
40404 S. 99th Ave.
1389 541380 DaimlerChrysler AZ Proving Grounds
33040 N. 203rd Ave.
43063 221112 Duke Energy Arlington Valley LLC
39027 W. Elliot Rd.
1488 115111 Farmers Gin Inc.
8400 S. Turner St.
10211
Hexcel Corp. †
1214 W. Gila Bend Hwy.
725 212321 Kilauea Crushers Inc.
Hwy 74
1879 562212 Northwest Regional Landfill
19401 W. Deer Valley Rd
98 221113 Palo Verde Nuclear Generating Station
5801 S. Wintersburg Rd.
428 115111 Paloma Gin Properties LLC
I-8
289 115111 Phoenix Agro Invest Inc.
51040 W. Valley Rd.
42956 221112 Pinnacle West Energy Corp.
11600 S. 363rd Ave.
44182 332312 Quincy Joist Company
22253 W. Southern Ave.
246 321991 Schult Homes
231 N. Apache Rd.
10469 221112 SRP Desert Basin Generating Station †
1872 N. Burris Rd.
398 212321 Wickenburg Facility
44605 Grand Ave.
† Source is located in Pinal County.

2.3

City
Buckeye
Buckeye
Buckeye
Buckeye
Mobile
Wittmann
Arlington
Buckeye
Casa Grande
Wickenburg
Surprise
Tonopah
GilaBend
Aguila
Arlington
Buckeye
Buckeye
Casa Grande
Wickenburg

ZIP
85326
85326
85326
85326
85239
85361
85322
85326
85222
85358
85374
85354
85337
85320
85322
85326
85326
85222
85390

Procedures for estimating emissions from point sources

Both annual and average season-day CO emissions were estimated from annual source emission
reports, MCESD investigation reports, permit files and logs, or telephone contacts with sources.
For most of the sources, material balance methods were used for determining emissions.
Emissions were estimated using the emission factors from AP–42, source tests, engineering
calculations, or manufacturers' specifications.
MCESD distributes annual emissions survey forms to nearly all facilities for which MCESD has
issued an operating permit. Facilities are required to report detailed information on stacks,
control devices, operating schedules, and process-level information concerning their annual
activities. (See Appendix 2.1 for a copy of the instructions to complete the emissions inventory.)
These instructions include examples and explanations on how to complete the annual emissions
reporting forms that facilities must submit to MCESD. Activity data reported for the December–
February winter season is presumed to be representative of the November–January CO season.
After a facility has submitted an annual emissions report to MCESD, emissions inventory staff
check all reports for missing and questionable data, and check the accuracy and reasonableness
of all emissions calculations with AP–42, the Factor Information and REtrieval (FIRE) software,
and other EPA documentation. Control efficiencies are determined by source tests when available, or by AP–42 factors, engineering calculations, or manufacturers' specifications. MCESD
has conducted annual emissions surveys for permitted facilities since 1988, and the department's
database system, EMS, contains numerous automated quality assurance/quality control checks
for data input and processing.

2002 Carbon Monoxide Periodic Emission Inventory

14

Maricopa County, AZ

2.3.1

Example 1: Ocotillo Power Plant

General Facility Information: Arizona Public Service (APS) operates a peaking electric
generating plant with two steam units (gas/oil-fired boilers) and two natural-gas turbines. APS
provided its total annual fuel consumption for each unit, as well as daily and seasonal operating
activity. Total annual emissions from boilers and turbines are summed to obtain the facility's
total annual CO emissions. The Ocotillo power plant provided the following information. The
following data were used to calculate emissions from boilers and turbines:
SCC
10100604
20100201

Source type
Natural gas boilers
Natural gas turbines

Annual fuel
consumption
3,406.56 MMCF
673.59 MMCF

CO emission
factor
24 lb/ MMCF
83.64 lb/ MMCF

CO emissions
(lbs/yr)
81,757.0
56,339.0

Calculation of annual CO emissions:
Annual emissions (lbs) = Annual fuel consumption × emission factor
CO emissions from natural-gas boilers

= 3,406.56 MMCF × 24 lb CO/MMCF
= 81,757 lbs CO/yr

CO emissions from natural-gas turbines = 673.59 MMCF × 83.64 lb CO/MMCF
= 56,339 lbs CO/yr
Total CO emissions = 81,757 lbs + 56,339 lbs
= 138,096 lbs/yr
= 69.05 tons CO/yr

Calculation of CO season-day emissions:
APS provided seasonal operating data for each boiler and turbine. The activity reported for the
December–February time period ranged from 14 to 37 percent among all natural-gas fired
equipment. The average season-day emissions were calculated individually, as illustrated in the
following example for Steam Unit No. 1 burning natural gas:
CO season-day emissions = annual emissions × seasonal activity factor ÷ (days/week × weeks/season)
= 50,986 lb CO
× 19%
÷ (7 days/wk × 13 wks/season)
= 106.5 lbs CO/season day

The daily calculations for each boiler and turbine were then summed to derive total CO seasonday emissions.
2.3.2

Example 2: Imsamet of Arizona

General Facility Information: This secondary foundry facility has two electric arc furnaces
(EAFs) and two heat treat furnaces. Carbon monoxide emissions of 21.5 lbs/hr of operation
were calculated from stack tests conducted on the electric arc furnaces in 1999. Seasonal activity
levels for each process are also reported annually.
Calculation of annual CO emissions:
Annual emissions (lbs) = Total hours of operation × emission factor
= 7,503 hrs/yr × 21.5 lb CO/hr
= 161,315 lbs CO/yr = 80.66 tons CO/yr
2002 Carbon Monoxide Periodic Emission Inventory

15

Maricopa County, AZ

Calculation of CO season-day emissions:
CO season-day emissions = Annual emissions × seasonal activity factor ÷ (days/week × weeks/season)
= 161,315 lbs/yr
× 26%
÷ ( 7 days/wk × 13 wks/season)
= 460.9 lbs CO/day

Table 2.3–1 provides a list of annual and season-day CO emissions from those point sources that
reported CO emissions, broken out by location (inside or outside the CO nonattainment area).
Table 2.3–1. Annual and CO season-day point source emissions, by facility.
Facilities within the CO nonattainment area:
Annual CO
Season-day CO
emissions (tons/yr) emissions (lbs/day)
ID # Business name
City
1074 23rd Ave. Wastewater Treatment Plant
Phoenix
50.91
258.7
1075 91st Ave. Wastewater Treatment Plant
Tolleson
4.03
43.0
245 A F Lorts Company Inc.
Tolleson
0.01
0.1
1952 Adesa Phoenix LLC
Chandler
0.01
0.0
35541 Allied Tube & Conduit Corp.
Phoenix
0.33
1.9
199 Ameron Intl. Water Transmission Group
Phoenix
0.53
11.0
292 Anabolic Laboratories Inc.
Tempe
0.12
0.9
3313 APS West Phoenix Power Plant
Phoenix
116.58
429.6
3938 Arizona Galvanizing Inc.
Goodyear
2.98
17.8
4364 Arizona State University
Tempe
15.14
138.7
43124 Bonded Logic Inc.
Chandler
0.16
1.3
217 Building Products Co.
Phoenix
16.73
92.3
3442 Caljet
Phoenix
4.30
23.6
4145 Cave Creek School District
Cave Creek
3.21
24.8
1267 Cemex Mesa Plants #61 & #71
Mesa
2.14
10.4
1310 Century Graphics LLC
Phoenix
0.04
0.3
1426 Cesar Color Inc.
Phoenix
0.41
3.1
51073 Charles Schwab & Co. Inc.
Chandler
0.92
5.0
3976 Cholla Custom Cabinets Inc.
Phoenix
0.01
0.1
1198 Courier Graphics Corp.
Phoenix
0.20
1.4
4368 Craftsmen in Wood Mfg.
Phoenix
0.06
0.5
130 Dolphin Inc.
Phoenix
1.71
12.1
508 Eagle Industries LLC
Phoenix
0.02
0.2
3305 Earthgrains Baking Companies Inc.
Phoenix
1.53
9.8
26 Empire Machinery Co.
Mesa
21.16
110.6
27728 FlipChip International LLC
Phoenix
0.28
1.5
4050 General Mills
Tempe
0.67
4.1
4173 Glendale Municipal Sanitary Landfill
Glendale
1.67
12.9
781 Good Samaritan Regional Medical Ctr.
Phoenix
8.24
31.5
1418 Goodrich Aircraft Interior Products
Phoenix
1.51
15.4
31565 Henry Products Inc.
Phoenix
0.49
3.0
529 Highland Products Inc.
Phoenix
1.15
9.2
3536 Holsum Bakery Inc.
Phoenix
2.77
21.3
3802 Holsum Bakery Tempe
Tempe
0.89
7.1
1059 Honeywell Engines Systems & Service
Phoenix
1.99
18.2
355 Honeywell International Inc.
Phoenix
20.13
110.6
354 Imsamet of Arizona
Goodyear
80.66
460.9
777 Insulfoam
Phoenix
0.94
6.0
3966 Intel Corp. Ocotillo Campus (Fab 12 & 22)
Chandler
14.69
118.9
983 Isola Laminate Systems Corp.
Chandler
9.14
58.6
3317 Kyrene Generating Station
Tempe
39.17
18.7

2002 Carbon Monoxide Periodic Emission Inventory

16

Maricopa County, AZ

Table 2.3–1. Annual and CO season-day point source emissions, by facility (continued).
Annual CO
Season-day CO
emissions (tons/yr) emissions (lbs/day)
ID # Business name
City
3300 Luke Air Force Base
Glendale
10.75
86.0
744 M. E. Global Inc.
Tempe
56.22
427.1
31261 Madison Granite Supplies
Phoenix
14.59
112.3
205 Mail-Well Envelope
Phoenix
0.71
3.6
353 Marlam Industries Inc.
Phoenix
0.02
0.2
61268 Master Block Inc.
El Mirage
0.22
1.4
62 Mastercraft Cabinets Inc.
Mesa
0.13
1.6
1414 Mesa Materials Inc. (Mesa)
Mesa
16.28
75.1
1415 Mesa Materials Inc. (Phoenix)
Phoenix
11.22
51.8
29474 Metal Management Arizona Inc.
Phoenix
0.16
1.0
1203 Microchip Technology Inc.
Chandler
1.94
10.9
1875 Microchip Technology Inc.
Tempe
3.60
20.6
226 Monier Lifetile LLC
Phoenix
0.79
5.0
882 Morton Salt Glendale Facility
Glendale
3.82
29.4
881 Motorola Inc.
Chandler
1.85
24.4
223 MTD Southwest Inc.
Chandler
46.12
355.7
693 Munters Corp.
Phoenix
0.15
1.1
34197 National Gypsum Co.
Phoenix
16.15
103.9
3953 Oakcraft Inc.
Peoria
0.07
0.5
52382 Ocotillo Power Plant
Tempe
69.05
343.9
733 Pan-Glo West
Phoenix
0.63
4.8
1341 Penn Racquet Sports Inc.
Phoenix
3.88
30.6
1014 Phoenix Brick Yard
Phoenix
34.27
188.3
562 Phoenix Newspapers Inc.
Phoenix
0.27
3.9
148 Presto Casting Co.
Glendale
0.95
7.3
60889 Purcell's Western States Tire
Phoenix
0.15
1.2
1030 Quebecor World Phoenix Division
Phoenix
39.99
328.1
537 Red Mountain Mining Inc.
Mesa
1.43
11.0
303 Rexam Beverage Can Company
Phoenix
4.29
23.6
759 Rogers Corp. Advanced Circuit Materials
Chandler
35.74
194.3
1437 Sanmina Phoenix Division
Phoenix
1.53
9.8
3315 Santan Generating Station
Gilbert
339.66
1,042.9
266 Schuff Steel Co.
Phoenix
0.74
4.7
42636 Scottsdale Health Care Hospital
Scottsdale
1.38
10.5
4175 SFPP LP
Phoenix
8.96
49.2
70634 Shell Oil Phoenix Terminal
Phoenix
0.28
1.6
27933 Skunk Creek Landfill
Phoenix
0.59
3.2
31627 South Mountain Gin
Laveen
0.12
1.6
3316 SRP Agua Fria
Glendale
330.15
762.9
4131 ST Microelectronics
Phoenix
4.46
24.5
1444 Staco Architectural Roof Tile
Phoenix
0.05
0.5
281 Sun State Rock & Materials
Sun City
0.73
4.7
101 Sunland Beef Co.
Tolleson
10.21
60.1
249 The Boeing Company
Mesa
1.50
11.5
232 The Phoenician Resort
Scottsdale
9.98
52.8
1102 The Procter & Gamble Mfg Co.
Phoenix
0.70
5.4
56 TPAC Division of Kiewit Western Co.
Phoenix
0.80
6.2
819 TRW Vehicle Safety Systems Inc.
QueenCreek
3.18
20.0
234 United Dairymen of Arizona
Tempe
27.51
157.1
260 United Metro Plant #11
Phoenix
16.52
65.0
213 United Metro Plant #12
Glendale
30.45
171.9
403 VAW of America Inc.
Phoenix
10.65
68.3
2 Vulcan Materials Co. (El Mirage)
El Mirage
2.03
10.4

2002 Carbon Monoxide Periodic Emission Inventory

17

Maricopa County, AZ

Table 2.3–1. Annual and CO season-day point source emissions, by facility (continued).
Annual CO
Season-day CO
emissions (tons/yr) emissions (lbs/day)
ID # Business name
City
174 W. R. Meadows of AZ Inc.
Goodyear
0.16
2.0
20706 Wincup Holdings Inc.
Phoenix
11.19
56.6
72 Woodstuff Manufacturing Inc.
Phoenix
0.07
0.5
CO nonattainment area totals:
1,616.64
7,147.9
Facilities outside the CO nonattainment area:
31606 Acme Gin Co. Inc.
1874 Alleco Stone LLC
31643 Allied Waste Industries Inc.
31637 Anderson Clayton Corp. Valencia Gin
1218 Butterfield Station
1389 DaimlerChrysler AZ Proving Grounds
43063 Duke Energy Arlington Valley LLC
1488 Farmers Gin Inc.
10211 Hexcel Corp.
1879 Northwest Regional Landfill
98 Palo Verde Nuclear Generating Station
428 Paloma Gin Properties LLC
289 Phoenix Agro Invest Inc.
42956 Pinnacle West Energy Corp.
10469 SRP Desert Basin Generating Station
398 Wickenburg Facility
Total, outside the NAA:
Grand total:

2.4

Buckeye
Buckeye
Buckeye
Buckeye
Mobile
Wittmann
Arlington
Buckeye
Casa Grande
Surprise
Tonopah
Gila Bend
Aguila
Arlington
Casa Grande
Wickenburg

0.02
3.89
0.90
0.07
8.25
0.06
23.74
0.13
10.13
1.42
16.13
0.07
0.01
89.70
50.20
1.56
206.27
1,822.90

0.3
24.9
5.8
0.3
45.6
0.3
148.9
2.0
77.9
9.1
88.6
1.0
0.3
461.3
275.8
12.0
1,154.1
8,301.9

Emission reduction credits

A major source or major modification planned in a nonattainment area must obtain emissions
reductions as a condition for approval. These emissions reductions, generally obtained from
existing sources located in the vicinity of a proposed source, must offset the emissions increase
from the new source or modification. The obvious purpose of acquiring offsetting emissions
decreases is to allow an area to move towards attainment of the national ambient air quality
standards while still allowing some industrial growth.
Table 2.4–1 provides a list of emission reduction credits for carbon monoxide. Two facilities
shut down their equipment prior to 2002 and requested that their emissions continue to be listed
in the emission inventory for possible future use as emission reduction credits. A third facility
shut down operations in 2002 and received a credit generation certificate for their emissions from
the Arizona Emissions Bank. In order for these emission reductions to be available in the future
for offsetting, they must be: 1) explicitly included and quantified as growth in projection year
inventories required in rate of progress plans or attainment demonstrations that were based on
1990 actual inventories, and 2) meet the requirements outlined in MCESD Rule 240 (Permit
Requirements for New Major Sources and Major Modification to Existing Major Sources).
Table 2.4–1. CO emission reduction credits.
Facility
Anderson Clayton Oilseed Plant
Motorola (Mesa)
The Scottsdale Princess Cogeneration Partnership
Total
2002 Carbon Monoxide Periodic Emission Inventory

CO emission reduction credits (tons)
2.28
17
12.95
32.23
18

Maricopa County, AZ

2.5

CO point source emissions by process type

Table 2.5–1 lists annual and CO season-day emissions from the 113 point sources that reported
CO emissions.
Table 2.5–1. Annual and CO season-day point source emissions, by process type.
CATEGORY
Annual CO
emissions
ID # Business name
(tons/yr)
ELECTRICITY GENERATION:
Fuel Combustion: Fuel Oil:
3313 APS West Phoenix Power Plant
0.00
43063 Duke Energy Arlington Valley LLC †
0.11
3317 Kyrene Generating Station
0.00
98 Palo Verde Nuclear Generating Station
0.00
3316 SRP Agua Fria
0.01
0.13
Total Fuel Combustion: Fuel Oil
Fuel Combustion: Natural Gas
3313 APS West Phoenix Power Plant
116.58
43063 Duke Energy Arlington Valley LLC †
23.63
3317 Kyrene Generating Station
39.17
52382 Ocotillo Power Plant
69.05
42956 Pinnacle West Energy Corp. †
89.70
3315 Santan Generating Plant
339.66
3316 SRP Agua Fria
330.13
10469 SRP Desert Basin Generating Station †
50.20
1,058.12
Total Fuel Combustion: Natural Gas
TOTAL ELECTRICITY GENERATION:
1,058.25
COMMERCIAL/INSTITUTIONAL FUEL COMBUSTION:
Fuel Oil:
1074 23rd Ave. Wastewater Treatment Plant
1075 91st Ave. Wastewater Treatment Plant
4364 Arizona State University
4145 Cave Creek School District
51073 Charles Schwab & Co. Inc.
781 Good Samaritan Regional Medical Ctr.
3300 Luke Air Force Base
42636 Scottsdale Health Care Hospital
Total Commercial/Institutional Fuel Oil:
Natural Gas:
1074 23rd Ave. Wastewater Treatment Plant
4364 Arizona State University
4145 Cave Creek School District
781 Good Samaritan Regional Medical Ctr.
3300 Luke Air Force Base
42636 Scottsdale Health Care Hospital
232 The Phoenician Resort
Total Commercial/Institutional Natural Gas:
Other Fuels:
3300 Luke Air Force Base
TOTAL COMMERCIAL/
INSTITUTIONAL FUEL COMBUSTION:
† Source is outside the CO nonattainment area.

2002 Carbon Monoxide Periodic Emission Inventory

19

Season-day CO
emissions
(lbs/day)

0.0
3.5
0.0
0.0
0.1
3.5
429.6
145.4
18.7
343.9
461.3
1,042.9
762.8
275.8
3,480.5
3,484.0

0.03
0.45
0.02
0.05
0.92
4.96
0.71
0.44
7.58

0.0
13.1
0.0
0.5
5.0
13.5
5.5
3.9
41.6

0.76
15.12
3.16
3.28
4.20
0.94
9.98
37.44

7.3
138.7
24.3
18.0
36.9
6.6
52.8
284.7

0.61

3.6

45.63

329.9

Maricopa County, AZ

Table 2.5–1. Annual and CO season-day point source emissions, by process type (continued).
Annual CO
Season-day CO
CATEGORY
emissions
emissions
ID # Business name
(tons/yr)
(lbs/day)
INDUSTRIAL FUEL COMBUSTION:
Industrial Fuel Oil:
1874 Alleco Stone LLC †
199 Ameron Intl. Water Transmission Group
3938 Arizona Galvanizing Inc.
1218 Butterfield Station †
1267 Cemex Mesa Plants #61 & #71
26 Empire Machinery Co.
1418 Goodrich Aircraft Interior Products
3966 Intel Corp.-Ocotillo Campus (Fab 12 & 22)
31261 Madison Granite Supplies
1414 Mesa Materials Inc. (Mesa)
1415 Mesa Materials Inc. (Phoenix)
29474 Metal Management Arizona Inc.
1203 Microchip Technology Inc. (Chandler)
1875 Microchip Technology Inc. (Tempe)
882 Morton Salt Glendale Facility
881 Motorola Inc.
34197 National Gypsum Co.
1879 Northwest Regional Landfill
98 Palo Verde Nuclear Generating Station
537 Red Mountain Mining Inc.
266 Schuff Steel Co.
281 Sun State Rock & Materials
260 United Metro Plant #11
213 United Metro Plant #12
2 Vulcan Materials Co. (El Mirage)
398 Wickenburg Facility †
Total Industrial Fuel Oil:
Industrial Fuel Combustion: Natural Gas
245 A F Lorts Company Inc.
1952 Adesa Phoenix LLC
35541 Allied Tube & Conduit Corp.
199 Ameron Intl. Water Transmission Group
292 Anabolic Laboratories
3938 Arizona Galvanizing Inc.
43124 Bonded Logic Inc.
217 Building Products Co.
1310 Century Graphics LLC
1426 Cesar Color Inc.
1198 Courier Graphics Corp.
4368 Craftsmen in Wood Mfg.
130 Dolphin Inc.
508 Eagle Industries LLC
3305 Earthgrains Baking Companies Inc.
26 Empire Machinery Co.
27728 FlipChip International LLC
4050 General Mills
† Source is outside the CO nonattainment area.

2002 Carbon Monoxide Periodic Emission Inventory

20

3.89
0.18
0.66
0.26
2.14
2.25
0.02
1.16
14.59
16.28
11.22
0.16
0.01
0.02
2.37
0.44
0.06
1.42
14.27
1.43
0.74
0.73
0.16
0.19
1.98
1.56
78.22

24.9
7.1
5.1
1.7
10.4
12.1
0.4
44.6
112.3
75.1
51.8
1.0
0.3
0.9
18.3
17.1
0.8
9.1
78.4
11.0
4.7
4.7
2.1
1.2
10.2
12.0
517.2

0.01
0.01
0.33
0.35
0.12
2.32
0.16
16.73
0.04
0.41
0.20
0.06
1.71
0.02
1.53
18.91
0.28
0.67

0.1
0.0
1.9
3.9
0.9
12.7
1.3
92.3
0.3
3.1
1.4
0.5
12.1
0.2
9.8
98.5
1.5
4.1

Maricopa County, AZ

Table 2.5–1. Annual and CO season-day point source emissions, by process type (continued).
Annual CO
Season-day CO
CATEGORY
emissions
emissions
ID # Business name
(tons/yr)
(lbs/day)
INDUSTRIAL FUEL COMBUSTION: Natural Gas (cont'd.)
1418 Goodrich Aircraft Interior Products
31565 Henry Products Inc.
529 Highland Products Inc.
3536 Holsum Bakery Inc.
3802 Holsum Bakery Tempe
1059 Honeywell Engines Systems & Service
355 Honeywell International Inc.
777 Insulfoam
3966 Intel Corp. Ocotillo Campus (Fab 12 & 22)
983 Isola Laminate Systems Corp.
744 M. E. Global Inc.
205 Mail-Well Envelope
353 Marlam Industries Inc.
61268 Master Block Inc.
62 Mastercraft Cabinets Inc.
1203 Microchip Technology Inc. (Chandler)
1875 Microchip Technology Inc. (Tempe)
226 Monier Lifetile LLC
882 Morton Salt Glendale Facility
881 Motorola Inc.
223 MTD Southwest Inc.
693 Munters Corp.
34197 National Gypsum Co.
3953 Oakcraft Inc.
428 Paloma Gin Properties LLC
733 Pan-Glo West
1341 Penn Racquet Sports Inc.
289 Phoenix Agro Invest Inc.
1014 Phoenix Brick Yard
562 Phoenix Newspapers Inc.
148 Presto Casting Co.
60889 Purcell's Western States Tire
1030 Quebecor World Phoenix Division
303 Rexam Beverage Can Company
759 Rogers Corp. Advanced Circuit Materials
1437 Sanmina Phoenix Division
70634 Shell Oil Phoenix Terminal
31627 South Mountain Gin
4131 ST Microelectronics
1444 Staco Architectural Roof Tile
101 Sunland Beef Co.
249 The Boeing Company
1102 The Procter & Gamble Mfg. Co.
56 TPAC Division of Kiewit Western Co.
819 TRW Vehicle Safety Systems Inc.
234 United Dairymen of Arizona
260 United Metro Plant #11
213 United Metro Plant #12
403 VAW of America Inc.
† Source is outside the CO nonattainment area.

2002 Carbon Monoxide Periodic Emission Inventory

21

0.38
0.49
1.15
2.77
0.89
0.80
3.76
0.94
13.53
9.14
3.99
0.71
0.02
0.22
0.13
1.93
3.52
0.79
0.57
1.40
0.08
0.15
16.09
0.07
0.07
0.63
3.88
0.01
34.27
0.27
0.95
0.15
39.99
4.29
35.74
1.53
0.28
0.12
4.46
0.05
10.21
1.05
0.70
0.80
2.77
27.51
16.36
30.25
8.03

7.0
3.0
9.2
21.3
7.1
10.5
20.6
6.0
74.3
58.6
26.0
3.6
0.2
1.4
1.6
10.6
19.3
5.0
4.4
7.3
1.6
1.1
103.1
0.5
1.0
4.8
30.6
0.3
188.3
3.9
7.3
1.2
328.1
23.6
194.3
9.8
1.6
1.6
24.5
0.5
60.1
8.1
5.4
6.2
17.0
157.1
62.9
170.7
51.5

Maricopa County, AZ

Table 2.5–1. Annual and CO season-day point source emissions, by process type (continued).
Annual CO
Season-day CO
CATEGORY
emissions
emissions
ID # Business name
(tons/yr)
(lbs/day)
INDUSTRIAL FUEL COMBUSTION: Natural Gas (cont'd.)
2 Vulcan Materials Co. (El Mirage)
174 W. R. Meadows of AZ Inc.
20706 Wincup Holdings Inc.
72 Woodstuff Manufacturing Inc.
Total: Industrial Fuel Combustion: Natural Gas
Industrial Fuel Combustion: Other
31606 Acme Gin Co. Inc. †
31643 Allied Waste Industries Inc. †
31637 Anderson Clayton Corp. Valencia Gin †
3976 Cholla Custom Cabinets Inc.
1389 DaimlerChrysler AZ Proving Grounds †
1488 Farmers Gin Inc. †
1418 Goodrich Aircraft Interior Products
882 Morton Salt Glendale Facility
98 Palo Verde Nuclear Generating Station
Total: Industrial Fuel Combustion: Other
TOTAL: ALL INDUSTRIAL FUEL COMBUSTION:
INDUSTRIAL PROCESSES:
Engine Testing:
1059 Honeywell Engines Systems & Service
355 Honeywell International Inc.
3300 Luke Air Force Base
223 MTD Southwest Inc.
249 The Boeing Company
Total Engine Testing:
Other:
3442 Caljet
4175 SFPP LP
249 The Boeing Company
Total Other Industrial Processes:
TOTAL: ALL INDUSTRIAL PROCESSES
MANUFACTURING PROCESSES:
Electrical Equipment:
1875 Microchip Technology Inc.
Fabricated Metal Products:
10211 Hexcel Corp.
Secondary Metal Products:
354 Imsamet of Arizona
744 M. E. Global Inc.
403 VAW of America Inc.
Total: Manufacturing: Secondary Metal Products:
Other:
819 TRW Vehicle Safety Systems Inc.
TOTAL: ALL MANUFACTURING:
† Source is outside the CO nonattainment area.

2002 Carbon Monoxide Periodic Emission Inventory

22

0.05
0.16
11.19
0.07
343.21

0.2
2.0
56.6
0.5
2,068.0

0.02
0.90
0.07
0.01
0.06
0.13
1.10
0.87
1.85
5.01
426.44

0.3
5.8
0.3
0.1
0.3
2.0
8.0
6.7
10.2
33.7
2,618.9

1.19
16.37
5.12
46.04
0.29
69.01

7.6
90.0
39.4
354.1
2.3
493.3

4.30
8.62
0.15
13.06
82.07

23.6
47.3
1.2
72.1
565.5

0.06

0.3

10.13

77.9

80.66
52.24
2.62
135.51

460.9
401.1
16.8
878.7

0.41
146.12

2.9
959.9

Maricopa County, AZ

Table 2.5–1. Annual and CO season-day point source emissions, by process type (continued).
Annual CO
Season-day CO
CATEGORY
emissions
emissions
ID # Business name
(tons/yr)
(lbs/day)
WASTE DISPOSAL:
Landfills:
1218 Butterfield Station †
4173 Glendale Municipal Sanitary Landfill
27933 Skunk Creek Landfill
Total: Landfills
Publicly Owned Treatment Works (POTWs):
1074 23rd Ave. Wastewater Treatment Plant
1075 91st Ave. Wastewater Treatment Plant
Total: POTWs
Site Remediation:
3300 Luke Air Force Base
4175 SFPP LP
Total Site Remediation:
TOTAL: ALL WASTE DISPOSAL:
TOTAL: ALL POINT SOURCES:
† = Point source is outside the CO nonattainment area.

2.6

7.98
1.67
0.59
10.24

43.9
12.9
3.2
59.9

50.12
3.58
53.70

251.4
29.9
281.3

0.11
0.34
0.45
64.40

0.6
1.9
2.5
343.7

1,822.90

8,301.9

Summary of point source emissions

Table 2.6–1 provides an overview of source category contributions to total point source
emissions.
Table 2.6–1. Summary of annual and season-day point source emissions, by source category.
Maricopa County
CO nonattainment area
Annual
Season-day
Annual
Season-day
emissions
emissions
emissions
emissions
Source category
(tons/yr)
(lbs/day)
(tons/yr)
(lbs/day)
Electricity generation
1,058.25
3,484.0
894.61
2,598.0
Commercial/institutional fuel combustion
45.63
329.9
45.63
329.9
Industrial fuel combustion
426.44
2,618.9
401.93
2,472.6
Industrial processes
82.07
565.5
82.07
565.5
Manufacturing processes
146.12
959.9
135.99
882.0
Waste disposal
64.40
343.7
56.41
299.9
All point sources:
1,822.90
8,301.9
1,616.64
7,147.9

2.7

Quality assurance / quality control procedures

2.7.1

Emission survey preparation and data collection

The MCESD's Emissions Inventory (EI) Unit annually collects point source criteria pollutant
emission data from sources in the county. MCESD annually reviews EPA guidance, documents
from the Emission Inventory Improvement Program (EIIP), and other source materials to ensure
that the most current emission factors and emission calculation methods are used for each year's
survey. Each January, the EI Unit prepares a pre-populated hard copy of the preceding year’s
submissions and mails reporting forms to permitted sources, along with detailed instructions for
completing the forms. (A copy of these instructions is included as Appendix 2.1). The EI Unit
2002 Carbon Monoxide Periodic Emission Inventory

23

Maricopa County, AZ

asks sources to verify and update the data. The EI Unit also holds weekly workshops from
January through April to assist businesses in completing EI forms.
The general data flow for data collection and inventory preparation is shown in Figure 2.7–1.
Figure 2.7–1. Data flow for annual point source emission inventory reporting.

EI Reporting
Forms
• Hard Copy Forms/
Instructions
• Instruction on Web

EI Reporting
Forms

Log In EI
reports/ Issue
Receipts

Data Entry

EMS

Issue NOVs for
late submitters

•
•
•

Code/field check
Range checks
Referential value checks

Create
Inventory files

Automated QA checks

Technical QA/
QC

Using completed survey data

Finalized Inventory
Data
Reconciliation

2.7.2

Submission processing

Submitted EI reports are logged in as they are received, and receipts are issued for emissions fees
paid. The data are input “as received” into the department's data base. During data entry,
numerous automated quality control (QC) checks are performed, including:
•
•
•
•
•

pull-down menus to minimize data entry errors (e.g., city, pollutant, emission factor unit,
etc.)
mandatory data field requirement checks (e.g., a warning screen appears if a user tries to
save an emission record with a missing emission factor).
range checks (e.g., were valid SCC, Tier, SIC, and NAICS codes entered?)
referential value checks (e.g., emission factor units, annual throughput units)
automatic formatting of date, time, telephone number fields, etc.

2002 Carbon Monoxide Periodic Emission Inventory

24

Maricopa County, AZ

Automated quality assurance (QA) checks on the report that has been entered include the
following:
•
•
•
•

Comparing reported emission factors to SCC reference lists
Comparing reported emission factors to material name reference list
Checking the report for calculation errors. This includes annual throughput, emission
factors, unit conversion factors (e.g., BTU to therms), capture efficiency, primary /
secondary control device efficiency, and any offsite recycling credits claimed.
Checking the report for completeness of required data.

When data entry is complete, an electronic version of the original data is preserved separately to
document changes made during the technical review and QA/QC process.
When errors are flagged, the businesses are contacted and correct information is obtained and
input to the EMS. Outstanding reporting issues are documented. Confidential business
information (CBI) is identified by a checkbox on the form, and these data elements are flagged
during data entry and are not transmitted to the EPA. To prepare the inventory for submittal to
the National Emissions Inventory (NEI), the EI Unit runs Microsoft Access queries on the data in
the EMS to pull fields for the NEI Input format (NIF) tables.

2.7.3

Analysis of annual point source emissions data for this inventory

Two environmental planners checked inventory accuracy and reasonableness, and assured that
all point sources had been identified and that the methodology applied to calculate emissions was
appropriate and that the calculations were correct. Other reasonableness checks were conducted
by recalculating emissions using methods other than those used to make the initial emissions
calculations and then comparing results. QA was conducted by checking all emissions reports
submitted to MCESD for the year 2002 for missing and questionable data and by checking the
accuracy and reasonableness of all emissions calculations made for such reports. Notes
concerning follow-up calls and corrections to calculations were documented on each 2002 annual
emissions report.
The QA point source coordinator reviewed checked calculations, identified errors, and
performed completeness, reasonableness and accuracy checks.
2.8

References

US EPA, 2003. 2002 National Emission Inventory (NEI) Preparation Plan (draft). USEPA
Office of Air Quality Planning and Standards, Dec. 19, 2003. Available at:
http://www.epa.gov/ttn/chief/net/2002inventory.html

2002 Carbon Monoxide Periodic Emission Inventory

25

Maricopa County, AZ

2002 Carbon Monoxide Periodic Emission Inventory

26

Maricopa County, AZ

3.

Area Sources

3.1

Scope and methodology

This chapter considers all stationary sources which are too small or too numerous to be treated as
point sources. EPA guidance documents, including “Introduction to Area Source Inventory
Development” (US EPA, 2001) as well as permit and emissions data in the MCESD’s Environmental Management System (EMS) database, and previous SIP inventories, were evaluated to
develop the list of area source categories for inclusion. Some source categories were deemed
“insignificant” because there are no large production facilities and/or very few small sources, and
therefore emissions were not quantified. MCESD prepared the area source emission estimates
for all area sources and provided quality assurance checks on all data. Table 3.1–1 contains a list
of all area source categories, with Source Classification Codes (SCCs), addressed in this chapter.
Table 3.1–1. List of area source categories.
AMS code
Area source description
Fuel combustion:
2102006000 Industrial natural gas
2102004000 Industrial fuel oil
2103006000 Commercial/institutional natural gas
2103004000 Commercial/institutional fuel oil
2104006000 Residential natural gas
2104008000 Residential wood
2104004000 Residential fuel oil

Section
3.2.1
3.2.2
3.2.3
3.2.4
3.2.5
3.2.6
3.2.7

2301000000
2302002000
n/a
2399000000

Industrial processes:
Chemical manufacturing
Commercial cooking
State-permitted portable sources
Industrial processes not elsewhere classified

3.3.1
3.3.2
3.3.3
3.3.4

2601000000
2610000000
2620000000

Waste treatment and disposal:
On-site incineration
Open burning
Landfills

3.4.1
3.4.2
3.4.3

2810001000
2810030000
2810050000
2810040000
2601020000
2830000000

Miscellaneous area sources:
Wildfires and brush fires
Structure fires
Vehicle fires
Engine testing
Health services (crematories)
Accidental releases

3.5.1.1
3.5.1.2
3.5.1.3
3.5.1.4
3.5.2
3.5.3

For nearly all categories, emissions were calculated in one of the following ways:
• emissions estimates for some categories were developed by conducting surveys on local
usage (e.g., natural gas consumption, pesticide usage) or derived from state-wide data
(e.g., fuel oil use).
• for some widespread or diverse categories (e.g., consumer solvent use), emissions were
calculated using published per-capita or per-employee emission factors.
• for source categories with some information available from annual emissions reports
(e.g., bakeries), these data were combined with employment data to “scale up” reported
emissions to reflect the entire source category.
2002 Carbon Monoxide Periodic Emission Inventory

27

Maricopa County, AZ

•

for those source categories with detailed emissions data available from most or all
significant sources in the category, emissions were calculated based on detailed process
and operational data provided by these sources.

The specific emissions estimation methodologies used for each source category (including any
application of rule effectiveness) are described in greater detail in the respective sections.

3.2

Fuel combustion

Area source emissions for the following seven categories of fuel consumption were calculated:
Industrial natural gas, industrial fuel oil, commercial/institutional natural gas, commercial
institutional fuel oil, residential natural gas, residential wood, and residential fuel oil. Data for
emissions calculations from natural gas combustion came from a survey of the four natural gas
suppliers in Maricopa County. The following table summarizes the natural gas sales data
received from Maricopa County natural gas suppliers.
Table 3.2–1. Natural gas sales data from Maricopa County natural gas suppliers.
Sales by end user category (in MMCF/yr)
Natural gas
Electric
Commercial/
supplier
Utilities
Institutional
Industrial
Residential
Transport*
Southwest Gas
n/a
3,092.760
13,774.986
14,842.508
3,802.155
City of Mesa
80.169
386.692
1,486.877
1,112.936
59.924
El Paso
58,334.169
161.429
n/a
n/a
n/a
Black Mountain
n/a
n/a
142.561
464.084
n/a
* For emissions calculations, sales from these two categories were grouped with industrial sales.

Other*
1,977.644
n/a
n/a
n/a

Area source emissions for wood and fuel oil combustion were calculated from Arizona statelevel sales and consumption data as described in the following subsections. Area source emissions from coal and liquid petroleum gas were not calculated as emissions from these categories
were determined to be insignificant.

3.2.1

Industrial natural gas

All natural gas suppliers in Maricopa County were surveyed to gather information on the volume
of natural gas distributed, by user category, within the county in 2002. Area source industrial
natural gas usage for the county is based on the reported total volume of natural gas sold to
industrial sources, minus natural gas used by industrial point sources:
Area source industrial
natural gas usage

= Reported industrial
natural gas sales
= 9,480.60 MMCF
= 1,551.23 MMCF

– Industrial point source
natural gas usage
– 7,929.38 MMCF

Natural gas is used for both external combustion (boilers, heaters) and internal combustion
(generators), each of which have different emission factors. Thus the area source natural gas
usage derived above must be apportioned between these two categories. This apportionment was
based on the percentages of external and internal natural gas combustion reported by all
industrial area sources in 2002.
2002 Carbon Monoxide Periodic Emission Inventory

28

Maricopa County, AZ

Annual emissions for the county are calculated by multiplying natural gas usage by the
respective AP-42 emission factors for external and internal combustion, as in this example for
CO emissions from external natural gas combustion:
Annual CO emissions
= External industrial natural × CO emission factor for
÷ 2,000 lb/ton
from external natural gas
gas usage (MMCF)
external natural gas comcombustion
bustion (lb/MMCF)
= 1,527.09
× 84
÷ 2,000
= 64.14 tons CO/yr
Table 3.2–2. Emission factors and annual emissions from area-source industrial natural gas combustion, by
combustion type.
% of
Annual natural gas CO emission factor Annual emissions
Combustion type
total
usage (MMCF)
(lbs/MMCF)
(tons/yr)
External
98.44
1,527.09
84
64.14
Internal
1.56
24.14
399
4.82
Totals:
100.00
1,551.23
68.95

Season-day emissions for the county are calculated by first multiplying annual emissions by the
percentage of industrial natural gas sold used during the CO season. (Figures reported by natural
gas suppliers for the December–February time period are assumed to be representative for the
November–January CO season.) CO season emission totals are then divided by the number of
days that activity occurs during the CO season:
Season-day CO
= Annual CO
× % natural gas sold
emissions from
emissions (tons/yr)
during CO season
industrial natural gas
= 68.95
× 28.59 %
= 505.5 lbs/day

÷ (days/week × wks/season) × 2,000 lbs/ton

÷ (6 × 13)

× 2,000

Annual and season-day emissions within the CO nonattainment area are calculated by applying
the ratio of industrial employment in the nonattainment area to county-level emission
calculations. (See Section 1.5.1 for a discussion of the employment data used).
Emissions from area source
industrial natural gas combustion
in the CO NAA

= Annual county CO
emissions (tons/yr)

× Industrial employment ratio

= 68.95
= 67.64 tons CO/yr

× 0.9809

Table 3.2–3. Annual and season-day emissions from area-source industrial natural gas combustion.
Annual emissions Season-day emissions
Geographic area
(tons/yr)
(lbs/day)
Maricopa County
68.95
505.5
CO NAA
67.64
495.9

2002 Carbon Monoxide Periodic Emission Inventory

29

Maricopa County, AZ

3.2.2

Industrial fuel oil

Area source emissions from industrial fuel oil combustion are calculated by a multi-step process
which allocates Arizona state-level industrial fuel oil sales data from the US Department of
Energy, Energy Information Administration (US DOE, 2002b) to Maricopa County.
To derive industrial fuel oil usage in Maricopa County, reported Arizona sales of high-sulfur
diesel for 2002 are first subtracted from Arizona state-level total industrial fuel oil sales, as it is
presumed that no high-sulfur diesel fuel is used in Maricopa County due to local air quality
regulations and market conditions.
State industrial fuel oil sales
other than high-sulfur diesel
(in thousand gallons, or Mgal)

= Reported state total
– Reported state high-sulfur diesel sales
industrial fuel oil sales
= 61,748 Mgal
– 34,076 Mgal
= 27,672 Mgal/yr

Arizona state industrial fuel oil sales (less high-sulfur diesel fuel) are then multiplied by the ratio
of industrial employment in Maricopa County to Arizona state (0.71), as determined from data
from the US Census (2003a) to estimate annual Maricopa County industrial fuel oil sales, as
follows:
Maricopa County
= Arizona industrial fuel oil
industrial fuel oil sales
sales less high-sulfur diesel
= 27,672 Mgal
= 19,647.12 Mgal/yr

× Maricopa County:state
industrial employment ratio
× 0.71

To avoid double-counting, industrial fuel oil use attributable to stationary point sources
(addressed in Chapter 2) and nonroad mobile sources (addressed in Chapter 4) are subtracted
from County industrial fuel oil sales to estimate county fuel oil usage by area sources, as follows:
Maricopa County industrial = Maricopa County
– Fuel oil used by industrial – Fuel oil used by industrial
area source fuel oil sales
industrial fuel oil sales
nonroad mobile equipment
stationary point sources
= 19,647.12 Mgal
– 7,365.927 Mgal
– 2,021.10 Mgal
= 10,260.097 Mgal/yr

Industrial fuel oil is used for both external combustion (boilers, heaters) and internal combustion
(generators), each of which have different emission factors. Thus the area source industrial fuel
oil sales derived above must be apportioned between these two categories. This apportionment
was based on the percentages of external and internal fuel oil combustion reported by all
industrial area sources surveyed by MCESD in 2002 (shown in Table 3.2–4 below).
County-level annual emissions from this area source category were calculated by multiplying
industrial fuel oil sales by the respective AP-42 emission factors for external and internal
combustion, as in this example for CO emissions from external industrial fuel oil combustion:
Annual CO emissions
= External industrial fuel
from external industrial
oil sales (Mgal)
fuel oil combustion
= 8,003.949
= 20.01 tons CO/yr

2002 Carbon Monoxide Periodic Emission Inventory

× CO emission factor for external ÷ 2,000 lb/ton
fuel oil combustion (lb/Mgal)
× 5

30

÷ 2,000

Maricopa County, AZ

Table 3.2–4. Emission factors and annual emissions from area-source industrial fuel oil combustion, by
combustion type.
% of
Annual fuel oil
CO emission
Annual emissions
Combustion type
total
sales (Mgals)
factor (lbs/Mgals)
(tons/yr)
External
78.01
8,003.949
5
20.01
Internal
21.99
2,256.147
130
146.65
Totals:
100.00
10,260.097
166.66

Season-day emissions for the county are calculated by first multiplying annual emissions by 25%
to estimate CO season emission totals. CO season emission totals are then divided by the
number of days that activity occurs during the CO season, as recommended by EIIP guidance
(US EPA, 2001a):
CO season-day
emissions from
industrial fuel oil

= Annual CO
× % fuel oil sold
÷ (days/week × wks/season) × 2,000 lbs/ton
emissions (tons/yr)
during CO season
= 166.66
= 1,068.3 lbs/day

× 25 %

÷ (6 × 13)

× 2,000

Annual and season-day emissions in the CO nonattainment area are calculated by applying the
ratio of industrial employment in the nonattainment area to county-level emission calculations.
(See Section 1.5.1 for a discussion of the employment data used).
CO NAA emissions from area
source industrial fuel oil combustion

= Annual county CO
emissions (tons/yr)
= 166.66 tons/yr
= 163.48 tons CO/yr

× NAA:County industrial employment ratio
× 0.9809

Table 3.2–5. Annual and season-day emissions from area-source industrial fuel oil combustion.
Annual emissions
Season-day
(tons/yr)
emissions (lbs/day)
Geographic area
Maricopa County
166.66
1,068.3
CO NAA
163.48
1,047.9

3.2.3

Commercial/institutional natural gas

All natural gas suppliers in Maricopa County were surveyed to gather information on the volume
of natural gas distributed, by user category, within the county in 2002. Area source commercial
and institutional (C&I) natural gas usage for the county is based on the reported total volume of
natural gas sold to C&I sources, minus natural gas used by C&I point sources:
County area source C&I
natural gas usage

= Reported C&I
natural gas sales
= 15,404.42 MMCF
= 14,679.07 MMCF

– C&I point source
natural gas usage
– 725.35 MMCF

Natural gas is used for both external combustions (boilers, heaters) and internal combustion
(generators), each of which have different emission factors. Thus the area source natural gas
usage derived above must be apportioned between these two categories. This apportionment was
based on the percentages of external and internal natural gas combustion reported by all C&I
area sources in 2002.
2002 Carbon Monoxide Periodic Emission Inventory

31

Maricopa County, AZ

Annual emissions for the county and the CO nonattainment area are calculated by multiplying
natural gas usage by the respective AP-42 emission factors for external and internal combustion,
as in this example for CO emissions from external natural gas combustion:
Annual CO emissions
= External C&I natural
from external natural gas
gas usage (MMCF)
combustion
= 14,434.79
= 606.26 tons CO/yr

× CO emission factor for
÷ 2,000 lb/ton
external natural gas combustion (lb/MMCF)
× 84
÷ 2,000

Table 3.2–6. Emission factors and annual emissions from area-source commercial/institutional natural gas
combustion, by combustion type.
% of
Annual natural gas CO emission factor Annual emissions
Combustion type
total
usage (MMCF)
(lbs/MMCF)
(tons/yr)
External
98.34
14,434.79
84
606.26
Internal
1.66
244.29
399
48.74
Totals:
100.00
14,679.07
655.00

Season-day emissions for the county are calculated by first multiplying annual emissions by the
percentage of C&I natural gas sold used during the CO season. (Figures reported by natural gas
suppliers for the December–February time period are assumed to be representative for the
November–January CO season.) CO season emission totals are then divided by the number of
days that activity occurs during the CO season:
Season-day CO
emissions from
C&I natural gas

= Annual CO
× % natural gas sold
emissions (tons/yr)
during CO season

÷ (days/week × wks/season) × 2,000 lbs/ton

= 655.00
= 5,594.0 lbs/day

÷ (6 × 13)

× 33.31 %

× 2000

Annual and season-day emissions in the CO nonattainment area are calculated by applying the
combined ratio of retail, office, public and other employment in the nonattainment area to
county-level emission calculations. (See Section 1.5.1 for a discussion of the employment data
used).
Emissions from area source
C&I natural gas combustion
in the CO NAA

= Annual county CO
emissions (tons/yr)

× NAA:County C&I employment ratio

= 655.00
= 643.80 tons CO/yr

× 0.9829

Table 3.2–7. Annual and season-day emissions from area-source commercial/institutional natural gas
combustion.
Annual emissions Season-day emissions
(tons/yr)
(lbs/day)
Geographic area
Maricopa County
655.00
5,594.0
CO NAA
643.80
5,498.4

2002 Carbon Monoxide Periodic Emission Inventory

32

Maricopa County, AZ

3.2.4

Commercial/institutional fuel oil

Area source emissions from commercial and institutional (C&I) fuel oil combustion are calculated by a multi-step process of allocating Arizona state-level C&I fuel oil sales as reported by
the US Department of Energy, Energy Information Administration (US DOE, 2002a) to
Maricopa County.
To derive commercial/institutional fuel oil usage in Maricopa County, reported Arizona statelevel sales of high-sulfur diesel for 2002 are first subtracted from Arizona state-level total
commercial/institutional fuel oil sales, as it is presumed that no high-sulfur diesel fuel is used in
Maricopa County due to local clean air act requirements and market conditions.
State C&I fuel oil sales
other than high-sulfur diesel
(in thousand gallons, or Mgal)

= Reported state total
C&I fuel oil sales
= 30,077 Mgal
= 30,006 Mgal/yr

– Reported state high-sulfur diesel sales
– 71 Mgal

Arizona state commercial/institutional fuel oil sales less high-sulfur diesel are then multiplied by
the ratio of C&I employment in Maricopa County to Arizona state (0.71), as determined by data
from the US Census (2003a), to estimate Maricopa County-level C&I fuel oil sales, as follows:
Maricopa County
C&I fuel oil sales

= Arizona C&I fuel oil
sales less high-sulfur diesel
= 30,006 Mgal
= 21,304.26 Mgal/yr

× Maricopa County:state
C&I employment ratio
× 0.71

To avoid double-counting, commercial/institutional fuel oil use attributable to stationary point
sources (addressed in Chapter 2) and nonroad mobile sources (addressed in Chapter 4) are
subtracted from County C&I fuel oil sales to estimate county fuel oil usage used by C&I area
sources, as follows:
Maricopa County C&I
area source fuel oil sales

= Maricopa County
– Fuel oil used by C&I
– Fuel oil used by C&I
C&I fuel oil sales
nonroad mobile equipment
stationary point sources
= 21,304.26 Mgal
– 4,435.974 Mgal
– 190.672 Mgal
= 16,677.614 Mgal/yr

Fuel oil is used for both external combustion (boilers, heaters) and internal combustion
(generators), each of which have different emission factors. Thus the area source C&I fuel oil
sales derived above must be apportioned between these two categories. This apportionment was
based on the percentages of external and internal fuel oil combustion reported by all
commercial/institutional area sources surveyed by MCESD in 2002 (shown in Table 3.2–8
below).
Annual emissions for the county are calculated by multiplying C&I fuel oil sales by the
respective AP-42 emission factors for external and internal combustion, as in this example for
CO emissions from external C&I fuel oil combustion:

2002 Carbon Monoxide Periodic Emission Inventory

33

Maricopa County, AZ

Annual CO emissions
from external C&I
fuel oil combustion

= External C&I fuel
oil sales (Mgal)

× CO emission factor for external
fuel oil combustion (lb/Mgal)

÷ 2,000 lb/ton

= 11,165.542
= 27.91 tons CO/yr

× 5

÷ 2,000

Table 3.2–8. Emission factors and annual emissions from area-source commercial/institutional fuel oil
combustion, by combustion type.
% of
Annual fuel oil
CO emission
Annual emissions
total
sales (Mgals)
factor (lbs/Mgals)
(tons/yr)
Combustion type
External
66.95
11,165.542
5
27.91
Internal
33.05
5,512.072
130
358.28
Totals:
100.00
16,677.614
386.20

Season-day emissions for the county are calculated by first multiplying annual emissions by 35%
to estimate CO season emission totals. CO season emission totals are then divided by the
number of days that activity occurs during the CO season as recommended by EIIP guidance
(US EPA, 2001a):
CO season-day
emissions from
C&I fuel oil use

= Annual CO
× % fuel oil sold
÷ (days/week × wks/season) × 2,000 lbs/ton
emissions (tons/yr)
during CO season
= 386.20
= 3,465.9 lbs/day

× 35 %

÷ (6 × 13)

× 2,000

Annual and season-day emissions within the CO nonattainment area are calculated by applying
the combined ratio of retail, office, public and other employment in the nonattainment area to
county-level emission calculations. (See Section 1.5.1 for a discussion of the employment data
used).
CO NAA emissions from area
source C&I fuel oil combustion

= Annual county CO
emissions (tons/yr)
= 386.20
= 379.59 tons CO/yr

× NAA:County C&I employment ratio
× 0.9829

Table 3.2–9. Annual and season-day emissions from area-source commercial/institutional fuel oil
combustion.
Annual emissions
Season-day
Geographic area
(tons/yr)
emissions (lbs/day)
Maricopa County
386.20
3,465.9
CO NAA
379.59
3,406.6

3.2.5

Residential natural gas

All natural gas suppliers in Maricopa County were surveyed to gather information on the volume
of natural gas sold, by user category, within the county. Annual emissions from residential
natural gas combustion emissions were calculated by multiplying residential natural gas sales by
emission factors for residential natural gas combustion listed in AP-42 Tables 1.4-1 and 1.4-2
(US EPA, 1998), as follows:

2002 Carbon Monoxide Periodic Emission Inventory

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Maricopa County, AZ

Annual emissions from = Residential natural
residential natural gas
gas annual sales
combustion
(MMCF)
= 16,419.53
= 328.39 tons CO/yr

× Residential natural gas
emission factor for CO
(lbs/MMCF)
× 40

÷ 2,000 lbs/ton

÷ 2,000 lbs/ton

CO season-day emissions are calculated by first multiplying reported natural gas usage during
the CO season (5,989.84 MMCF) by the emission factor for CO for residential natural gas
combustion to produce CO season emissions (natural gas usage reported for the months of
December-February are assumed to represent CO season usage). CO season emissions are then
divided by the number of days during the CO season that residential natural gas combustion
occurs (US EPA, 2001a).
Season-day emissions = Residential natural × Residential natural gas
from residential natural
gas seasonal sales
emission factor for CO
gas combustion
(MMCF)
(lbs/MMCF)
= 5,989.84
× 40
= 2,632.9 lbs CO/day

÷ (days/week × weeks/season)

÷ (7 × 13)

Annual and season-day residential natural gas emissions in the CO nonattainment area are
calculated by multiplying county-level emissions by the percentage of total occupied households
(98.18%) in the CO nonattainment area as follows:
Annual emissions from
residential natural gas
combustion in the NAA

= County annual emissions

× Percentage of occupied households in the NAA

= 328.39 tons/yr
= 322.41 tons CO/yr

× 98.18%

Table 3.2–10. Annual and season-day emissions from residential natural gas combustion.
Annual emissions
CO season-day
Geographic area
(tons/year)
emissions (lbs/day)
Maricopa County
328.39
2,632.9
CO NAA
322.41
2,585.0

3.2.6

Residential wood combustion

Area source emissions from residential wood combustion are calculated based on the amount of
wood burned in fireplaces and woodstoves in Maricopa County, as recommended by EIIP
guidance (US EPA, 2001b). Residential wood combustion in the county is estimated by multiplying data on statewide residential wood combustion usage from the US Department of Energy
(2003) by the ratio of county to state households that report use of wood for heating from the US
Census Bureau (2003c). The latest available data on residential wood use for household heating
from the US Census Bureau is for the calendar year 2000. Since all fireplaces in homes constructed since 1999 are required by Arizona statute to be clean-burning, it is assumed that these
new homes have negligible emissions. Thus, year 2000 data is assumed to be representative of
2002 emissions.

2002 Carbon Monoxide Periodic Emission Inventory

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Maricopa County, AZ

Maricopa County residential = Arizona residential × Ratio of county:state households
wood usage (cords/yr)
wood usage (cords/yr) using wood for heat
= 491,000
× 1,655 / 39,842
= 20,396 cords/yr

To calculate emissions, the amount of wood used is converted to tons by multiplying cords by
the number of cubic feet of wood in a cord and by the density of the wood used (US EPA,
2001b). Wood density is determined by weighted average of types of wood used for residential
combustion in Maricopa County, provided by the US Forest Service (USFS, 1993).
County residential
= County wood × avg. ft3 wood/cord × Wood density (lbs/ ft3) ÷ 2,000 lbs/ton
wood usage (tons/yr)
usage (cords)
= 20,396
× 79
× 31.57
÷ 2,000
= 25,433.73 tons

Annual emissions from residential wood combustion are calculated by multiplying the tons of
wood used by the CO emission factor for residential total woodstoves and fireplaces from EIIP
Volume III, Chap. 2, Table 2.4-1 (US EPA, 2001b):
Annual CO emissions from resid- = Residential
× CO emission factor (lbs/ton)
ential wood combustion (tons/yr)
wood usage (tons)
= 25,433.73
× 252.6
= 3,212.28 tons CO/yr

÷ 2,000 lbs/ton
÷ 2,000

Following EIIP guidance, season-day CO emissions are calculated by apportioning wood
burning activity based on heating degree days (i.e., the number of degrees per day that the daily
average temperature is below 65°F). Data provided by Arizona State University (2003) indicated
that there were a total of 776 heating degree days in Phoenix during 2002, with 586 heating
degrees days reported during the CO season. By applying the ratio of CO season heating degree
days to annual heating degree days, CO season-day emissions are calculated as follows:
Season-day CO emissions = Annual emissions × Heating degree days × 2,000 lbs/ton ÷ CO season-days/yr
from residential wood
(tons/yr)
(ratio)
combustion (lbs/day)
= 3,212.28
× (586 / 776)
× 2,000
÷ 91
= 53,313.6 lbs/day

Annual and season-day emissions within the CO nonattainment area (NAA) are calculated by
multiplying county totals by the ratio of total occupied housing units inside the nonattainment
area (1,337,099) to total residential housing units in the county (1,361,837). See Section 1.5.1
for a further discussion of the housing data used.
NAA annual emissions = County annual emissions
from residential wood
(tons/yr)
combustion (tons/yr)
= 3,212.28
= 3,153.82 tons/yr

2002 Carbon Monoxide Periodic Emission Inventory

× NAA:county residential housing ratio

× 0.9818

36

Maricopa County, AZ

Table 3.2–11. Annual and season-day emissions from residential wood combustion.
Annual emissions Season-day emissions
(tons/yr)
(lbs/day)
Geographic area
Maricopa County
3,212.28
53,313.6
CO NAA
3,153.82
52,343.3

3.2.7

Residential fuel oil

Emissions from residential fuel oil use were calculated using an approach similar to that used for
residential wood combustion described in Section 3.2.6. County-level residential fuel oil use
was derived from statewide totals using the ratio of county to state households that report fuel oil
use from the US Census Bureau (2003b):
Maricopa County residential = Arizona residential × Ratio of county:state households
fuel oil usage (Mgal/yr)
fuel oil use (Mgal/yr)
reporting fuel oil use
= 340
× 490 / 1,813
= 91.89 Mgal/yr

An AP-42 emission factor of 5 lbs CO/Mgal, and data on heating degree days and residential
housing units described in Section 3.2.6, were used to calculate annual and daily CO emissions
shown in Table 3.2–12.
Table 3.2–12. Annual and season-day emissions from residential fuel oil combustion.
Annual emissions Season-day emissions
Geographic area
(tons/yr)
(lbs/day)
Maricopa County
0.23
3.8
CO NAA
0.23
3.7

3.2.8

Summary of all area-source fuel combustion

Table 3.2–13. Summary of annual and season-day area source fuel combustion.
Maricopa County
CO nonattainment area
Annual
Season-day
Annual
Season-day
emissions
emissions
emissions
emissions
Source category
(tons/yr)
(lbs/day)
(tons/yr)
(lbs/day)
Industrial natural gas
68.95
505.5
67.64
495.9
Industrial fuel oil
166.66
1,068.3
163.48
1,047.9
Commercial/institutional natural gas
655.00
5,594.0
643.80
5,498.4
Commercial/institutional fuel oil
386.20
3,465.9
379.59
3,406.6
Residential natural gas
328.39
2,632.9
322.41
2,585.0
Residential wood
3,212.28
53,313.6
3,153.82
52,343.3
Residential fuel oil
0.23
3.8
0.23
3.7
Totals:
4,817.71
66,584.1
4,730.96
65,380.8

2002 Carbon Monoxide Periodic Emission Inventory

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Maricopa County, AZ

3.3

Industrial processes

3.3.1

Chemical manufacturing

Emissions from area-source chemical manufacturing were calculated by the “scaling up” method
as described in EPA emission inventory guidance (US EPA, 2001a). This method combines
detailed emissions data from a subset of sources, and county-level employment data from the US
Census Bureau (2003b) to develop a per-employee emission factor that is then used to estimate
emissions from all sources in an industry category.
The most recent data from the US Census’ County Business Patterns (CBP) for 2001
employment, were used. Where CBP employment estimates were presented as a range, the
midpoint values was chosen for these calculations. Table 3.3–1 shows the NAICS codes and
employment data used to calculate emissions from chemical manufacturing.
Table 3.3–1. NAICS codes and descriptions for chemical manufacturing.
NAICS
US Census
Code
Description
employment data
32551 Paint & coating manufacturing
100–249
32591 Printing ink manufacturing
20–99
422910 Farm supplies, wholesale
298
325991 Custom compounding of purchased resin
100–249
325998 All other misc. chemical product & prep. manufacturing
316
325188 All other basic inorganic chemical manufacturing
100–249
325412 Pharmaceutical manufacturing
500–999
Total:

Value
used
175
60
298
175
316
175
750
1,949

Some facilities in this category are considered point sources, and have been addressed in Chapter
2. To avoid double-counting, employment at point sources is subtracted from total employment
as follows:
Total area-source
employment in
chemical mfg.

= Total employment (from US
– Employment at point sources
Census’ County Business Patterns)
(from annual emission reports)
= 1,949

– 191

= 1,758 employees

This area-source employment estimate is used to “scale up” emissions reported from those
facilities surveyed in 2002 as follows:
Total area-source = Emissions from surveyed area sources × Total area-source employment
emissions
Employment at surveyed area sources
Area-source CO
emissions from
chemical mfg.

=

0.03 tons/yr
744 employees

× 1,758 employees

= 0.07 tons CO/yr

CO season-day emissions are calculated based on the operating schedule data reported by chemical manufacturing facilities. From annual emission surveys, the modal values were identified
for two items: days/week and seasonal activity as a percentage of annual activity. This data was
used to calculate typical season-day emissions as follows:
2002 Carbon Monoxide Periodic Emission Inventory

38

Maricopa County, AZ

Season-day CO
emissions from
chemical mfg.

= Annual emissions (tons/yr) × season %
Days/week × Weeks/season

× 2,000 lbs
ton

=

× 2,000

=

0.07 × 25%
5 × 13
0.5 lbs CO/day

Annual and season-day emissions for the CO nonattainment area were calculated by multiplying
the Maricopa County emission totals by the percentage industrial employment within the
nonattainment area. (See Section 1.5.1 for a discussion of the employment data used.)
CO emissions from
area-source chemical mfg.
in the CO NAA (tons/yr)

= Annual Maricopa County
emissions

× NAA:county ratio of
industrial employment

= 0.07 tons/yr

× 98.09%

= 0.07 tons CO/yr

Table 3.3–2 summarizes annual and season-day emissions from chemical manufacturing in both
Maricopa County and the CO nonattainment area.
Table 3.3–2. Annual and season-day emissions from area-source chemical manufacturing.
Annual CO emissions
Season-day CO emissions
Geographic area
(tons/yr)
(lbs/day)
Maricopa County
0.07
0.5
CO NAA
0.07
0.5

3.3.2

Commercial cooking

Emissions from commercial cooking were estimated for five source categories based on equipment type. These equipment types include: chain-driven (conveyorized) charbroilers (SCC
2302002100), under-fired charbroilers (2302002200), flat griddles (2302003100), clamshell
griddles (2302003200), and deep-fat fryers (2302003000). Emission inventory methods outlined
in EPA guidance (US EPA, 2004) for these source categories include emissions from all meat
types (hamburger, steak, fish, pork, and chicken) and five restaurant types (ethnic, fast food,
family, seafood, and steak & barbeque).
Data obtained from MCESD’s eating and drinking establishments permit database indicated that
9,038 restaurants operated in Maricopa County in 2002. The percent of restaurants in Maricopa
County for the five restaurant types was obtained from a commercial business database (Harris
InfoSource, 2003). The percent of restaurants for each restaurant type was multiplied by the total
number of restaurants operated in Maricopa County in 2002 to derive the number of restaurants
for each restaurant type as shown in Table 3.3–3.
Using the number of restaurants for each restaurant type, along with the default emission factors
and equations from US EPA (2004), emissions for each combination of equipment type, restaurant type, and meat type were calculated, and the results were summed to estimate annual
emissions for each type of cooking equipment, as shown in Table 3.3–4.

2002 Carbon Monoxide Periodic Emission Inventory

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Maricopa County, AZ

Table 3.3–3. Maricopa County restaurants, by type.
Restaurant category
Percentage
# of restaurants
Ethnic food
14.47
1,308
Fast food
15.35
329
Family
3.64
1,387
Seafood
0.61
55
Steak & barbecue
1.15
104
Unrelated restaurant types
(e.g., lunchrooms, bars)
64.79
5,856
All restaurants:
100.00
9,038

Table 3.3–4. Annual emissions from commercial cooking, by equipment type.
Annual CO emissions
Equipment type
(tons/yr)
Chain-driven charbroilers
60.75
Underfired charbroilers
196.43
Deep fat fryers
0.00
Flat griddles
16.32
Clamshell griddles
0.00
Total:
273.50

Commercial cooking is assume to occur uniformly throughout the year, therefore, it was
assumed that 25% of annual activity occurs during the CO season, and activity occurs 7
days/week.
Table 3.3–5. Season-day emissions from commercial cooking, by equipment type.
CO season-day emissions
(lbs/day)
Equipment type
Chain-driven charbroilers
333.8
Underfired charbroilers
1,079.3
Deep fat fryers
0.0
Flat griddles
89.7
Clamshell griddles
0.0
Total:
1,502.8

Annual and season-day emissions for the CO nonattainment area were calculated by multiplying
the Maricopa County emission totals by the percentage population within the nonattainment area
(98.09%). (See Section 1.5.1 for a discussion of the population data used.) Table 3.3–6
summarizes the annual and season-day emissions from commercial cooking for Maricopa
County and the CO NAA.
Table 3.3–6. Annual and season-day emissions from commercial cooking.
Maricopa County
CO nonattainment area
Annual
Season-day
Annual
Season-day
emissions
emissions
emissions
emissions
Equipment type
(tons/yr)
(lbs/day)
(tons/yr)
(lbs/day)
Chain-driven charbroilers
60.75
333.8
59.59
327.4
Underfired charbroilers
196.43
1,079.3
192.68
1,058.7
Deep fat fryers
0.00
0.0
0.00
0.0
Flat griddles
16.32
89.7
16.01
88.0
Clamshell griddles
0.00
0.0
0.00
0.0
Totals:
273.50
1,502.8
268.28
1,474.1

2002 Carbon Monoxide Periodic Emission Inventory

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Maricopa County, AZ

3.3.3

State-permitted portable sources

The Arizona Department of Environmental Quality (ADEQ) retains the authority to permit
certain categories of sources within Maricopa County, including portable sources. MCESD
requested information from ADEQ for all ADEQ-permitted sources that reported any activity in
Maricopa County during 2002. Annual total emissions for each pollutant were provided, along
with information on the facility type, and information on the location of the site during the year.
Permits were classified into four major types: asphalt batch, concrete batch, crushing/screening,
and other (including soil remediation, generators, etc.). From this information, emissions that
occurred within Maricopa County were estimated as in the following example.
Data provided:
Source information:
Permit type:
Operating schedule:
Total annual emissions:

Fisher Sand & Gravel - Arizona Crusher #1, ID 13464
Portable crushing/screening plant
Operated in Maricopa County 1/3/02 to 4/20/02, Gila County from 4/30/02 to 6/15/02
and 6/20/02 to 11/02/02, and in Greenlee County from 11/08/02 to 12/31/02
1.7592 tons CO/year

Using this information, calculations were made to determine:
Total operating days in 2002:
345 = 29 (Jan.) + 28 (Feb.) + … + 31 (Dec.)
Total operating days in Maricopa County: 108 = 29 (Jan.) + 28 (Feb.) + 31 (Mar.) + 20 (April)
Any operating days in Maricopa County
during CO season? (December–February): yes

All emissions were assumed to be equally distributed among all reported days of operation.
First, the total emissions attributable to activity in Maricopa County was calculated as follows:
Annual CO emissions
in Maricopa County

= Total annual emissions × operating days in Maricopa County
(tons/yr)
total operating days in 2002
= 1.7592

× 108
345

= 0.55 tons CO/yr

If the facility had any operations in Maricopa County during the December–February CO season,
season-day emissions (lbs/day) were calculated as follows:
Season-day = total emissions attributable to activity in Maricopa County × 2,000 lbs
emissions
number of operating days in Maricopa County
ton
(lbs/day)
= 0.55 tons
× 2,000 lbs
108 days
ton
= 10.2 lbs CO/day

Table 3.3–7 summarizes the annual and season-day emissions for all ADEQ-permitted portable
sources that operated within Maricopa County at some point during 2002. Since no precise
location data was available, all emissions are conservatively assumed to have originated within
the CO nonattainment area, therefore emissions in Maricopa County and the CO nonattainment
area are equal.

2002 Carbon Monoxide Periodic Emission Inventory

41

Maricopa County, AZ

Table 3.3–7. Emissions from ADEQ-permitted portable sources, by permit type.
Annual emissions
Season-day
(tons/yr)
emissions (lbs/day)
Permit type
Asphalt batch
25.34
173.8
Concrete batch
7.25
15.8
Crushing/screening
105.56
696.5
Other
0.28
1.5
Totals:
138.43
887.6

3.3.4 Industrial processes not elsewhere classified (NEC)
Annual area-source emissions from other industrial processes not elsewhere classified (NEC)
were derived from annual emissions reports from permitted facilities. Other industrial processes
include a wide array of industrial activities that are often specific to the permitted facility that
reported the process. For this reason, it is assumed there are no significant emissions from other
industrial processes, other than those reported by permitted facilities on their annual emissions
reports. CO season-day emissions are calculated based on operating schedule information
provided by the facilities in their annual emissions report. All facilities that reported area-source
emissions from other industrial processes are located inside the CO nonattainment area, therefore
emissions for Maricopa County and the CO NAA are equal.
Table 3.3–8. Annual and season-day emissions from other industrial processes.
Annual emissions Season-day emissions
Geographic area
(tons/yr)
(lbs/day)
Maricopa County
0.98
7.5
CO NAA
0.98
7.5

3.3.5 Summary of all area-source industrial processes
Table 3.3–9 provides a summary of annual and season-day emissions from all industrial
processes.
Table 3.3–9. Summary of annual and season-day area source industrial processes.
Maricopa County
CO nonattainment area
Annual
Season-day
Annual
Season-day
emissions
emissions
emissions
emissions
Source category
(tons/yr)
(lbs/day)
(tons/yr)
(lbs/day)
Chemical manufacturing
0.07
0.5
0.07
0.5
Commercial cooking
273.50
1,502.8
268.28
1,474.1
State-permitted portable sources
138.43
887.6
138.43
887.6
Industrial processes NEC
0.98
7.5
0.96
7.5
Totals:
412.98
2,398.4
407.74
2,369.6

2002 Carbon Monoxide Periodic Emission Inventory

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Maricopa County, AZ

3.4

Waste treatment and disposal

3.4.1

On-site incineration

This section includes emissions from on-site industrial incinerators, primarily burn-off ovens
used to reclaim electric wire or other materials. Emissions from human and animal crematories
are addressed in Section 3.5.2. There were no incinerators at residential (e.g., apartment complexes) or commercial/institutional facilities (e.g., hospitals, service establishments) in operation
during 2002.
Emissions from on-site incineration were determined from annual emission inventory reports.
Of the four incinerators under permit in 2002, two were surveyed and reported annual emissions.
As all four facilities are roughly similar in terms of capacity, these survey results were doubled
to estimate total annual and season-day emissions from all four incinerators in Maricopa County.
All four facilities are located within the CO nonattainment area, thus total emissions for the
county and NAA are equal.
Table 3.4–1. Annual and season-day emissions from on-site incineration.
Annual emissions
Season-day
Geographic area
(tons/yr)
emissions (lbs/day)
Maricopa County
0.59
4.5
CO NAA
0.59
4.5

3.4.2 Open burning
Emissions from controlled open burning are regulated by MCESD Rule 314, which requires a
burn permit for open burning in Maricopa County. Burn permits are issued primarily for purposes of agricultural ditch bank and fencerow burning, tumbleweed burning, land clearance, air
curtain destructor burning of trees, and fire fighting training. Maricopa County’s burn permit
data base was used to identify all burn permits issued during 2002. A total of 140 permits were
issued during the year; however, not all permit applications contained the information needed to
calculate emissions. Where data were missing, activity data for each permit category was grown
from those permits that contained information, as follows:
Total activity =

∑ activity reported × number of permits with activity data
total number of permits issued

Example:
Total ditch 85 ditchbank/fencerow burn permits issued
= 973,885 linear ft ×
= 2,854,491 linear ft
bank/fencerows
29 permits with quantitative data

Reported and estimated activity data for each open burning category are summarized in Table
3.4–2. Permits issued for fire fighting training are addressed in Section 3.5.1.2, Structure fires.

2002 Carbon Monoxide Periodic Emission Inventory

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Maricopa County, AZ

Table 3.4–2. 2002 Maricopa County burn permit activity data.
Number of
permits with
Unit of
Total reported
activity data
measure
activity
Category
Ditchbank/fencerow Linear ft
973,885
29
Land clearance
Acres
1,345
17
Land clearance
Piles
69
8
Air curtain
Trees
200
1
Tumbleweeds
Piles
9
3

Total
permits
issued
85
34
34
2
8

Activity grown to
total number of
permits issued
2,854,491
2,690
293
400
24

The above activity data were converted to tons material burned using fuel loading factors from
AP-42, Table 2.5-5 (US EPA, 1992). The emission and loading factors used are shown in Table
3.4–3.
Table 3.4–3. Emission and fuel loading factors for open burning.
CO emission factor
Category
(lb/ton burned)
Weeds, unspecified
85
Russian Thistle (tumbleweeds)
309
Orchard Crops: Citrus
81

Fuel loading factors
3.2 tons/acre
0.1 tons/acre
1.0 tons/acre

The following assumptions were made based on previous MCESD emission inventory work:
• Ditch banks and fence rows in Maricopa County average 7 feet in width and are burned
twice per year (MCESD, 1999).
• A pile of tumbleweeds 15 feet in diameter and 5 feet high weighs 200 lbs (MCESD,
1993). This is equivalent to the AP-42 fuel loading factor for tumbleweeds – 0.1
tons/acre.
• The estimated weight of a mature, partially dried citrus tree, including trunk, limbs and
bulk of root is 500 lbs per tree (MCESD, 1993).
To calculate the annual amount of material burned on ditch banks and fence rows in Maricopa
County, MCESD estimated the area burned and then applied AP-42 fuel loading factor. The tons
of material burned in ditch banks and fence rows in Maricopa County were estimated as follows:
Material burned
for ditch bank and
fence row burning

= 2,854,491 ft length × 7 ft width × 3.2 tons/acre × 2 times/year
43,560 ft2 / acre
= 2,936 tons material burned/yr

Activity data for the other categories were similarly converted to material burned using AP-42
fuel loading factors.
Annual emissions were then calculated by multiplying the amount of material burned by
emission factors listed in AP-42 (Table 3.4–3). To account for unpermitted illegal outdoor
burning, the county’s Air Quality Complaint data base was examined, which indicated 65 illegal
outdoor open burning complaints (mostly residential) and 6 issued Notices of Violation. All
calculated emissions estimates were thus increased by 10 percent, as a conservative estimate.

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Maricopa County, AZ

Annual CO emissions from
= Total material burned
ditchbank and fence row burning
= 2,936 tons

× emission factor

× unit conversion factor

× 85 lbs/ton

× 1 ton / 2,000 lbs

= 124.78 tons CO/yr
Total annual CO emissions
= Calculated emissions from permit data + unpermitted burning adjustment factor
including unpermitted burning
= 124.78 tons/yr + (10% x 124.78)
= 137.25 tons CO/yr

Table 3.4–4 summarizes the annual emissions for Maricopa County from each open burning
category.
Table 3.4–4. Annual emissions from open burning (tons/yr).
CO emissions
(tons/yr)
Category
Ton-equivalents
Ditchbank/fencerow
2,935.7
137.25
Land clearance
9,545.5
446.25
Air curtain
100.0
4.46
Tumbleweeds
2.4
0.41
Total:
588.36

Annual emissions for the nonattainment area are calculated by multiplying the percentage of
agricultural and/or vacant land use located in the CO nonattainment area by the Maricopa County
emission totals. (See Section 1.5.2 for a discussion of the land-use data used.) Table 3.4–5
summarizes the annual emissions for the CO nonattainment area.
Table 3.4–5. Surrogate land-use classes, ratios and annual emissions from open burning in the CO NAA.
Surrogate land-use
2000 NAA:county
Category
category
land-use ratio
Emissions (tons/yr)
Ditchbank/fencerow
Agriculture
44.53 %
61.12
Land clearance
Vacant
15.62 %
69.70
Air curtain
agriculture and vacant
19.53 %
0.87
Tumbleweeds
agriculture and vacant
19.53 %
0.08
Total:
131.77

Ditch bank/fence row burning is not allowed from November to February, therefore daily emissions during the CO season are zero. For the other burning categories, it was assumed that open
burning occurs 5 days per week (most burn permits are issued for weekdays but permits may be
issued on weekends depending on circumstances) and open burning occurs evenly during the CO
season months (November – December). A seasonal adjustment factor was derived as follows:
Seasonal adjustment factor

Example:
Seasonal adjustment factor
for tumbleweed burning

= # of permits issued Nov. – Dec. for the category
total # of permits issued in 2002 for the category

= 3 permits issued during Nov. – Dec. for tumbleweed burning
8 total permits issued in 2002 for tumbleweed burning
= 37.50 %

2002 Carbon Monoxide Periodic Emission Inventory

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CO season-day emissions for Maricopa County are derived using the following formula:
CO season-day emissions = (annual CO emissions lbs) × (seasonal adjustment factor)
from tumbleweed burning
(# of burn days/week) × (# of season weeks/year)
=

820 lbs × 0.3750
5 days/wk × 13 wks/yr

= 4.73 lbs CO/day

CO season-day emissions for the nonattainment area are calculated by multiplying the percentage of agricultural and/or vacant land use located in the nonattainment area (listed in Table 3.4–
5) by the total County season-day emissions. Table 3.4–6 summarizes the CO season-day
emissions from open burning for both Maricopa County and the CO nonattainment area.
Table 3.4–6. Season-day emissions (lbs/day) from open burning.
Maricopa County
CO nonattainment area
Category
(lbs/day)
(lbs/day)
Ditchbank/fencerow
0.0
0.0
Land clearance
3,634.6
567.7
Air curtain
0.0
0.0
Tumbleweeds
4.7
0.9
Totals:
3,639.3
568.6

3.4.3

Landfills

Emissions from municipal solid waste (MSW) landfills come from uncontrolled landfill gas
emissions as well as combustion from control measures, such as flares. Total emissions were
calculated from annual emissions inventory reports from all landfills located within the county.
Two MSW landfills (Butterfield Station and Allied Waste Industries Southwest Regional
Facility) are considered point sources and are reported in Chapter 2. All other MSW landfills are
reported here as area source landfills.
Since there are no area-source landfills located outside the CO nonattainment area, total emission
values for the county and the CO nonattainment area are equal. Season-day emissions were
calculated based on reported activity data (days per week) for each individual process, and then
summed. Nearly all processes reported operating on a 7 day week. Emissions within the CO
nonattainment area were identified using information on the location of each permitted facility.
Annual and daily emissions are shown in Table 3.4–7.
Table 3.4–7. Annual and season-day emissions from landfills.
Annual emissions Season-day emissions
Geographic area
(tons/yr)
(lbs/day)
Maricopa County
27.35
150.3
CO NAA
27.35
150.3

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3.4.4

Summary of all area-source waste treatment and disposal

Table 3.4–8. Summary of annual and season-day emissions from waste treatment and disposal.
Maricopa County
CO nonattainment area
Annual
Season-day
Annual
Season-day
emissions
emissions
emissions
emissions
Source category
(tons/yr)
(lbs/day)
(tons/yr)
(lbs/day)
On-site incineration
0.59
4.5
0.59
4.5
Open burning
588.36
3,639.3
131.77
568.6
Landfills
27.35
150.3
27.35
150.3
Totals:
616.30
3,794.2
159.71
723.5

3.5

Miscellaneous area sources

3.5.1

Other combustion

3.5.1.1 Wildfires and brush fires
The Arizona Department of Environmental Quality, in cooperation with the United States Forest
Service, reported that one wildfire burned 1000 acres in the Tonto National Forest in July 2002.
The wildfire occurred within Maricopa County but outside of the nonattainment area. ADEQ
also reported that negligible prescribed fires occurred in Maricopa County in 2002.
In addition, 2002 survey results from Maricopa County fire departments, the Bureau of Land
Management, and the Arizona State Land Department were used to calculate emissions from
brush fires. In some cases, the survey results included limited information on the average size of
fires. Thus, when acreage data was incomplete or unclear, each reported brush fire was assumed
to be equal to 0.1 acres. Survey results are included in Appendix 3.1. It was estimated that
7,054 brush fires occurred in Maricopa County in 2002 and burned approximately 1,656.5 acres.
Wildfire emission factors and fuel loading factors were obtained from the Western Regional Air
Partnership’s (WRAP) 1996 Fire Emission Inventory (WGA/WRAP, 2002), while brush fire
emission factor and fuel loading factors were obtained from AP-42 (US EPA, 1992). Both are
listed in Table 3.5–1. Estimates of the material burned in are derived by multiplying the number
of acres burned by the appropriate fuel loading factor. For wildfires, a “combustive efficiency”
factor of 90% is included in the calculation to reflect the fact that not all available material (fuel)
is consumed in a wildfire (WGA/WRAP, 2002).
Table 3.5–1. Emission and fuel loading factors for wildfires and brush fires.
Number Fuel loadof acres
ing factor
Fires
CO emission factor
reported
burned (tons/acre)
(lbs/ton burned)
Type of fire
Wildfire (Calif. chaparral)
1
1,000
19.5
289
Brush fire (weeds)
7,054
1656.5
3.2
85

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Annual emissions from wildfires in Maricopa County were calculated as follows:
Annual CO emissions
from wildfires in
Maricopa County

=acres burned × fuel loading factor × combustive efficiency × emission factor (lbs/ton)
2,000 lbs/ton
=1,000 acres burned × 19.5 tons/acre × 90% × 289 lbs/ton
2,000 lbs/ton
= 2,535.98 tons CO/yr

Because the 1,000-acre wildfire occurred in the Tonto National Forest, which is located outside
of the nonattainment area, emissions from wildfires within the nonattainment area were
determined to be zero. However, annual emissions from brush fires for the nonattainment area
were calculated by multiplying the Maricopa County annual emissions by the percentage of
vacant land located in the CO nonattainment area (15.62%), as shown in Table 3.5–2. (See
Section 1.5.2 for a discussion of the land-use data used.)
Annual CO emissions from
= Annual CO emissions from
brush fires within the CO NAA
brush fires, County total
= 225.28 tons/yr
= 35.19 tons CO/yr

× Percentage of vacant land
within the NAA
× 15.62 %

Table 3.5–2. Annual emissions from wildfires and brush fires (tons/yr).
Type of fire
Maricopa County
CO nonattainment area
Wildfire
2,535.98
0.00
Brush fire
225.28
35.19
Totals:
2,761.25
35.19

Because the 1,000-acre wildfire occurred in July 2002 and the CO season is November through
January, it was presumed that no wildfires occurred during the CO season; therefore season-day
emissions from wildfires were zero. It was assumed that brush fires occur evenly throughout the
year. Thus, CO season-day emissions from brush fires were derived by dividing the annual
emissions from brush fires for Maricopa County and the nonattainment area by a 365 days/yr, as
follows:
Season-day CO emissions
emissions from brush fires
in Maricopa County

= 225.28 tons/yr
365 days/yr

× 2,000 lbs/ton

= 1,234.41 lbs/day
Table 3.5–3. Season-day emissions from wildfires and brush fires (lbs/day).
Type of fire
Maricopa County
CO nonattainment area
Wildfire
0.0
0.0
Brush fire
1,234.4
192.8
Totals:
1,234.4
192.8

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3.5.1.2 Structure fires
2002 structure fire data were obtained by surveying fire departments in Maricopa County and by
querying Maricopa County’s burn permit data base. The fire departments surveyed reported
3,597 structure fires in Maricopa County in 2002. The list of fire departments surveyed and
survey results are contained in Appendix 3.1. Eleven open burn permits were issued in 2002 for
fire training; these were included in the total number of estimated structure fires for 2002. It was
estimated that 3,608 structure fires occurred in Maricopa County in 2002.
Estimates of the material burned in a structure fire were determined by multiplying the number
of structure fires by a fuel loading factor of 1.15 tons of material per fire, which factors in
percent structural loss and content loss (US EPA, 2001c). Tons of material burned were
estimated as the follows:
Material burned in
= 3,608 fires
× 1.15 tons/fire
structure fires (tons/yr)
= 4,149.2 tons material burned/year
Table 3.5–4. Estimated material burned, emission and fuel loading factors for structure fires.
Structure
Fuel loading
Material burned
CO emission
fires reported
factor (tons/fire)
(tons)
factor (lbs/ton)
3,608
1.15
4,149.20
60

Annual emissions were then calculated by multiplying the amount of material burned by the
emission factors listed in Table 3.5–4 (US EPA, 2001c), as follows:
Annual CO emissions = Quantity of material burned × emission factor × unit conversion factor
from structure fires
Maricopa County
= 4,149.20 tons
× 60 lbs/ton
× (1 ton/2,000 lbs.)
= 124.48 tons CO/yr

Annual emissions for the CO nonattainment area were derived by multiplying Maricopa County
annual emissions by the percentage of total residential population within the CO nonattainment
area (98.06%), as shown in the example below. See Section 1.5.1 for a discussion of the
population data used.
Annual CO emissions
within the CO NAA

= annual CO emissions
for Maricopa County

× percentage residential
population within the NAA

= 124.48 tons/year

× 98.06 %

= 122.06 tons CO/yr

It was assumed that structure fires occur 7 days a week; however, structure fires vary seasonally
and may increase during cold weather. Because local season-specific data were not available
from the fire department surveys, seasonal occurrences of residential and non-residential
structure fires reported by the Federal Emergency Management Agency (FEMA) were used to
derive a seasonal adjustment factor for the CO season (US EPA, 2001c). FEMA reported that
29.6% of residential structure fires and 24.5% of non-residential structural fires occurred during
2002 Carbon Monoxide Periodic Emission Inventory

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Maricopa County, AZ

November, December, and January 1994. Thus, an average occurrence of 27.05% [(29.6% +
24.5%) ÷ 2] was used as a seasonal adjustment factor to estimate CO season-day emissions.
CO season-day emission for Maricopa County were derived using the following formula:
CO season-day emissions = annual CO emissions (lbs) × seasonal adjustment factor (%)
from structure fires in
7 days/wk × 13 weeks/yr
Maricopa County
= 248,960 lbs × 27.05%
91
= 740.04 lbs CO/day

CO season-day emissions for the nonattainment area are calculated by multiplying the Maricopa
County season-day emissions by the percentage of total residential population within the CO
nonattainment area (98.06%). Results are shown in Table 3.5–5.
Table 3.5–5. Annual and season-day emissions from structure fires.
Annual emissions Season-day emissions
Geographic area
(tons/yr)
(lbs/day)
Maricopa County
124.48
740.0
CO NAA
122.06
725.7

3.5.1.3 Vehicle fires
2002 vehicle fire data were obtained by surveying fire departments in Maricopa County. The
fire departments surveyed reported 5,316 vehicle fires (4 boat fires were included in vehicle
fires) in Maricopa County in 2002. The list of fire departments surveyed and survey results are
presented in Appendix 3.1.
Annual emissions from vehicle fires are calculated by first multiplying the number of vehicle
fires by a fuel loading factor of per vehicle fire to estimate the annual amount of material burned
in vehicle fires. The amount of annual material burned in vehicle fires is then multiplied by
emission factors for open burning of automobile components from AP-42 as listed in Table 3.5–
6 (from US EPA, 1992).
Annual CO emissions
from vehicle fires

= annual number × fuel loading factor × emission factor × unit conversion factor
of vehicle fires
= 5,316
× 0.25 tons/vehicle
= 83.06 tons CO/yr

× 125 lbs/ton

× (1 ton / 2,000 lbs)

Table 3.5–6. Estimated material burned, emission and fuel loading factors for vehicle fires.
Vehicle fires
Fuel loading
Material
CO emission
reported
factor (tons/fire)
burned (tons)
factor (lbs/ton)
5,316
0.25
1,329
125

Annual emissions for the CO nonattainment area were derived by multiplying Maricopa County
annual emissions by the percentage of total residential population within the CO nonattainment
area (98.06%). See Section 1.5.1 for a discussion of the population data used.
2002 Carbon Monoxide Periodic Emission Inventory

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Maricopa County, AZ

It was assumed that vehicle fires occur evenly throughout the year. Thus, CO season-day emissions were derived by dividing the Maricopa County and nonattainment area annual emissions
by 365 days/year. The results are shown in Table 3.5–7 below.
Table 3.5–7. Annual and season-day emissions from vehicle fires.
Annual emissions Season-day emissions
Geographic area
(tons/yr)
(lbs/day)
Maricopa County
83.06
455.1
CO NAA
81.45
446.3

3.5.1.4 Engine testing
Annual emissions from engine testing facilities were derived from annual emission reports from
permitted sources that were not considered point sources in this inventory. It was assumed that
there were no significant unpermitted sources within Maricopa County. Season-day emissions
were calculated based on operating schedule information provided in the facilities’ annual emission reports. Since all facilities considered in this section are located within the CO nonattainment area, total emission values for the county and the CO NAA are equal. Results are
shown in Table 3.5–8.
Table 3.5–8. Annual and season-day emissions from engine testing.
Annual emissions Season-day emissions
Geographic area
(tons/yr)
(lbs/day)
Maricopa County
3.67
99.9
CO NAA
3.67
99.9

3.5.2

Health services: crematories

Emissions from human and animal crematories were calculated by the “scaling up” method as
described in EPA emission inventory guidance (US EPA, 2001a). This method combines
detailed emissions data from a subset of sources, and county-level employment data from the US
Census Bureau (2003a) to develop a per-employee emission factor that is then used to estimate
emissions from all sources in an industry category.
The most recent data from the Census’ County Business Patterns (CBP), for 2001 employment,
were used. CBP employment data for NAICS code 81222 (cemeteries and crematories)
indicated 683 employees in this industry in Maricopa County. This employment estimate is used
to “scale up” emissions reported from those facilities surveyed in 2002 as follows:
Total area-source = Emissions from surveyed area sources × Total area-source employment
CO emissions
Employment at surveyed area sources
from crematories
= 0.17 tons/yr
× 683 employees
110
= 1.06 tons CO/yr

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Maricopa County, AZ

Season-day emissions are calculated based on the operating schedule data reported by surveyed
facilities. From annual emission surveys, the modal values were identified for two items:
days/week and seasonal activity as a percentage of annual activity. This data was used to
calculate typical season-day emissions as follows:
Season-day CO
emissions from
crematories

=Annual emissions (tons/yr) × seasonal %
Days/week × Weeks/season
=

1.06 × 25%
5 × 13

× 2,000 lbs
ton

× 2,000

= 8.2 lbs CO/day

As all facilities addressed in this source category are located within the CO nonattainment area,
emission totals for both areas are equal. Annual and daily emissions are shown in Table 3.5–9.
Table 3.5–9. Annual and season-day emissions from crematories.
Annual emissions
Season-day
Geographic area
(tons/yr)
emissions (lbs/day)
Maricopa County
1.06
8.2
CO NAA
1.06
8.2

3.5.3

Accidental releases

As part of its air quality permit compliance program, MCESD keeps an “upset log” for each
calendar year, that records excess emissions and accidental releases at permitted facilities.
Annual emissions inventory reports also provide for recording of accidental releases. Data from
these two sources documented the release of 3.47 tons of CO for the year 2002. Season-day
emissions of CO are assumed to be zero, as no recorded releases occurred during the CO season.
Emissions in the CO nonattainment area are calculated based on locations of facilities that
reported releases. In 2002, all recorded releases occurred outside the CO NAA.
Table 3.5–10. Annual and season-day emissions from accidental releases.
Annual emissions
Season-day
Geographic area
(tons/yr)
emissions (lbs/day)
Maricopa County
3.47
0.0
CO NAA
0.00
0.0

3.5.4

Summary of all miscellaneous area sources

Table 3.5–11. Summary of annual and season-day emissions from all miscellaneous area sources.
Maricopa County
CO nonattainment area
Annual emissions
Season-day
Annual emissions
Season-day
Source category
(tons/yr)
emissions (lbs/day)
(tons/yr)
emissions (lbs/day)
Wildfires and brushfires
2,761.25
1,234.4
35.19
192.8
Structure fires
124.48
740.0
122.06
725.7
Vehicle fires
83.06
455.1
81.45
446.3
Engine testing
3.67
99.9
3.67
99.9
Crematories
1.06
8.2
1.06
8.2
Accidental releases
3.47
0.0
0.00
0.0
Totals:
2,976.99
2,537.6
243.43
1,472.79
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3.6

Summary of area source emissions

Table 3.6–1 summarizes the total annual and CO season-day emissions from all area sources
addressed in this chapter for both Maricopa County and the CO nonattainment area.
Table 3.6–1. Summary of annual and season-day area source emissions, by source category.
Maricopa County
CO nonattainment area
Annual
Season-day
Annual
Season-day
emissions
emissions
emissions
emissions
Source category
(tons/yr)
(lbs/day)
(tons/yr)
(lbs/day)
Fuel combustion:
Industrial natural gas
68.95
505.5
67.64
495.9
Industrial fuel oil
166.66
1,068.3
163.48
1,047.9
Commercial/institutional natural gas
655.00
5,594.0
643.80
5,498.4
Commercial/institutional fuel oil
386.20
3,465.9
379.59
3,406.6
Residential natural gas
328.39
2,632.9
322.41
2,585.0
Residential wood
3,212.28
53,313.6
3,153.82
52,343.3
Residential fuel oil
0.23
3.8
0.23
3.7
Total, all fuel combustion:
4,817.71
66,584.1
4,730.96
65,380.8
Industrial processes:
Chemical manufacturing
Commercial cooking
State-permitted portable sources
Industrial process NEC
Total, all industrial processes:

0.07
273.50
138.43
0.98
412.98

0.5
1,502.8
887.6
7.5
2,398.4

0.07
268.28
138.43
0.96
407.74

0.5
1,474.1
887.6
7.4
2,369.6

Waste treatment/disposal:
On-site incineration
Open burning
Landfills
Total, all waste treatment/disposal:

0.59
588.36
27.35
616.30

4.5
3,639.3
150.3
3,794.2

0.59
131.77
27.95
159.71

4.5
568.6
150.3
723.5

2,761.25
124.48
83.06
3.67
1.06
3.47
2,976.99
8,823.98

1,234.4
740.0
455.1
99.9
8.2
0.0
2,537.6
75,314.2

35.19
122.06
81.45
3.67
1.06
0.00
243.43
5,541.86

192.8
725.7
446.3
99.9
8.2
0.0
1,472.8
69,946.8

Miscellaneous area sources:
Wildfires and brush fires
Structure fires
Vehicle fires
Engine testing
Health Services: crematories
Accidental releases
Total, all misc. area sources:
Total, all area sources:

3.7

Quality assurance / quality control procedures

Quality assurance and quality control (QA/QC) activities for the area source emissions inventory
were driven by the goal of creating a comprehensive, accurate, representative and comparable
inventory of area source emissions for Maricopa County and the nonattainment area. During
each step of creating, building and reviewing the area source emissions inventory, quality checks
and assurances were performed to establish confidence in the inventory structure and data.
Area source categories were selected for inclusion in the inventory based on the latest Emission
Inventory Improvement Program (EIIP) guidance available. EPA’s guidance for area source
categories included in the draft 2002 National Emission Inventory (NEI) was also evaluated, as
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Maricopa County, AZ

area source emissions from this inventory will be submitted to EPA for the 2002 NEI. The list of
area source categories developed based on these guidance documents was modified to fit the
characteristics of Maricopa County, with some area source categories determined to be insignificant (such as industrial coal combustion and oil and gas production). The 1999 Maricopa
County Periodic Ozone and Carbon Monoxide Emission Inventories and other regional emission
inventories were also consulted to confirm the completeness of the area source categories chosen
for inclusion.
Data for area source emission calculations were gathered from a wide universe of resources.
Whenever applicable, local surveyed data (such as annual emissions report) was used as this data
best reflects activity in the county and the nonattainment area. When local data was not available, state data from Arizona State agencies (such as the Arizona Department of Transportation)
and regional bodies (such as the Western Regional Air Partnership {WRAP}) were used.
National level data (such as the US Census Bureau) was used when no local, state or regional
data was available. In addition, the most recent EIIP guidance for area sources was consulted for
direction in determining the most relevant data source for use in emissions calculations.
Emissions calculations for area sources were performed by three air quality planners and one unit
manager. All area source emission estimates were calculated in spreadsheets to ensure the calculations could be verified and reproduced. Whenever possible or available, the “preferred
method” described in the most recent EIIP guidance documents for area sources was used to
calculate emissions. Emissions were estimated using emission factors from EIIP guidance, AP42, and local source testing. Local seasonal and activity data were used when available, with
EPA and EIIP guidance used when no local seasonal or activity data existed. All calculations
were evaluated to ensure that emissions from point sources were not being double-counted and to
determine if rule effectiveness applied.
Once area source emission estimates had been produced, several quality control checks were
performed to substantiate the calculations. Most area source calculations were peer-reviewed by
two other planners, with all area sources being reviewed by at least one other planner. Peer
review ensured that all emission calculations were reasonable and could be reproduced.
Sensitivity analyses and computational method checks were performed on area sources when
emissions seemed to be outside the expected ranges. When errors were found, the appropriate
changes were made by the author of the calculations to ensure consistency of the emissions
calculations. The peer-reviewed emissions estimates were combined into a draft area source
chapter. This draft chapter was read through in its entirety by the unit manager and the three air
quality planners for final review, with any identified errors corrected by the author of the section.
The draft version of the area source chapter was sent to the Arizona Department of Environmental Quality, the Arizona Department of Transportation, and the Maricopa Association of
Governments for a quality assurance review. These agencies provided comments which were
addressed and incorporated into the final area source chapter. Further quality analysis was
performed by inputting the emission estimates into EPA’s “QA/QC basic format and content
checker”, prior to submitting the data to the 2002 NEI.
The QA/QC activities described here have produced high levels of confidence in the area source
emissions estimates detailed in this chapter, and represent the best efforts of the inventory
preparers.
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3.8

References

ASU, 2003. Heating Degree Days: Phoenix. Office of Climatology, Arizona State University,
Tempe AZ. Internet address: http://www.commerce.state.az.us/doclib/ENERGY/
Degreedays.pdf.
Harris InfoSource, 2003. Selectory CD-ROM Database of Arizona Businesses. March 2003.
MCESD, 1993. 1990 Base Year Ozone Emission Inventory for Maricopa County, Arizona,
Nonattainment Area, Draft Submittal, Maricopa County Environmental Quality &
Community Services Agency, March 1993.
MCESD, 1999. 1999 Periodic Ozone Emissions Inventory for the Maricopa County, Arizona
Nonattainment Area, Maricopa County Environmental Services Department, November
2001, Revised August 2002.
US Census Bureau, 2003a. 2001 County Business Patterns (CenStats Databases). Internet
address: http://censtats.census.gov/cbpnaic/cbpnaic.shtml.
US Census Bureau, 2003b. 2001County Business Patterns (NAICS). Internet address:
http://censtats.census.gov/ cgi-bin/cbpnaic/cbpsel.pl
US Census Bureau, 2003c. Profile of Selected Housing Characteristics: 2000. Census 2000
Summary File 3. Internet address: http://factfinder.census.gov/servlet/BasicFactsTable?
_lang=en&_vt_name=DEC _2000_SF3_U_DP4&_geo_id=05000US04013
US DOE, 2002a. US Dept. of Energy, Energy Information Administration. Adjusted Sales for
Commercial Use: Distillate Fuel Oil, Residual Fuel Oil, and Kerosene (Table 20). Internet
address: http://www.eia.doe.gov/pub/
oil_gas/petroleum/data_publications/fuel_oil_and_kerosene_sales/current/pdf/table20.pdf.
US DOE, 2002b. US Department of Energy, Energy Information Administration. Adjusted Sales
for Industrial Use: Distillate Fuel Oil, Residual Fuel Oil, and Kerosene (Table 21). Internet
address: http://www.eia.doe.gov/ pub/oil_gas/petroleum/ data_publications/
fuel_oil_and_kerosene_sales/current/pdf/table21.pdf.
US DOE, 2003. US Department of Energy, Energy Information Administration. State Energy
Data 2000 Consumption Tables, Table 8. Residential Energy Consumption Estimates, 1960–
2000, Arizona. Internet address: http://www.eia.doe.gov/emeu/states/sep_use/res/
use_res_az.html
US EPA, 1992. Compilation of Air Pollution Emission Factors (AP-42). Fifth Ed. Vol. I:
Stationary Point and Area Sources. Section 2.5: Open Burning. US Environmental
Protection Agency, Office of Air Quality Planning and Standards, Research Triangle Park,
NC.
US EPA, 1998. Compilation of Air Pollution Emission Factors (AP-42). Fifth Ed. Vol. I:
Stationary Point and Area Sources. Section 1.4: Natural Gas Combustion. US Environmental Protection Agency, Office of Air Quality Planning and Standards, Research Triangle
Park, NC. Internet address: http://www.epa.gov/ttn/chief/ap42/ch01/final/c01s04.pdf
US EPA, 2001a. Introduction To Area Source Emission Inventory Development. Emission
Inventory Improvement Program (EIIP) Vol. III, Chap. 1. Prepared by Eastern Research
Group, Revised Final, Jan. 2001. Internet address: http://www.epa.gov/ttn/chief/eiip/
techreport/volume03/iii01_apr2001.pdf
US EPA, 2001b. Residential Wood Combustion. Emission Inventory Improvement Program
(EIIP) Vol. III, Chap. 2. Revised Final, Jan. 2001. Prepared by Eastern Research Group, Inc.
for the Area Source Committee, EIIP. Internet address: http://www.epa.gov/ttn/chief/eiip/
techreport/volume03/iii02_apr2001.pdf.

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Maricopa County, AZ

US EPA, 2001c. Structure Fires. Emission Inventory Improvement Program (EIIP) Vol. III,
Chap. 18. Revised Final, Jan. 2001. Prepared by Eastern Research Group, Inc. for the Area
Source Committee, EIIP. Internet address: http://www.epa.gov/ttn/chief/eiip/techreport/
volume03/iii18_apr2001.pdf.
US EPA, 2004. Documentation for the 2002 Preliminary Non point Source National Emission
Inventory for Criteria and Hazardous Air Pollutants (Jan. 2004 Version). Prepared by E.H.
Pechan & Associates, Inc. for Emission Factor and Inventory Group. Internet address:
ftp://ftp.epa.gov/pub/emisinventory/prelim2002nei/nonpoint/documentation
USFS, 1993. Cliff Dills, US Forest Service, Payson Ranger Station, Payson AZ, pers. comm.
WGA/WRAP 2002. Draft Final Report – 1996 Fire Emission Inventory, Western Governors
Association/Western Regional Air Partnership, prepared by Air Science, Inc. Project 178-1,
December 2002, pp. 48–51.

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Maricopa County, AZ

4.

Nonroad Mobile Sources

4.1

Introduction

Nonroad mobile sources are defined as those sources that move or are moved within a 12-month
period and are not licensed or certified as highway vehicles. Nonroad mobile sources are
vehicles and engines that fall under the following categories:
•
•
•
•
•
•
•
•
•
•
•
•
•

Agricultural equipment, such as tractors, combines and balers;
Airport ground support equipment, such as baggage tugs, and terminal tractors;
Commercial equipment, such as generators and pumps;
Industrial equipment, such as forklifts and sweepers;
Construction and mining equipment, such as graders, back hoes and trenchers;
Lawn and garden equipment, such as leaf blowers and lawn mowers;
Logging equipment, such as shredders and large chain saws;
Pleasure craft, such as power boats and personal watercraft;
Railway maintenance equipment, such as rail straighteners;
Recreational equipment, such as all-terrain vehicles and off-road motorcycles;
Underground mining and oil field equipment, such as mechanical drilling engines (not
present in Maricopa County);
Aircraft, such as jet and piston engines; and
Locomotives, such as switching and line haul trains.

Emission calculations for most nonroad mobile sources are derived from a Maricopa County
nonroad emission inventory of certain visibility-impairing pollutants (PM10, PM2.5, NOx and
SOx) developed by ENVIRON International Corp. for calendar year 2002 (ENVIRON et al.,
2003). ENVIRON prepared the inventory for use and review by the Cap and Trade Oversight
Committee (CTOC) formed by the Arizona Department of Environmental Quality (ADEQ). In
the inventory prepared for the Cap and Trade Committee, EPA’s NONROAD2002 model from
EPA (Core Version 2.1d March, 2002) was used to estimate emissions for all categories except
aircraft and locomotives. Nonroad modeling for the ENVIRON inventory was based on recent
NONROAD modeling performed for the Western Regional Air Partnership (WRAP) for use in
the development of a regional haze rule.
Since the modeling done for the CTOC was only annual totals for Maricopa County, additional
work was needed to develop estimates for the CO nonattainment area and for an average CO
season day. Emission calculations for this report differ from the CTOC work in one major area:
emission estimates prepared for the CTOC were derived from season average weekday calculations, which were then multiplied by the number of days in each season to produce season
totals, and then summed to produce annual emission totals. This approach assumes that activity
levels of nonroad equipment are the same on weekdays and weekends.
For this report, ENVIRON re-ran the NONROAD2002 model to produce season totals, which
are then summed to produce annual emission totals. The revised method used for this report
results in annual emissions levels that are about 15% less than the method used for the CTOC
inventory. The method used by ENVIRON for this report takes into account the different

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Maricopa County, AZ

activity levels experienced on weekdays versus weekends, which explains the lower annual
emissions.
The NONROAD model define four seasons as follows: spring – March through May, summer –
June through August, fall – September through November, and winter – December through
February. Since the gasoline oxygen content in Maricopa County changes on September 30,
emissions from the fall quarter were calculated for each month separately, and then summed.
Seasonal emissions totals are then summed to produce annual emission totals.
The methods used to estimate CO season-day emissions are described in each section of this
chapter. Emission estimates from the winter season (December–February) are assumed to
represent emissions in the CO season (November–January).
Temperature and fuel-related inputs are required for the operation of the NONROAD2002
model. The inputs listed below were used by ENVIRON after ADEQ review:
Fuel volatility (Reid Vapor Pressure [RVP]), psi: 9.0 in winter, 8.1 in spring, 7.8 in summer and
fall.
• Gasoline oxygen content (weight %): 3.36 from October through February, 0.0 otherwise.
• Gasoline sulfur content (ppm): 179 in fall and winter, 115 in spring and summer.
• Diesel sulfur content (ppm): 310 all seasons.
• Temperatures (minimum/average/maximum °F): 39/55/65 winter, 53/72/83 spring,
78/94/104 summer, 57/78/87 fall.
EPA recommends adjusting default NONROAD2002 model values (such as equipment population, activity levels of equipment, growth factors, etc.) where local data is available, as the
default values in the model are derived from national averages. ENVIRON adjusted the
NONROAD2002 model defaults in the following manner:
•

•

•

The NONROAD model uses 1996 as a base year, and then projects emissions for any
given year based on growth factors inherent in the model. The default growth factors in
the model were zeroed out to reflect base year 1996 equipment population numbers.
Arizona-specific growth factors developed for WRAP were then applied to the
NONROAD2002 model outputs to produce 2002 year population numbers and associated
emissions.
Equipment population numbers and activity levels for commercial lawn and garden
equipment were adjusted based on survey results of the commercial lawn and garden
industry performed by ENVIRON as part of the CTOC work. Survey results show that
for most categories of lawn and garden equipment, the equipment populations for
Maricopa County are significantly lower than EPA default values, while the average
annual hours of operation for most equipment types are slightly higher than EPA's values.
Using these new local data results is a considerable decrease in emissions from this
category, compared with earlier results using EPA default data.
Equipment population numbers and activity levels for airport ground support equipment
were adjusted based on Maricopa County-specific data provided by the Maricopa
Association of Governments (MAG) for the CTOC inventory.

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Spatial allocation factors were developed, based on EPA guidance documents, to apportion
nonroad emissions to the CO nonattainment area. The approaches used are described in each
section of this chapter.
Temporal allocations (used to calculate CO season-day emissions) for nonroad equipment
categories modeled in the NONROAD2002 model come from EPA recommendations on
weekday and weekend day activity levels for each nonroad equipment category (US EPA, 1999).
Table 4.1–1 below lists the weighted activity level allocation fractions for each equipment class
for weekdays and weekend days. For this report, the most conservative (highest) allocation
fraction in each nonroad equipment class was used to calculate season-day emissions.
Table 4.1–1. Default weekday and weekend day activity allocation fractions.
Equipment category
Weekday
Weekend day
Agricultural
0.1666667
0.0833334
Airport ground support
0.1428571
0.1428571
Commercial
0.1666667
0.0833334
Construction and mining
0.1666667
0.0833334
Industrial
0.1666667
0.0833334
Lawn and garden (residential)
0.1111111
0.2222222
Lawn and garden (commercial)
0.1600000
0.1000000
Logging
0.1666667
0.0833334
Pleasure craft
0.0600000
0.3500000
Railway maintenance
0.1800000
0.0500000
Recreational
0.1111111
0.2222222

4.2

Agricultural equipment

Annual emissions from agricultural equipment in Maricopa County were calculated using EPA’s
NONROAD2002 model, as discussed above. Emissions are reported by engine type: gasoline 2stroke, gasoline 4-stroke, diesel, compressed natural gas (CNG), and liquid petroleum gas (LPG).
Emissions from CNG and LPG equipment are reported in the gasoline 4-stroke category, as total
emissions from these engine types were either trivial or none. County-wide results are shown in
Table 4.2–1.
Table 4.2–1. Annual emissions from agricultural equipment in Maricopa County.
Source ClassifiCO emissions
cation Code (SCC) Engine type
(tons/year)
2260005000
Gasoline 2-stroke
2.12
2265005000
Gasoline 4-stroke
355.26
2270005000
Diesel
275.58
Total:
632.96

CO nonattainment area annual emissions were calculated based on EIIP guidance (US EPA,
2002) which recommends using the ratio of agricultural land inside the nonattainment area
(185,029 acres) to agricultural land inside the county (415,473 acres). See Section 1.5.2 for a
discussion of land-use data used.
CO nonattainment area emissions = County CO emissions
from agricultural equipment
= 632.96 tons
= 281.86 tons CO/yr
2002 Carbon Monoxide Periodic Emission Inventory

59

× Agricultural land-use allocation factor
× 44.53%

Maricopa County, AZ

Table 4.2–2. Annual emissions from agricultural equipment in the CO nonattainment area.
CO emissions
SCC
Engine type
(tons/year)
2260005000 Gasoline 2-stroke
0.94
2265005000 Gasoline 4-stroke
158.20
2270005000 Diesel
122.72
Total:
281.86

County season-day emissions were calculated by multiplying winter season CO emissions
(generated by the NONROAD2002 model) by the most conservative weekday/weekend day
activity allocation factor for agricultural equipment listed in Table 4.1–1, and dividing the
product by the number of weeks (13) in the CO season (US EPA, 1999), as follows:
Maricopa County CO = Winter season
season-day emissions
CO emissions
(lbs/day)
(tons/season)
= 33.61
= 861.8 lbs/day

× 2000
(lb/ton)

× daily activity allocation factor
for agricultural equipment
expressed as (week/day)
× 0.166667

× 2000

÷ 13
(weeks/season)
÷ 13

Table 4.2–3. Total seasonal and season-day emissions from agricultural equipment in Maricopa County.
Winter
CO season-day
CO emissions
emissions
SCC
Engine type
(tons/season)
(lbs/day)
2260005000 Gasoline 2-stroke
0.11
2.7
2265005000 Gasoline 4-stroke
16.96
434.9
2270005000 Diesel
16.54
424.3
Total:
33.61
861.9

CO nonattainment area season-day emissions were calculated by multiplying county season-day
emissions by the agricultural land-use allocation factor:
CO nonattainment area = Maricopa County CO × Agricultural land-use allocation factor
season-day emissions
season-day emissions
= 861.9 lbs/day
× 44.53%
= 383.8 lbs/day
Table 4.2–4. Season-day emissions from agricultural equipment in CO nonattainment area.
CO emissions
SCC
Engine type
(lbs/day)
2260005000 Gasoline 2-stroke
1.2
2265005000 Gasoline 4-stroke
193.7
2270005000 Diesel
188.9
Total:
383.8

4.3

Airport ground support equipment

Annual emissions from airport ground support equipment in Maricopa County were calculated
using EPA’s NONROAD2002 model, as described in Section 4.1. Annual emissions for the CO
nonattainment area for this category were derived by applying the ratio of the number of FAA
landing and takeoff operations (LTO) in the nonattainment area to Maricopa County-level totals,
as recommended by EIIP guidance (US EPA, 2002). See Section 4.12 for a discussion of aircraft
LTO data.
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Table 4.3–1. Annual emissions from airport ground support equipment.
CO emissions (tons/year)
SCC
Engine type
Maricopa County
Nonattainment area
2260008000
Gasoline 2-stroke
0.00
0.00
2265008000
Gasoline 4-stroke
3,447.92
3,361.72
2270008000
Diesel
23.17
22.59
Totals:
3,471.09
3,384.31

County season-day emissions were calculated by first multiplying Maricopa County annual CO
emissions by 25% to estimate CO season totals, as airport ground support equipment activity is
assumed uniform throughout the year (US EPA, 1999). CO season totals were then multiplied by
the most conservative weekday/weekend day activity allocation factor for airport ground support
equipment (0.1428571) listed in Table 4.1–1, and dividing the product by the number of weeks
(13) in the CO season (US EPA, 1999). CO nonattainment area season-day emissions were
calculated based on LTOs as described above.
Table 4.3–2. CO season-day emissions from airport ground support equipment.
CO emissions (lbs/day)
SCC
Engine type
Maricopa County
Nonattainment area
2260008000
Gasoline 2-stroke
0.0
0.0
2265008000
Gasoline 4-stroke
18,944.6
18,471.0
2270008000
Diesel
127.3
124.1
Totals:
19,071.9
18,595.1

4.4

Commercial equipment

Annual emissions from commercial equipment in Maricopa County were calculated using EPA’s
NONROAD2002 model, as described in Section 4.1. Annual emissions for the CO nonattainment area for this category were derived by applying the ratio of industrial employment in the
nonattainment area to Maricopa County-level totals, as data on the number of wholesale establishments recommended by EIIP guidance (US EPA, 2002) was not available. See Section 1.5.1
for a discussion of the industrial employment data used.
Table 4.4–1. Annual emissions from commercial equipment.
CO emissions (tons/year)
SCC
Engine type
Maricopa County
Nonattainment area
2260006000
Gasoline 2-stroke
557.16
546.52
2265006000
Gasoline 4-stroke
44,729.37
43,875.04
2270006000
Diesel
511.02
501.26
Totals:
45,797.55
44,922.82

County season-day emissions were calculated by multiplying Maricopa County winter season
CO emissions (generated by the NONROAD2002 model) by the most conservative weekday/
weekend day activity allocation factor for commercial equipment (0.1666667) listed in Table
4.1–1, and dividing the product by the number of weeks (13) in the CO season (US EPA, 1999).
CO nonattainment area season-day emissions were calculated based on industrial employment
ratios as described above.

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Table 4.4–2. CO season-day emissions from commercial equipment.
CO emissions (lbs/day)
SCC
Engine type
Maricopa County
Nonattainment area
2260006000
Gasoline 2-stroke
3,070.5
3,011.9
2265006000
Gasoline 4-stroke
237,973.6
233,428.3
2270006000
Diesel
3276.2
3213.6
Totals:
244,320.3
239,653.8

4.5

Construction and mining equipment

Annual emissions from construction and mining equipment in Maricopa County were calculated
using EPA’s NONROAD2002 model as described in Section 4.1. Annual emissions for the CO
nonattainment area for this category were derived by applying the ratio of population in the
nonattainment area to Maricopa County-level totals as a conservative estimate, as the EIIPrecommended allocation factor of total dollar value of construction was unavailable (US EPA,
2002). See Section 1.5.1 for a discussion of the population data used.
Table 4.5–1. Annual emissions from construction and mining equipment.
CO emissions (tons/year)
SCC
Engine type
Maricopa County
Nonattainment area
2260002000
Gasoline 2-stroke
1,170.13
1,147.78
2265002000
Gasoline 4-stroke
9,139.37
8,964.81
2270002000
Diesel
5,275.07
5,174.32
Totals:
15,584.58
15,286.91

County season-day emissions were calculated by multiplying Maricopa County winter season
CO emissions (generated by the NONROAD2002 model) by the most conservative weekday/
weekend day activity allocation factor for construction/mining equipment (0.1666667) listed in
Table 4.1–1, and dividing the product by the number of weeks (13) in the CO season (US EPA,
1999). CO nonattainment area season-day emissions were calculated based on population ratios
as described above.
Table 4.5–2. CO season-day emissions from construction and mining equipment.
CO emissions (lbs/day)
SCC
Engine type
Maricopa County
Nonattainment area
2260002000
Gasoline 2-stroke
5,116.2
5,018.5
2265002000
Gasoline 4-stroke
38,335.4
37,603.2
2270002000
Diesel
27,214.9
26,695.1
Totals:
70,666.5
69,316.8

4.6

Industrial equipment

Annual emissions from industrial equipment in Maricopa County were calculated using EPA’s
NONROAD2002 model, as described in Section 4.1. Annual emissions for the CO
nonattainment area for this category were derived by applying the ratio of industrial employment
in the nonattainment area to Maricopa County-level totals as a conservative estimate, as the
number of employees in manufacturing recommended by EIIP guidance (US EPA, 2002) was
not available. See Section 1.5.1 for a discussion of the industrial employment data used.

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Table 4.6–1. Annual emissions from industrial equipment.
CO emissions (tons/year)
SCC
Engine type
Maricopa County
Nonattainment area
2260003000
Gasoline 2-stroke
7.23
7.09
2265003000
Gasoline 4-stroke
14,638.82
14,359.22
2270003000
Diesel
489.42
480.07
Totals:
15,135.47
14,846.38

County season-day emissions were calculated by multiplying Maricopa County winter-season
CO emissions (generated by the NONROAD2002 model) by the most conservative weekday/
weekend day activity allocation factor for industrial equipment (0.1666667) listed in Table
4.1–1, and dividing the product by the number of weeks (13) in the CO season (US EPA, 1999).
CO nonattainment area season-day emissions were calculated based on industrial employment
ratios as described above.
Table 4.6–2. CO season-day emissions from industrial equipment.
CO emissions (lbs/day)
SCC
Engine type
Maricopa County
Nonattainment area
2260003000
Gasoline 2-stroke
39.9
39.1
2265003000
Gasoline 4-stroke
86,374.9
84,725.1
2270003000
Diesel
3,137.4
3,077.5
Totals:
89,552.2
87,841.8

4.7

Lawn and garden equipment

Annual emissions from lawn and garden equipment in Maricopa County were calculated using
EPA’s NONROAD2002 model, as described in Section 4.1. These results reflect new equipment
population and usage estimates from survey work done in early 2003 for the Arizona Department
of Environmental Quality (discussed further in Section 4.1). Annual emissions for the CO
nonattainment area for this category were derived by applying the ratio of housing units in the
nonattainment area to Maricopa County-level totals, as recommended by EIIP guidance (US
EPA, 2002). See Section 1.5.1 for a discussion of the housing data used.
Table 4.7–1. Annual emissions from lawn and garden equipment.
CO emissions (tons/year)
SCC
Engine type
Maricopa County
Nonattainment area
2260004000
Gasoline 2-stroke
4,677.47
4,592.34
2265004000
Gasoline 4-stroke
72,476.35
71,157.28
2270004000
Diesel
119.31
117.14
Totals:
77,273.13
75,866.76

County season-day emissions were calculated by multiplying Maricopa County winter-season
CO emissions (generated by the NONROAD2002 model) by the most conservative weekday/
weekend day activity allocation factor for lawn and garden equipment (0.1600000 for the
commercial segment, 0.2222222 for residential) listed in Table 4.1–1, and dividing the product
by the number of weeks (13) in the CO season (US EPA, 1999). CO nonattainment area seasonday emissions were calculated based on housing units as described above.

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Table 4.7–2. CO season-day emissions from lawn and garden equipment.
CO emissions (lbs/day)
SCC
Engine type
Maricopa County
Nonattainment area
2260004000
Gasoline 2-stroke
6,369.6
6,253.7
2265004000
Gasoline 4-stroke
104,564.5
102,661.4
2270004000
Diesel
176.2
173.0
Totals:
111,110.3
109,088.1

4.8

Logging equipment

Annual emissions from logging equipment in Maricopa County were calculated using EPA’s
NONROAD2002 model, as described in Section 4.1. Logging equipment includes equipment
such as large chain saws and shredders used by such entities such as city parks departments and
large landscaping companies. Annual emissions for the CO nonattainment area for this category
were derived by applying the ratio of population in the nonattainment area to Maricopa Countylevel totals as a conservative estimate, as the number of employees in logging recommended by
EIIP guidance was not available (US EPA, 2002). See Section 1.5.1 for a discussion of the
population figures used.
Table 4.8–1. Annual emissions from logging equipment.
CO emissions (tons/year)
SCC
Engine type
Maricopa County
Nonattainment area
2260007000
Gasoline 2-stroke
34.30
33.64
2265007000
Gasoline 4-stroke
90.02
88.30
2270007000
Diesel
12.23
12.00
Totals:
136.54
133.93

County season-day emissions were calculated by multiplying Maricopa County winter-season
CO emissions (generated by the NONROAD2002 model) by the most conservative weekday/
weekend day activity allocation factor for logging equipment (0.1666667) listed in Table 4.1–1,
and dividing the product by the number of weeks (13) in the CO season (US EPA, 1999). CO
nonattainment area season-day emissions were calculated based on population as described
above.
Table 4.8–2. CO season-day emissions from logging equipment.
CO emissions (lbs/day)
SCC
Engine type
Maricopa County
Nonattainment area
2260007000
Gasoline 2-stroke
189.0
185.4
2265007000
Gasoline 4-stroke
477.2
468.1
2270007000
Diesel
78.5
77.0
Totals:
744.7
730.5

4.9

Pleasure craft

Annual emissions from pleasure craft equipment in Maricopa County were calculated using
EPA’s NONROAD2002 model, as described in Section 4.1. Annual emissions for the CO
nonattainment area for this category were derived by applying the ratio of water surface area in
the nonattainment area to Maricopa County-level totals, as recommended by EIIP guidance (US
EPA, 2002). See Section 1.5.2 for a discussion of the land use data used.

2002 Carbon Monoxide Periodic Emission Inventory

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Maricopa County, AZ

Table 4.9–1. Annual emissions from pleasure craft equipment.
CO emissions (tons/year)
SCC
Engine type
Maricopa County
Nonattainment area
2260007000
Gasoline 2-stroke
982.10
336.86
2265007000
Gasoline 4-stroke
439.26
150.67
2270007000 Diesel
2.55
0.87
Totals:
1,423.91
488.40

County season-day emissions were calculated by multiplying Maricopa County winter-season
CO emissions (generated by the NONROAD2002 model) by the most conservative weekday/
weekend day activity allocation factor for pleasure craft (0.3500000) listed in Table 4.1–1, and
dividing the product by the number of weeks (13) in the CO season (US EPA, 1999). CO
nonattainment area season-day emissions were calculated based on water surface area as
described above.
Table 4.9–2. CO season-day emissions from pleasure craft equipment.
CO emissions (lbs/day)
SCC
Engine type
Maricopa County
Nonattainment area
2260007000
Gasoline 2-stroke
2,998.3
1,028.4
2265007000
Gasoline 4-stroke
1,264.5
433.7
2270007000
Diesel
9.5
3.3
Totals:
4,272.3
1,465.4

4.10

Railway maintenance equipment

Annual emissions from railway maintenance equipment in Maricopa County were calculated
using EPA’s NONROAD2002 model, as described in Section 4.1. Annual emissions for the CO
nonattainment area for this category were derived by applying the ratio of population in the
nonattainment area to Maricopa County-level totals, as recommended by EIIP guidance (US
EPA, 2002). See Section 1.5.1 for a discussion of the population data used.
Table 4.10–1. Annual emissions from railway maintenance equipment.
CO emissions (tons/year)
SCC
Engine type
Maricopa County
Nonattainment area
2285003015
Gasoline 2-stroke
0.00
0.00
2285004015
Gasoline 4-stroke
43.99
43.15
2285002015
Diesel
17.29
16.96
Totals:
61.28
60.11

County season-day emissions were calculated by multiplying Maricopa County winter season
CO emissions (generated by the NONROAD2002 model) by the most conservative weekday/
weekend day activity allocation factor for railway maintenance equipment (0.1800000) listed in
Table 4.1–1, and dividing the product by the number of weeks (13) in the CO season (US EPA,
1999). CO nonattainment area season-day emissions were calculated based on the population
ratio as described above.

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Table 4.10–2. CO season-day emissions from railway maintenance equipment.
CO emissions (lbs/day)
SCC
Engine type
Maricopa County
Nonattainment area
2285003015
Gasoline 2-stroke
0.0
0.0
2285004015
Gasoline 4-stroke
252.0
247.2
2285002015
Diesel
119.7
117.4
Totals:
371.7
364.6

4.11

Recreational equipment

Annual emissions from recreational equipment in Maricopa County were calculated using EPA’s
NONROAD2002 model, as described in Section 4.1. Annual emissions for the CO nonattainment area for this category were derived by applying the ratio of passive open space, golf
courses and vacant land use in the nonattainment area to Maricopa County-level totals as recommended by EIIP guidance (US EPA, 2002). See Section 1.5.2 for a discussion of the land use
data used.
Table 4.11–1. Annual emissions from recreational equipment.
CO emissions (tons/year)
SCC
Engine type
Maricopa County
Nonattainment area
2260001000
Gasoline 2-stroke
971.01
97.97
2265001000 Gasoline 4-stroke
8,803.03
888.23
2270001000
Diesel
14.16
1.43
Totals:
9,788.20
987.63

County season-day emissions were calculated by multiplying Maricopa County winter-season
CO emissions (generated by the NONROAD2002 model) by the most conservative weekday/
weekend day activity allocation factor for recreational equipment (0.2222222) listed in Table
4.1–1, and dividing the product by the number of weeks (13) in the CO season (US EPA, 1999).
CO nonattainment area season-day emissions were calculated based on land use as described
above.
Table 4.11–2. CO season-day emissions from recreational equipment.
CO emissions (lbs/day)
SCC
Engine type
Maricopa County
Nonattainment area
2260001000
Gasoline 2-stroke
3,327.9
335.8
2265001000
Gasoline 4-stroke
28,706.4
2,896.4
2270001000
Diesel
58.2
5.9
Totals:
32,092.5
3,238.1

4.12

Aircraft

A survey of all 16 airports in Maricopa County was conducted to collect data on the total number
of landing and take-off operations (LTO’s) as well as fleet mix to determine the types of aircraft
used and idle times to calculate annual emissions. Of these airports, three locations (Buckeye
Municipal Airport, Gila Bend Municipal Airport and Wickenburg Municipal Airport) are outside
of the nonattainment area. Data provided by many airports were in the form of the US Federal
Aviation Administration's (FAA) monthly reporting Form 7230-1, which documents the traffic
flow in four major activity categories: air carrier, air taxi, general aviation and military.
2002 Carbon Monoxide Periodic Emission Inventory

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Maricopa County, AZ

Emissions were derived from both computer modeling and National Emissions Inventory (NEI)
default emission factors. For airports that provided complete survey data, the FAA’s latest
airport Emissions and Dispersion Modeling Software (EDMS 4.1) was used to calculate
emissions. Parameters required to apply this model include annual LTO figures, fleet mix of
types of aircraft in each activity category, and average idle-in and idle-out times.
For those airports that provided only partial data, the EDMS model could not be used to calculate
emissions. Instead, NEI default emission factors were used to calculate emissions. Examples of
missing data were detailed fleet mix data or unknown idle times. For airports that did not
respond to the survey, LTO figures and fleet mix were derived from an online database that
provides free detailed aeronautical information on airports at http://www.airnav.com. The
“Airport Operational Statistics” section of this database contains data on average daily aircraft
operations at the airport by aircraft type (air carrier, air taxi, general aviation and military).
These data were multiplied by 365 to derive annual LTO totals and was used to grow LTO’s and
fleet mix. Since the EDMS model requires specific aircraft types to run and the Airport
Operational Statistics only provide general aircraft type information, the NEI default emission
factors shown in Table 4.12–1 were applied to these activity data to calculate emissions
Table 4.12–1. NEI default emission factors, by aircraft type.
Aircraft type
Air taxi
General aviation
Military

Abbreviation
AT
GA
ML

SCC
2275060000
2275050000
2275001000

CO emission
factor (lbs/LTO)
28.130
12.014
28.130

Table 4.12–2 summarizes the data received from each airport, and the approach used (using the
EDMS model or default emission factors from the 1999 NEI) to calculate emissions from each
airport.
The following provides an example of how aircraft emissions were calculated using EDMS for
Skyranch at Carefree, a small, general-aviation only airport with a mix of aircraft 12,500 lbs or
less. Since the EDMS model requires an exact LTO value for each airframe considered in the
model, and since the survey did not require respondents to supply exact LTO counts for each
individual airframe, an averaging method was used. EDMS was run to produce an composite
emission factor for an airport based on the most common type of aircraft using that facility. For
Skyranch, a composite profile was created by selecting within EDMS 12 aircraft types likely to
utilize the airport, based on data provided by the airport survey and follow-up correspondence.
These 12 aircraft types are: Cessna 150, Commanche, Robin R 2160, Socata Tampico, Cessna
172 Skyhawk, Piper PA-28, Robin R 3000, Socata Tobago, Cherokee six, Robin DR 400,
Rockwell Commander, and Spencer S-12 Air Car.
The EDMS model was run with the above 12 aircraft types and for ease of calculation, each
aircraft was allocated 2000 LTO/year. It was then necessary to divide the lbs/LTO result by the
12 representative aircraft used to derive an emission factor for an “average” aircraft LTO.

2002 Carbon Monoxide Periodic Emission Inventory

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Table 4.12–2. 2002 airport activity data and emission calculation methods.
LTO data
Annual
Activity
source1
LTOs
Airport name
category
Arizona Army National Guard
ML
780
reported
Buckeye Municipal Airport3
GA
16,796
reported
Chandler Municipal Airport
AT
914
reported
GA
80,689
reported
ML
10
reported
Falcon Field
AT
1,319
AirNav
GA
125,350
AirNav
ML
5,278
AirNav
Gila Bend Municipal Airport3
GA
522
AirNav
Glendale Municipal Airport
GA
59,352
reported
Luke Air Force Base
ML
61,225
reported
Phoenix Deer Valley Airport
AT
2,495
reported
GA
192,254
reported
ML
37
reported
Phoenix Goodyear Airport
AC
131
reported
AT
270
reported
GA
68,317
reported
ML
569
reported
Phoenix Sky Harbor Int'l. Airport
AC
187,125
reported
AT
57,570
reported
GA
26,204
reported
ML
1,987
reported
Pleasant Valley Airport
GA
19,302
reported
Scottsdale Airport
AT
5,026
reported
GA
92,365
reported
ML
291
reported
Skyranch at Carefree
GA
2,453
reported
Stellar Airpark
GA
22,000
reported
Wickenburg Municipal Airport3
AT
179
AirNav
GA
8,495
AirNav
ML
268
AirNav
Williams Gateway Airport
AC
421
reported
AT
3,104
reported
GA
79,731
reported
ML
5,990
reported
1. “reported” = using 2002 survey results supplied by the airport,
“AirNav” = using available data on average daily LTOs from www.airnav.com.
2. “EDMS” = emission factors were based on EDMS model calculations,
“NEI default” = NEI default emission factors Table 4.12–1 were used.
3. Airport is outside the nonattainment area.

Emission
calculation
method2
NEI default
EDMS
NEI default
NEI default
NEI default
NEI default
NEI default
NEI default
NEI default
NEI default
EDMS
NEI default
NEI default
NEI default
EDMS
NEI default
NEI default
NEI default
EDMS
EDMS
EDMS
EDMS
EDMS
NEI default
NEI default
NEI default
EDMS
NEI default
NEI default
NEI default
NEI default
EDMS
EDMS
EDMS
EDMS

For example, the model run with the 12 aircraft types resulted in total CO emissions of 211.69
tons (assuming each of the 12 aircraft types had 2000 LTOs during the period).
Composite CO emission
factor (lb/LTO)

= Σ modeled CO emissions (tons/yr) × 1 yr ÷ 24,000 LTOs × 2000 lb/ton
= 17.64 lb CO/LTO

This composite emission factor was then multiplied by the actual number of LTOs at the airport
to derive an annual CO emissions total:
2002 Carbon Monoxide Periodic Emission Inventory

68

Maricopa County, AZ

CO emissions (lb/ yr)

= 2,453 LTO/yr × 17.64 lb CO/LTO
= 43,272.88 lb CO/yr

Table 4.12–1 lists the emission factors used. Table 4.12–3 lists the total annual emissions, and
CO season-day emissions, for each airport and aircraft type. For all airports, activity is presumed
to occur evenly over a 7-day week. To develop seasonal allocation factors, Phoenix Sky Harbor
International Airport’s distribution of LTO’s for air carrier activity was used. Seasonal activity
for the CO season (November – January) is thus calculated as (15,245 + 15,865 + 15,091 ÷
187,125 = 25%).
Table 4.12–3. Emission factors, and annual and CO season-day emissions, by airport and aircraft type.
Annual CO Season-day CO
Activity
emissions
emissions
Facility
category1
Lbs/LTO
(tons/yr)
(lbs/day)
Arizona Army Natl. Guard
ML
28.130
10.97
60.3
Chandler Municipal Airport
AT
28.130
12.86
70.6
GA
12.014
484.70
2,663.2
ML
28.130
0.14
0.8
Falcon Field
AT
28.130
18.55
101.9
GA
12.014
752.98
4,137.2
ML
28.130
74.24
407.9
Glendale Municipal Airport
GA
12.014
356.53
1,958.9
Luke Air Force Base
ML
13.827
423.28
2,325.7
Phoenix Deer Valley Airport
AT
28.130
35.09
192.8
GA
12.014
1,154.87
6,345.4
ML
28.130
0.52
2.9
Phoenix Goodyear Airport
AC
7.615
0.50
2.7
AT
28.130
3.80
20.9
GA
12.014
410.38
2,254.8
ML
28.130
8.00
44.0
Phoenix Sky Harbor Int'l. Airport
AC
43.267
4,048.17
22,242.7
AT
14.996
431.66
2,371.8
GA
6.838
89.59
492.3
ML
0.643
0.64
3.5
Pleasant Valley Airport
GA
0.529
5.11
28.1
Scottsdale Airport
AT
28.130
70.69
388.4
GA
12.014
554.84
3,048.6
ML
28.130
4.09
22.5
Skyranch at Carefree
GA
17.641
21.64
118.9
Stellar Airpark
GA
12.014
132.15
726.1
Williams Gateway Airport
AC
6.960
1.47
8.1
AT
14.996
23.27
127.9
GA
18.234
726.91
3994.0
ML
10.288
30.81
169.3
CO nonattainment area totals:
9,888.43
54,332.0
Airports outside the nonattainment area:
Buckeye Municipal Airport
Gila Bend Municipal Airport
Wickenburg Municipal Airport

GA
GA
AT
GA
ML

17.641
12.014
28.130
12.014
28.13

Maricopa County totals:
1. AC = air carrier, GA = general aviation, AT = air taxi, ML = military.

2002 Carbon Monoxide Periodic Emission Inventory

69

148.15
3.14
2.52
51.03
3.77
10,097.03

814.0
17.2
13.8
280.4
20.7
55,478.2

Maricopa County, AZ

4.13

Locomotives

Annual emissions from locomotives were calculated based on diesel fuel usage provided by
Burlington Northern/Santa Fe Railway (BNSF) and Union Pacific Railway (UP). Railway
operations from these companies fall into two categories: Class I haul lines and yard/switching
operations (no Class II or Class III haul lines operated in Maricopa County in 2002). Annual
emissions from Class I haul operations and yard/ switching operations were calculated by
multiplying diesel fuel usage by EPA emission factors for CO (US EPA, 1997).
Emissions from UP = Diesel fuel used (gals) × EPA emission factor (lbs/gal) ÷ 2000 lbs/ton
Class I haul lines
for CO
= 9,204,320 gallons
× 0.059 lbs/gal
÷ 2000 lbs/ton
= 271.53 tons of CO/yr
Table 4.13–1. Fuel use, emission factors, and annual emissions from locomotives in Maricopa County.
Diesel fuel
CO emission
CO emissions
Locomotive type
used (gals)
factor (lbs/gal)
(tons/year)
BNSF Class I haul line
824,339
0.059
24.32
UP Class I haul line
9,204,320
0.059
271.53
BNSF yard/switch operations
824,900
0.084
34.65
UP yard/switch operations
329,960
0.084
13.86
Totals:
11,183,519
344.35

CO nonattainment area emissions were calculated by multiplying Maricopa County emissions by
the percentage of track miles inside the CO nonattainment area, determined by GIS mapping:
CO nonattainment area emissions = County CO emissions
from UP Class I haul lines
= 271.53 tons
= 103.04 tons CO/year

× Percentage of track in
the nonattainment area
× 37.95%

Table 4.13–2. Annual CO nonattainment area emissions from locomotives.
County CO
Track in
CO nonattainment
emissions
nonattainment
area emissions
Locomotive type
(tons/year)
area (%)
(tons/year)
BNSF Class I haul line
24.32
37.95
9.23
UP Class I haul line
271.53
37.95
103.04
BNSF yard/switch operations
34.65
100.00
34.65
UP yard/switch operations
13.86
100.00
13.86
Totals:
344.35
160.78

CO season-day emissions for both the county and the CO nonattainment area were calculated by
dividing annual totals by 365 days per year, as locomotive activity is assumed to be uniform
throughout the year.
CO season-day
= Annual County CO emissions (tons)
emissions from haul lines
= 295.85 tons
= 1,621.1 lbs/day

2002 Carbon Monoxide Periodic Emission Inventory

70

× 2000 lbs/ton

÷

365 days

× 2000 lbs/ton

÷

365 days

Maricopa County, AZ

Table 4.13–3. CO season-day emissions from locomotives.
County CO season-day
SCC
Activity type
emissions (lbs/day)
2285002005 Line haul
1,621.1
2285002010 Yard/switch operations
265.7
Totals:
1,886.8

4.14

CO nonattainment area
season-day emissions (lbs/day)
615.2
265.7
881.0

Summary of all nonroad mobile source emissions

Table 4.30 summarizes the annual and season-day emissions of carbon monoxide from nonroad
mobile sources in Maricopa County and the CO nonattainment area.
Table 4.14–1. Summary of annual and season-day CO emissions from nonroad mobile sources.
Annual emissions (tons/yr)
Season-day emissions (lbs/day)
Maricopa
CO nonattainment
Maricopa
CO nonattainment
Equipment category
County
area
County
area
Agricultural
632.96
281.86
861.9
383.8
Airport ground support equipment
3,471.09
3,384.31
19,071.9
18,595.1
Commercial
45,797.55
44,922.82
244,320.3
239,653.8
Construction & mining
15,584.58
15,286.91
70,666.5
69,316.8
Industrial
15,135.47
14,846.38
89,552.2
87,841.8
Lawn & garden
77,273.13
75,866.76
111,110.3
109,088.1
Logging
136.54
133.93
744.7
730.5
Pleasure craft
1,423.91
488.40
4,272.3
1,465.4
Railway maintenance
61.28
60.11
371.7
364.6
Recreational
9,788.20
987.63
32,092.5
3,238.1
Aircraft
10,097.03
9,888.43
55,478.2
54,332.0
Locomotives
344.35
160.78
1,886.8
881.0
Totals:
179,746.09
166,308.32
630,429.3
585,891.0

4.15

Quality assurance procedures

Established procedures were used to check, and correct when necessary, the off-road mobile
sources emissions estimates. All NONROAD model input and output files, and Excel spreadsheets used to calculate the emissions, were checked by personnel who were not involved in the
development of the modeling inputs/outputs and spreadsheets. In addition, the emissions
estimates were reviewed for reasonableness by external agency staff.

4.16

References

ENVIRON et al., 2003. Maricopa County 2002 Comprehensive Emission Inventory for the Cap
and Trade Oversight Committee, Final Rep. prepared for Arizona Dept. of Environmental
Quality, October 9, 2003.
ERG, 2001. Documentation for the Draft 1999 Base Year Aircraft, Commercial Marine Vessels,
and Locomotive National Emissions Inventory for Criteria and Hazardous Air Pollutants.
Prepared by Eastern Research Group, Morrisville, NC for the US Environmental Protection
Agency, Office of Air Quality Planning and Standards, Research Triangle Park, NC, Oct. 29,
2001. Internet address: http://www.epa.gov/ttn/chief/eidocs/ partllsec4.pdf

2002 Carbon Monoxide Periodic Emission Inventory

71

Maricopa County, AZ

US EPA, 2002. Geographic Allocation of State Level Nonroad Engine Population Data to the
County Level. EPA Office of Transportation and Air Quality, Rep. EPA420-P-02-009, July.
Internet address: http://www.epa.gov/otaq/ models/nonrdmdl/p02009.pdf.
US EPA, 1999. Weekday and Weekend Day Temporal Allocation of Activity in the NONROAD
Model. EPA Office of Transportation and Air Quality, Rep. EPA420-P-99-033, March.
Internet address: http://www.epa.gov/otaq/ models/nonrdmdl/p99033.pdf.
US EPA, 1997. Emission Factors for Locomotives. Office of Mobile Sources. Techn.
Highlights, (Table 9) Rep. EPA420-F-97-051, Dec. 1997. Internet address:
http://www.epa.gov/otaq/regs/nonroad/locomotv/frm/42097051.pdf

2002 Carbon Monoxide Periodic Emission Inventory

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Maricopa County, AZ

5.

Onroad Mobile Sources

5.1

Introduction

The Maricopa Association of Governments (MAG) prepared the onroad mobile source emission
estimates for the 2002 Periodic Carbon Monoxide Emissions Inventory for the Maricopa County
Nonattainment Area and for Maricopa County. Onroad mobile source emission estimates have
been calculated for carbon monoxide (CO) for the 2002 Periodic CO Inventory. These onroad
mobile source estimates are for the CO nonattainment area within Maricopa County and also for
Maricopa County as a whole. Emission estimates were developed for both the carbon monoxide
season and also for 2002 as a whole.
Emission estimates were calculated for the following eight vehicle classes: light duty gas
vehicles (LDGV), light duty gas trucks of gross vehicle weight under 6000 pounds (LDGT1/
LDGT2) or over 6000 pounds (LDGT3/LDGT4), heavy duty gas vehicles (HDGV), light duty
diesel vehicles (LDDV), light duty diesel trucks (LDDT), heavy duty diesel vehicles (HDDV),
and motorcycles (MC). Emission factors for these vehicle classes were calculated using
MOBILE6.2, the latest version in a series of models developed by the US Environmental
Protection Agency (EPA) for the purpose of estimating motor vehicle emission factors. The
resulting emission factors were multiplied by the estimates of vehicle miles of travel (VMT) to
generate emission estimates.
The main reference sources for preparing the onroad mobile source portion of the inventory were
as follows:
• Emission Inventory Requirements for Carbon Monoxide State Implementation Plans,
EPA-450/4-91-011, March 1991, (hereinafter referred to as EPA Guidance),
• Technical Guidance on the Use of MOBILE6 for Emission Inventory Preparation, US
EPA, January 2002,
• User's Guide to MOBILE6.1 and MOBILE6.2 (Mobile Source Emission Factor Model),
EPA420-R-03-010, August 2003, (hereinafter referred to as User's Guide), and
• Procedures for Emission Inventory Preparation Volume IV: Mobile Sources, EPA-450/481-026d (Revised), 1992.

5.2

VMT estimation procedure

MAG prepared the 2002 vehicle miles of travel (VMT) estimates for the carbon monoxide nonattainment area and Maricopa County. The source of data for these estimates is the 2002 Highway Performance Monitoring System (HPMS) data (see Appendix 5.1) submitted to the US
Department of Transportation, Federal Highway Administration (FHWA) by the Arizona
Department of Transportation (ADOT). The ADOT contact person for the HPMS VMT
estimates is Mark Catchpole (602-712-8596).
Each year, ADOT coordinates the collection of HPMS data, including the annual average daily
traffic (AADT) estimates which are utilized to develop HPMS VMT estimates. ADOT provides
the AADT for the state highway system routes including interstates, urban freeways, and principal arterials in Maricopa County. AADTs for other non-local facilities are provided by local
2002 Carbon Monoxide Periodic Emission Inventory

73

Maricopa County, AZ

jurisdictions. ADOT merges the Maricopa County data with information from other Arizona
counties to create the statewide HPMS dataset submitted to FHWA each year.
HPMS contains a number of data elements which describe roadway characteristics and performance for every non-local roadway in Arizona. All non-local roadways have been divided into
sections which are 0.3 to 10 miles in length, in accordance with HPMS criteria. These sections
are called HPMS universe sections. HPMS contains additional data elements which provide
more detailed information on a randomly-selected set of sample sections. The VMT estimates
which ADOT submits to FHWA each year are generated from HPMS universe data for all
interstates, urban freeways, and principal arterials. Sample section data are expanded to estimate
VMT on all other non-local systems.
VMT on local streets in the urbanized portion of Maricopa County is estimated using traffic
counts collected on 50 randomly-selected local streets in June-July of 1994. These counts
resulted in an AADT of 587 for local roads in the urbanized area. To calculate VMT, this
AADT was applied to local road mileage in 1994 obtained from the Maricopa County street
centerline coverage. In 1994, an AADT of 150 was assumed for local roads which are in the
“donut” area. The “donut” area is an HPMS term referring specifically to the area inside the
PM10 nonattainment area, but outside the Phoenix urbanized area boundary. Since 1994, the
AADTs on local streets have been increased annually on the basis of the rate of population
growth in the Maricopa County population; the mileage on local streets is updated annually by
the local jurisdictions in Maricopa County. VMT for the CO nonattainment area, based on the
2002 HPMS data ADOT submitted to FHWA, is summarized by area type and facility type in
Table 5.2–1.
Table 5.2–1. 2002 HPMS VMT by area type and facility type for the CO nonattainment area (annual
average daily traffic).
Area type
Facility type:
1
2
3
4
5
Total
Interstate / Freeway
1,129,051 9,046,583 6,240,489 4,525,653 2,678,544 23,620,320
Principal Arterial / Minor Arterial
1,087,462 8,834,531 9,795,953 6,923,412 2,670,291 29,311,650
Collector
1,046,993 2,727,290 1,694,159
872,616
955,062 7,296,120
Local
195,247 1,991,136 2,564,545 1,689,510
855,772 7,296,210
Totals:
3,458,753 22,599,539 20,295,146 14,011,191 7,159,670 67,524,300
Notes:
1. Area Type = f(DENSITY of a planning district) where:
DENSITY = (Population + 2 × Employment) / Area
For Area Type 1, DENSITY = 20,001+
(Central Business District)
For Area Type 2, DENSITY = 10,001–20,000 (Outlying Central Business District)
For Area Type 3, DENSITY = 5,001–10,000 (Mixed Urban)
For Area Type 4, DENSITY = 1,001–5,000
(Suburban)
For Area Type 5, DENSITY = 0–1,000
(Rural)
2. Total VMT by facility type is extracted from the appropriate HPMS templates, with the urbanized area
VMT reduced by 1 percent and the donut area VMT reduced by 28 percent.
3. VMT is split up into Area Types using data from MAG 2002 EMME/2 travel demand modeling results.
4. In some cases, the total VMT estimates may differ slightly from the sum of the component VMT estimates
due to rounding. This difference will not exceed one vehicle mile of travel.

2002 Carbon Monoxide Periodic Emission Inventory

74

Maricopa County, AZ

The 2002 HPMS System Length and Daily Vehicle Travel for individual urbanized areas (in
Appendix 5.1) was submitted to FHWA by ADOT in October 2003. This table reported a 2002
average daily VMT (AADT) for the Phoenix urbanized area (#33) of 63.338 million. In comparison, the 2002 urbanized area VMT for the CO nonattainment area used in the periodic emissions inventory is 62.705 million. The one percent difference between these totals is attributable
to small sections of the Phoenix urbanized area (i.e. Apache Junction) which are not located in
the CO nonattainment area and Maricopa County. The HPMS System Length and Daily Vehicle
Travel, donut area data for individual NAAQS nonattainment areas, (in Appendix 5.1), reported
a 2002 VMT for the “donut” area (#33) of 6.694 million. The factors (i.e. 99 percent for the
urbanized area and 72 percent for the donut area) used to determine the allocation of HPMS
VMT to the CO nonattainment area were derived from the report, “Maricopa Association of
Governments Highway Performance Monitoring System Update Study”, January 1995. These
factors were also used to derive VMT for the CO tracking area in Chapter Three of the “MAG
1999 Serious Area Carbon Monoxide Plan for the Maricopa County Nonattainment Area”, June
1999. The total 2002 daily VMT for the urbanized and “donut” areas in the CO nonattainment
area is 67.524 million, as shown in Table 5.2–1. It is important to note that the 2002 HPMS
daily VMT for the CO nonattainment area is within one percent of the 2002 VMT estimated by
the MAG EMME/2 travel demand models for the same domain (after conversion of EMME/2
estimates from average weekday traffic to annual average daily traffic).
The distribution of VMT by facility type for the CO nonattainment area in Table 5.2–1 was
derived from the 2002 HPMS data, while the distribution by area type was derived from a MAG
EMME/2 travel demand model run for 2002. The output of this traffic assignment was evaluated
using GIS to obtain VMT by area type and facility type for the Phoenix urbanized and “donut”
areas. The area type distributions from the EMME/2 assignment were applied to the 2002
HPMS VMT estimates by facility type for the urbanized and “donut” areas to create Table 5.2–1.
VMT estimates for all of Maricopa County were also developed by ADOT. The VMT division
by area type for all of Maricopa County were developed by applying all additional VMT for each
facility type to the Area Type 5 (rural) category, since all VMT outside of the CO nonattainment
area but inside Maricopa County is expected to be in a rural setting. The total VMT estimated
for Maricopa County is 73.579 million miles per day for an annual average day. The VMT
estimates for Maricopa County are shown in Table 5.2–2.
Table 5.2–2.
traffic)

2002 HPMS VMT by area type and facility type for Maricopa County (annual average daily

Area Type
Facility type:
1
2
3
4
5
Total
Interstate / Freeway
1,129,051 9,046,583 6,240,489 4,525,653 5,662,224 26,604,000
Principal Arterial / Minor Arterial
1,087,462 8,834,531 9,795,953 6,923,412 3,738,642 30,380,000
Collector
1,046,993 2,727,290 1,694,159
872,616 2,390,942 8,732,000
Local
195,247 1,991,136 2,564,545 1,689,510 1,422,562 7,863,000
Totals:
3,458,753 22,599,540 20,295,146 14,011,191 13,214,370 73,579,000
Notes:
1. For the definition of “Area Type”, see Table 5.2–1, Note 1.
2. VMT is split up into Area Types using data from MAG 2002 EMME/2 travel demand modeling results. All
VMT outside of the HPMS urbanized and donut areas were applied to Area Type 5.
3. In some cases, the total VMT estimates may differ slightly from the sum of the component VMT estimates
due to rounding. This difference will not exceed one vehicle mile of travel.
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Although HPMS reports vehicle mix data for urban and rural areas of Arizona, there are
insufficient classification stations in the Phoenix urbanized area to justify use of this information
in calculating VMT by vehicle class. In addition, the HPMS vehicle class data do not
discriminate between gas and diesel vehicles. Therefore, MOBILE6.2 model defaults,
representing the fraction of total VMT for each vehicle class, were applied to VMT estimates for
each facility type and area type.

5.3

Speed estimation procedure

MAG prepared the average daily speeds for the onroad mobile sources portion of the 2002
periodic CO emissions inventory. The average daily speeds were developed from several
sources representing the latest planning assumptions for 2002.
For the Interstate/Freeway category and for the Principal/Minor Arterial category, the speeds
were developed using data in the February 11, 2004 draft report 2002-2003 MAG Regional
Travel Time & Travel Speed Study. This report contained data for the functional classifications
“HOV”, “Freeway”, “Expressway”, “6 Leg Arterial”, and “Major Arterial”. Speeds for the first
three categories were combined through a weighted average to develop the average speed for the
Interstate/Freeway category used in the Periodic Inventory. Similarly, the two arterial categories
contained in the speed study were combined through a weighted averaging to obtain a Principal
Arterial/Minor Arterial category speed. In both of these categories, speeds were unique by area
type.
The third facility type included in the periodic inventory is collectors. To develop speed estimates for this facility type, speeds were extracted from the latest 2002 travel demand model run
created using the EMME/2 software. In the EMME/2 runs performed by MAG, some traffic
links that are classified as “locals” would actually be classified as “collectors” by HPMS. The
EMME/2 runs also contain artificial links that are categorized as locals. Since the HPMS
collector category includes some EMME/2 collector links and some EMME/2 locals, the
EMME/2 speeds for locals and collectors were averaged and the result was used for the HPMS
category of collectors. Like the speeds for the Interstate/Freeway and Principal/Minor Arterials
categories, the speeds for Collectors were calculated separately for each of the five area types.
The fourth of the HPMS facility types is local roadways. The MOBILE6.2 model assumes a set
speed of 12.9 miles per hour for local roadways. This speed was incorporated into the current
analysis for all local roadways, regardless of area type.
Table 5.3–1.

Average daily speeds (mph) for the 2002 periodic emissions inventory.
Area Type *
Facility type:
1
2
3
4
Interstate / Freeway
59.7
60.3
63.2
64.8
Principal Arterial / Minor Arterial
30.3
34.4
36.1
39.0
Collector
18.2
19.1
24.4
24.7
Local
12.9
12.9
12.9
12.9
* For the definition of “Area Type”, see Table 5.2–1, Note 1.

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5
64.2
42.6
28.2
12.9

Maricopa County, AZ

5.4

Monthly VMT factors

In the development of annual emissions totals for this inventory, emission factor estimates were
estimated independently for each month, with month-specific meteorological and fuel data.
Since average daily VMT varies by month, and the number of days in each month varies, these
monthly average emission factors were weighted to more appropriately represent an annual
average emission factor. Similarly, the conversion of annual average day traffic to the three
months of the peak CO season utilized the monthly VMT factors listed below.
Average daily VMT estimate factors were developed from the 1998 MAG Regional Congestion
Study and the monthly factors are as follows:
Table 5.4–1.
Month
January
February
March
April
May
June

Average daily VMT adjustment factors by month.
Avg daily VMT
Avg daily VMT
estimate factor
Month
estimate factor
0.98
July
0.94
1.03
August
0.96
1.03
September
0.99
1.03
October
1.02
0.99
November
1.02
0.98
December
1.04

These factors indicate, as an example, that an average day in February has three percent more
traffic than an average month while an average day in June has two percent less traffic than
average. Separately, the different number of days in a month will effect the weighting of
monthly emission factors to an annual average. For instance, if each month had the same
number of days, each monthly emission factor would be equally weighted by 1/12 (0.0833).
Since each month does not have the same number of days, the monthly emission factors are
weighted accordingly, with January being weighted 31/365 (0.0849), February being weighted
28/365 (0.0767), etc. Combining the two sets of adjustments, the February emission factors
would be weighted by 1.03 × 0.0767 in the development of the annual emission factors.
These weightings are applied by the FORTRAN program “NEIProgram”, which was created by
MAG. NEIProgram reads in the individual MOBILE6.2 output files for all twelve months and
for the I/M versus non-I/M scenarios. NEIProgram weighs those 24 sets of MOBILE6.2 output
files to a single set of annual average emission factors. The complete source code for
NEIProgram may be found in Appendix 5.6.
The same monthly factors were used to convert the annual average daily traffic estimates from
the HPMS system to reflect an average day during the peak CO season. The peak CO season
reflects the three consecutive months when peak CO concentrations occur. For consistency with
the 1999 carbon monoxide inventory, the three consecutive months selected were November
2002 through January 2003, in accordance with EPA guidance. Averaging the monthly factors
for November through January results in a factor of 1.01.

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Table 5.4–2. Average daily VMT during 2002 carbon monoxide season for the CO nonattainment area
(November 2002–January 2003).
Area Type
Facility type:
1
2
3
4
5
Total
Interstate / Freeway
1,140,342 9,137,049 6,302,894 4,570,910 2,705,329 23,856,523
Principal Arterial / Minor Arterial
1,098,337 8,922,876 9,893,913 6,992,646 2,696,994 29,604,765
Collector
1,057,463 2,754,563 1,711,101
881,342
964,613 7,369,081
Local
197,199 2,011,047 2,590,190 1,706,405
864,330 7,369,172
Totals:
3,493,341 22,825,535 20,498,098 14,151,303 7,231,266 68,199,541
Notes:
1. For the definition of “Area Type”, see Table 5.2–1, Note 1.
2. In some cases, the total VMT estimates may differ slightly from the sum of the component VMT estimates
due to rounding. This difference will not exceed one vehicle mile of travel.

Table 5.4–3. Average daily VMT during 2002 carbon monoxide season for Maricopa County (November
2002–January 2003).
Area Type
Facility type:
1
2
3
4
5
Total
Interstate / Freeway
1,140,342 9,137,049 6,302,894 4,570,910 5,718,846 26,870,041
Principal Arterial / Minor Arterial
1,098,337 8,922,876 9,893,913 6,992,646 3,776,028 30,683,800
Collector
1,057,463 2,754,563 1,711,101
881,342 2,414,851 8,819,320
Local
197,199 2,011,047 2,590,190 1,706,405 1,436,788 7,941,629
Totals:
3,493,341 22,825,535 20,498,098 14,151,303 13,346,513 74,314,790
Notes:
1. For the definition of “Area Type”, see Table 5.2–1, Note 1.
2. In some cases, the total VMT estimates may differ slightly from the sum of the component VMT estimates
due to rounding. This difference will not exceed one vehicle mile of travel.

5.5

Emission factor estimation procedure

5.5.1

Emission factor model

CO vehicle exhaust emission factors were calculated using MOBILE6.2, the latest version in a
series of models developed by the US EPA for the purpose of estimating motor vehicle emission
factors. The resulting emission factors were combined with vehicle miles of travel (VMT)
estimates to produce emission estimates for carbon monoxide. The MOBILE6.2 runs were
executed by the Maricopa Association of Governments. The contact person for the MOBILE6.2
emission estimates is Roger Roy (602-254-6300).
For the CO season analysis, two MOBILE6.2 runs were executed for a typical day (24-hour
period) during the three-month period of November through January. For the annual emissions
estimates, two MOBILE6.2 runs were executed for each month of the year using month specific
fuel and temperature data, reflecting vehicles registered locally (subject to the I/M program) and
those not registered locally (not participating in the I/M program).
The emission factors estimated with these runs were combined to reflect the actual proportions
of vehicles subject to the specified levels of inspection. The term “I/M vehicles” denotes
vehicles which are required to undergo an emission test and/or inspection under the Arizona
Vehicle Inspection/Maintenance Program. It is important to note that participation in the I/M
program is required for all vehicles registered in the nonattainment area, with the exception of
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certain model year and vehicle classes. However, it is assumed that of the vehicles which are of
an age and type subject to an I/M program, only 91.7 percent of the vehicles operating within the
nonattainment area participate in the I/M program. The remaining 8.3 percent do not participate
in the program. These percentages reflect the control measures “Tougher Registration Enforcement” and “Expansion of Area A Boundaries”, described in the Revised MAG 1999 Serious
Area Carbon Monoxide Plan for the Maricopa County Nonattainment Area, MAG, March 2001.
In the absence of any additional data, this percentage split is assumed to apply directly to VMT
as well. Refer to Appendix 5.2 for portions of the actual input and output files and a spreadsheet
showing the emission factor calculations.

5.5.2

Development of model inputs

The inputs to MOBILE6.2 are grouped into three categories: Header inputs, run inputs, and
scenario inputs. The input values used in the MOBILE6.2 runs are specified and explained
below This next section looks like it maybe should be an appendix section. Humidity was not
used as an input to these runs. After reviewing the MOBILE6.2 guidance on the use of local
humidity data (see page 7 of http://www.epa.gov/otaq/models/mobile6/m6techgd.pdf) , it does
not appear that inputting specific humidity values would be appropriate for the development of
an annual average emissions inventory of this type.
Header Section
1.

MOBILE6 INPUT FILE: indicates that the MOBILE6.2 input file is a regular
command file rather than a batch file.

2.

POLLUTANTS: CO indicates that the only pollutant for which output is desired is
carbon monoxide for this analysis. For the annual CO emissions estimate, the monthly
MOBILE6.2 runs performed did not include this flag because other emission factor
estimates in addition to CO were desired.

Run Data Section
1.

NO REFUELING: indicates that refueling emissions are excluded from the MOBILE6.2
outputs. This command is included for completeness, but does not affect carbon
monoxide outputs.

2.

I/M PROGRAM: 1 1977 2050 1 T/O LOADED IDLE indicates the program start and
end dates, frequency of testing, and test type. There are five components of the I/M
program modeled; a loaded idle test for heavy duty gasoline vehicles (shown in the
example in Appendix 5.2), a transient idle test (I/M240 modeled as a surrogate for the
I/M147 test) for light duty cars and trucks through model year 1995, a loaded idle test for
light duty cars and trucks of model years 1967 to 1980, an on-board diagnostic (OBD)
exhaust test for model year 1996 and newer vehicles, and an OBD evaporative test for the
same vehicles. The remaining four occurrences of this command are as follows:

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I/M PROGRAM: 2 1977 2050 2 T/O IM240 - relating to the transient idle I/M240
program modeled as a surrogate for the I/M147 program.
I/M PROGRAM: 3 1977 2050 1 T/O LOADED IDLE - relating to the loaded idle
program for model year 1967-1980 light duty cars and trucks.
I/M PROGRAM: 4 2001 2050 2 T/O OBD I/M - relating to the exhaust portion of the
OBD test.
I/M PROGRAM: 5 2001 2050 2 T/O EVAP OBD & GC - relating to the evaporative
and gas cap portion of the OBD test.
3.

I/M MODEL YEARS: 1 1967 2050 indicates the first and last model years affected by
the given component of the I/M program. The inputs shown above indicate that model
years 1967 and newer are tested by component 1 of the I/M program. The remaining four
occurrences of this command are as follows:
I/M MODEL YEARS: 2 1981 1995 - relating to the transient idle I/M240 program
modeled as a surrogate for the I/M147 program.
I/M MODEL YEARS: 3 1967 1980 - relating to the loaded idle program for model year
1967-1980 light duty cars and trucks.
I/M MODEL YEARS: 4 1996 2050 - relating to the exhaust portion of the OBD test.
I/M MODEL YEARS: 5 1996 2050 - relating to the evaporative and gas cap portion of
the OBD test.

4.

I/M VEHICLES: 1 11111 22222222 2 indicates that for the first component of the
I/M program (1), the five vehicle categories LDGV, LDGT1, LDGT2, LDGT3, and
LDGT4 are not subject to this portion of the I/M program (indicated by “1”) while
HDGV2B, HDGV3, HDGV4, HDGV5, HDGV6, HDGV7, HDGV8A, HDGV8B, and
gasoline buses are covered (indicated by “2”). The remaining four occurrences of this
command are as follows:
I/M VEHICLES: 2 22222 11111111 1 indicates that the opposite vehicle classes are
subject to the transient idle I/M240 program modeled as a surrogate for the I/M147
program. This selection of vehicle classes is also applied to the remaining three portions
of the I/M program.

5.

I/M STRINGENCY: 1 28.0 indicates that the initial test failure rate for pre-1981
LDGVs and pre-1984 LDGTs is 28.0 percent. This stringency rate is also applied to the
remaining portions of the I/M program.

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6.

I/M COMPLIANCE: 1 97.0 indicates that the fraction of the total vehicle fleet subject
to the I/M program that passes the I/M test or receives a waiver is 97.0 percent. This
compliance rate is also applied to the remaining portion of the I/M program.

7.

I/M WAIVER RATES: 1 1.3 1.0 indicates that the fraction of vehicles that fail the I/M
program is 1.3 for pre-1981 model years and 1.0 percent for 1981 and later model years.
These waiver rates are also applied to the remaining portion of the I/M program.

8.

I/M GRACE PERIOD: 1 5 indicates that vehicles less than 5 years old are exempted
from the I/M program. This exemption is identical for all portions of the I/M program.

9.

I/M CUTPOINTS: 2 CUTcmp03.d indicates that for the CO peak season analysis,
MOBILE6.2 reads the external data file “CUTcmp03.d” for the I/M cutpoint values for
HC, CO, and NOx. There are 25 values for each vehicle class and pollutant, for the most
recent 25 model years, starting with the youngest vehicle. This data is only input for the
I/M240 program. For the monthly MOBILE6.2 runs performed to develop the annual
CO emissions estimates, the file CUTcmp02.d was used for the January through
September 2002 analyses and CUTcmp03.d was used for October through December.

10.

ANTI-TAMP PROGRAM: 87 75 80 22222 22222222 2 11 097. 22111222 indicates
the nature of the anti-tampering program. Specifically, this portion of the anti-tampering
program began in 1987 and covers model year vehicles 1975 to 1980. Vehicle classes
subject to the inspection (indicated by a “2”) include LDGV, LDGT1, LDGT2, LDGT3,
LDGT4, HDGV2B, HDGV3, HDGV4, HDGV5, HDGV6, HDGV7, HDGV8A,
HDGV8B, and gasoline powered buses. The test is performed annually. The test has a
97 percent compliance rate. The parameters tested include air pump disablement,
catalyst removal, evaporative system disablement, PCV system disablement, and missing
gas cap. The parameters not tested are fuel inlet restrictor disablement, tailpipe lead
deposit test, and EGR disablement. A second data line indicates that the same test is also
performed on model year 1981 to 1995 vehicles, but with the LDGV, LDGT1, LDGT2,
LDGT3, and LDGT4 classes omitted because those vehicles are subject to the transient
I/M or OBD test.

11.

REG DIST: 02reg03.d indicates that for the CO peak season analysis, vehicle registration distributions by age for the 16 composite vehicle types are read by MOBILE6.2
from an external data file, called 02reg03.d. The raw data upon which the registration
distributions and diesel fractions are based may be found in Appendix 5.3. The file
02reg02.d was used for the months January through September, 2002. The file 02reg03.d
was used for the remaining months of October 2002 through December 2002 because
those analyses are closer to a January 2003 scenario than a July 2002 scenario.

12.

DIESEL FRACTIONS: indicates the user-supplied diesel sales fractions. This input is
followed by 350 fractional values representing the fraction of the 14 vehicle classes
internally examined by MOBILE6.2 and 25 most recent model years that are diesel
vehicles. As an example, the first value, 0.0050, indicates that for the most recent model
year of light duty vehicles, 0.5 percent of the vehicles sold are diesel.

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Scenario Section
1.

SCENARIO RECORD: Allows the user to enter a name to identify the scenario being
run.

2.

CALENDAR YEAR: 2003 was input because the applicable three-month period for the
CO season inventory is November and December of 2002 and January 2003. To be
consistent with the User's Guide, the calendar year 2003 was chosen to model conditions
representative of the applicable period. For the annual emission estimates, the calendar
year 2002 was chosen for the months January through September while for the months of
October through December, the calendar year 2003 was chosen because a January 2003
scenario more closely matches those months than a January 2002 scenario.

3.

EVALUATION MONTH: 1 indicates that the month to be modeled for the peak CO
season inventory is January. For the annual emissions estimates, the months January
through March and October through December were run with this setting while the
remaining months were processed with the evaluation month set to July. January and
July are the only settings allowed for the evaluation month.

4.

ALTITUDE:1 indicates the geographic area modeled was low altitude.

5.

MIN/MAX TEMPERATURE: 45.0 73. provides the model with the daily minimum
and maximum temperatures for the peak CO season day modeled. The temperatures used
are consistent with those modeled for the previous carbon monoxide periodic inventories.
For the monthly analyses used to estimate annual emissions, temperatures were derived
from the appropriate Sky Harbor Airport Local Climatological Data (LCD) reports. The
raw meteorological data may be found in Appendix 5.4.

6.

AVERAGE SPEED: various speeds analyzed indicates to MOBILE6.2 the average
speed to be modeled for each facility type and area type combination. All facility and
area type combinations with unique speeds will be modeled in this manner.

7.

VMT BY FACILITY: allfwy.def indicates to MOBILE6.2 that the external file
allfwy.def is to be referenced for the ratio of VMT by hour by facility type. The file
allfwy indicates that all VMT is occurring on the MOBILE6.2 facility type freeways for
use in developing the emission factors for the periodic inventory functional
classifications Interstates/Freeways/Expressways. Similarly, the external file allart.def is
called when estimating the emission factors for the arterials or collectors, and allloc.def is
called when estimating the emission factors for the periodic inventory category locals.

8.

FUEL RVP: 8.5 Indicates that the average Reid Vapor Pressure of the gasoline sold is
8.5 pounds per square inch for the peak CO season day modeled. This estimate is based
upon raw gasoline data provided by the Arizona Department of Weights and Measures.
Specifically, this value represents the average RVP of 138 samples collected during
November and December of 2002. For the annual emissions estimates, monthly RVP
estimates were derived from the Arizona Department of Weights and Measures data table
for use in the monthly MOBILE6.2 analyses incorporated into this analysis. Monthly

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fuel qualities, including RVP, sulfur content, and ethanol content, are summarized in
Appendix 5.7.
9.

FUEL PROGRAM: 4 Indicates that the model is to be run with user-supplied gasoline
sulfur levels. The following four lines include 32 numbers, the first 16 listing the
average gasoline sulfur value in parts per million for the years 2000 through 2015 and the
second 16 indicate the maximum gasoline sulfur content vehicles of model year 2000
through 2015 will be exposed. For the purposes of this analysis, the gasoline data from
the time period of November and December 2002 was examined and the average sampled
sulfur values during that time period were entered for all time periods. Similarly, the
gasoline data for all of 2002 was examined and the maximum sulfur value during that
time period was entered for each model year of 2000 through 2015. Those values were
45.6 for average sulfur content and 338.0 ppm for a maximum sulfur content. For the
monthly MOBILE6.2 analyses incorporated into this analysis, the average monthly sulfur
content from the Arizona Department of Weights and Measures data table were used for
the average sulfur value while the 338.0 ppm estimate was used for each month as the
maximum sulfur content.

10.

OXYGENATED FUELS: 0.000 1.000 0.000 0.031 1 Indicates that the 0 percent of the
gasoline sold during the CO season modeled used MTBE as an oxygenate and 100
percent of the gasoline used ethanol as an oxygenate. The average MTBE content was
0.0 percent by weight and the average ethanol content was 3.1 percent by weight. The
number “1” indicates that no RVP waiver has been granted to allow for the “splash”
blending of ethanol oxygenates. For the monthly MOBILE6.2 analyses incorporated into
this analysis, the average monthly oxygenate content from the Arizona Department of
Weights and Measures data table were used, with the exception of January through
March 2003, a time period during which no oxygenate data were available. For those
months, an average of the oxygenate data from the months November and December
were used.

5.5.3

Model outputs

MOBILE6.2 was executed with the inputs described above to obtain composite emission factors
in grams per mile (g/mi) for exhaust CO. These values were obtained for the eight vehicle
classes described in section 5.1 for the various speeds as described in item six of the Scenario
Section, described on the preceding page. The emission factors generated for 2002 are presented
in the following section. Representative output runs are contained in Appendix 5.2. These
values were subsequently used in developing emission estimates.

5.5.4

Summary of emission factors

Refer to Appendix 5.2 for the emission factors developed for CO for each facility and area type.

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5.5.5

Emission estimates

MOBILE6.2 was used to generate CO emission factors for vehicle class, facility, and area type.
Daily VMT for the CO season (Table 5.4–2 and 5.4–3) or for a monthly average day (Table 5.2–
1 and 5.2–2) was then multiplied by the VMT mix by vehicle class and the appropriate CO
emission factor (Appendix 5.2) to estimate CO emissions on a kilogram per day (kg/day) basis.
VMT mix refers to the fraction of total onroad vehicle miles of travel from a particular vehicle
type. For example, since the EPA MOBILE6.2 model estimates that 42.2 percent of onroad
VMT was from light duty gasoline vehicles, the VMT Mix value for LDGVs is 0.422. An
example calculation is given below, reflecting light duty gasoline vehicles on interstates, freeways, and expressways in area type 1 (see Table 5-4(a) at this time, 5-4(a) can not be changed to
5.4–4 and on:
CO emissions = DMVT
(kg/day)

× VMT mix × CO emission factor
(g/mi)

= 1,140,342 × 0.422
= 5,991 kg CO/day

× 12.446

÷ unit conversion factor
(g/kg)
÷ 1,000

CO emissions = CO emissions ÷ unit conversion factor
(lb/day)
(kg/day)
(kg/lb)
= 5,991 kg
÷ 0.4536
= 13,208 lb CO/day

Tables 5.5–1 though 5.5–4 show daily VMT data, associated speed estimates, MOBILE6.2
emission factors, and the calculated CO emissions for each vehicle class, facility type, and area
type for the CO season runs and the annual average runs for the CO nonattainment area and
Maricopa County, respectively.

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Table 5.5–1. Daily CO emissions in the CO nonattainment area, by vehicle class, facility type and area type
(peak CO season day).
Vehicle
Area Speed
Emission
DVMT
Emissions
Emissions
Facility type
class
type (mph) factor (g/mi)
(miles)
(lb/day)
(kg/day)
1
59.7
12.446
1,140,342
13,208.0
5,991.2
INTERSTATE,
LDGV
2
60.3
12.496
9,137,049
106,262.3
48,200.6
FREEWAY,
with VMT
3
63.2
12.526
6,302,894
73,477.5
33,329.4
and
mix of
4
64.8
12.526
4,570,910
53,286.5
24,170.7
EXPRESSWAY
42.2%
5
64.2
12.526
2,705,329
31,538.0
14,305.7
1
59.7
16.382
1,140,342
11,804.6
5,354.6
LDGT1
2
60.3
16.442
9,137,049
94,931.3
43,060.8
with VMT
3
63.2
16.483
6,302,894
65,647.8
29,777.9
mix of
4
64.8
16.483
4,570,910
47,608.3
21,595.1
28.7%
5
64.2
16.483
2,705,329
28,177.4
12,781.3
1
59.7
17.857
1,140,342
5,998.2
2,720.8
LDGT2
2
60.3
17.928
9,137,049
48,251.3
21,886.8
with VMT
3
63.2
17.969
6,302,894
33,360.4
15,132.3
mix of
4
64.8
17.969
4,570,910
24,193.2
10,974.0
13.4%
5
64.2
17.969
2,705,329
14,319.0
6,495.1
1
59.7
10.036
1,140,342
898.3
407.5
HDGV
2
60.3
10.289
9,137,049
7,378.8
3,347.0
with VMT
3
63.2
10.450
6,302,894
5,170.0
2,345.1
mix of
4
64.8
10.450
4,570,910
3,749.3
1,700.7
3.6%
5
64.2
10.450
2,705,329
2,219.1
1,006.6
1
59.7
1.258
1,140,342
7.0
3.2
LDDV
2
60.3
1.268
9,137,049
56.2
25.5
with VMT
3
63.2
1.275
6,302,894
39.0
17.7
mix of
4
64.8
1.275
4,570,910
28.3
12.8
0.2%
5
64.2
1.275
2,705,329
16.7
7.6
1
59.7
0.655
1,140,342
37.7
17.1
LDDT
2
60.3
0.661
9,137,049
304.9
138.3
with VMT
3
63.2
0.666
6,302,894
211.9
96.1
mix of
4
64.8
0.666
4,570,910
153.7
69.7
2.3%
5
64.2
0.666
2,705,329
91.0
41.3
1
59.7
2.287
1,140,342
528.4
239.7
HDDV
2
60.3
2.324
9,137,049
4,302.6
1,951.6
with VMT
3
63.2
2.349
6,302,894
2,999.9
1,360.8
mix of
4
64.8
2.349
4,570,910
2,175.6
986.8
9.2%
5
64.2
2.349
2,705,329
1,287.6
584.1
1
59.7
16.110
1,140,342
202.5
91.9
MC
2
60.3
16.790
9,137,049
1,691.2
767.1
with VMT
3
63.2
17.230
6,302,894
1,197.2
543.0
mix of
4
64.8
17.230
4,570,910
868.2
393.8
0.5%
5
64.2
17.230
2,705,329
513.9
233.1

2002 Carbon Monoxide Periodic Emission Inventory

85

Maricopa County, AZ

Table 5.5–1. Daily CO emissions in the CO nonattainment area, by vehicle class, facility type and area type
(peak CO season day) (continued).
Vehicle
Area Speed
Emission
DVMT
Emissions
Emissions
Facility type
class
type (mph) factor (g/mi)
(miles)
(lb/day)
(kg/day)
1
30.3
9.753
1,098,337
9,969.5
4,522.1
PRINCIPAL
LDGV
2
34.4
9.832
8,922,876
81,642.3
37,032.9
ARTERIALS
with VMT
3
36.1
9.933
9,893,913
91,463.1
41,487.7
and
mix of
4
39.0
10.157
6,992,646
66,101.4
29,983.6
MINOR
42.2%
5
42.6
10.451
2,696,994
26,230.9
11,898.3
ARTERIALS
1
30.3
13.315
1,098,337
9,240.9
4,191.7
LDGT1
2
34.4
13.423
8,922,876
75,683.6
34,330.1
with VMT
3
36.1
13.544
9,893,913
84,675.4
38,408.7
mix of
4
39.0
13.816
6,992,646
61,049.4
27,692.0
28.7%
5
42.6
14.151
2,696,994
24,115.6
10,938.8
1
30.3
14.437
1,098,337
4,670.8
2,118.7
LDGT2
2
34.4
14.545
8,922,876
38,228.1
17,340.3
with VMT
3
36.1
14.685
9,893,913
42,798.7
19,413.5
mix of
4
39.0
14.989
6,992,646
30,873.3
14,004.1
13.4%
5
42.6
15.373
2,696,994
12,212.7
5,539.7
1
30.3
8.457
1,098,337
729.1
330.7
HDGV
2
34.4
7.578
8,922,876
5,307.4
2,407.4
with VMT
3
36.1
7.335
9,893,913
5,696.0
2,583.7
mix of
4
39.0
7.011
6,992,646
3,848.2
1,745.6
3.6%
5
42.6
6.829
2,696,994
1,445.6
655.7
1
30.3
1.311
1,098,337
7.0
3.2
LDDV
2
34.4
1.231
8,922,876
53.3
24.2
with VMT
3
36.1
1.207
9,893,913
57.9
26.3
mix of
4
39.0
1.173
6,992,646
39.8
18.0
0.2%
5
42.6
1.147
2,696,994
15.0
6.8
1
30.3
0.688
1,098,337
38.2
17.3
LDDT
2
34.4
0.638
8,922,876
287.4
130.4
with VMT
3
36.1
0.622
9,893,913
310.7
140.9
mix of
4
39.0
0.601
6,992,646
212.2
96.2
2.3%
5
42.6
0.584
2,696,994
79.5
36.1
1
30.3
2.472
1,098,337
550.1
249.5
HDDV
2
34.4
2.195
8,922,876
3,968.5
1,800.1
with VMT
3
36.1
2.110
9,893,913
4,230.0
1,918.7
mix of
4
39.0
1.993
6,992,646
2,823.8
1,280.9
9.2%
5
42.6
1.901
2,696,994
1,038.8
471.2
1
30.3
10.210
1,098,337
123.6
56.1
MC
2
34.4
9.250
8,922,876
909.9
412.7
with VMT
3
36.1
8.930
9,893,913
974.0
441.8
mix of
4
39.0
8.460
6,992,646
652.2
295.8
0.5%
5
42.6
8.040
2,696,994
239.0
108.4

2002 Carbon Monoxide Periodic Emission Inventory

86

Maricopa County, AZ

Table 5.5–1. Daily CO emissions in the CO nonattainment area, by vehicle class, facility type and area type
(peak CO season day) (continued).
Vehicle
Area Speed
Emission
DVMT
Emissions
Emissions
Facility type
class
type (mph) factor (g/mi)
(miles)
(lb/day)
(kg/day)
1
18.2
10.314
1,057,463
10,150.3
4,604.2
COLLECTOR
LDGV
2
19.1
10.220
2,754,563
26,198.8
11,883.8
with VMT
3
24.4
9.873
1,711,101
15,722.5
7,131.7
mix of
4
24.7
9.853
881,342
8,081.8
3,665.9
42.2%
5
28.2
9.777
964,613
8,776.6
3,981.1
1
18.2
13.974
1,057,463
9,337.4
4,235.4
LDGT1
2
19.1
13.870
2,754,563
24,141.4
10,950.6
with VMT
3
24.4
13.455
1,711,101
14,547.7
6,598.8
mix of
4
24.7
13.443
881,342
7,486.6
3,395.9
28.7%
5
28.2
13.347
964,613
8,135.6
3,690.3
1
18.2
15.262
1,057,463
4,753.9
2,156.4
LDGT2
2
19.1
15.127
2,754,563
12,273.8
5,567.4
with VMT
3
24.4
14.628
1,711,101
7,372.8
3,344.3
mix of
4
24.7
14.607
881,342
3,792.1
1,720.1
13.4%
5
28.2
14.480
964,613
4,114.4
1,866.3
1
18.2
14.457
1,057,463
1,199.9
544.3
HDGV
2
19.1
13.758
2,754,563
2,974.5
1,349.2
with VMT
3
24.4
10.571
1,711,101
1,419.8
644.0
mix of
4
24.7
10.430
881,342
721.5
327.3
3.6%
5
28.2
9.095
964,613
688.6
312.3
1
18.2
1.803
1,057,463
9.2
4.2
LDDV
2
19.1
1.748
2,754,563
23.4
10.6
with VMT
3
24.4
1.490
1,711,101
12.4
5.6
mix of
4
24.7
1.479
881,342
6.3
2.9
0.2%
5
28.2
1.365
964,613
6.4
2.9
1
18.2
1.000
1,057,463
53.4
24.2
LDDT
2
19.1
0.965
2,754,563
134.2
60.9
with VMT
3
24.4
0.802
1,711,101
69.3
31.4
mix of
4
24.7
0.795
881,342
35.4
16.0
2.3%
5
28.2
0.723
964,613
35.2
16.0
1
18.2
4.183
1,057,463
896.3
406.5
HDDV
2
19.1
3.991
2,754,563
2,227.5
1,010.4
with VMT
3
24.4
3.095
1,711,101
1,073.1
486.7
mix of
4
24.7
3.055
881,342
545.6
247.5
9.2%
5
28.2
2.661
964,613
520.1
235.9
1
18.2
15.100
1,057,463
176.0
79.8
MC
2
19.1
14.550
2,754,563
441.8
200.4
with VMT
3
24.4
12.080
1,711,101
227.9
103.4
mix of
4
24.7
11.980
881,342
116.4
52.8
0.5%
5
28.2
10.800
964,613
114.8
52.1

2002 Carbon Monoxide Periodic Emission Inventory

87

Maricopa County, AZ

Table 5.5–1. Daily CO emissions in the CO nonattainment area, by vehicle class, facility type and area type
(peak CO season day) (continued).
Vehicle
Area Speed
Emission
DVMT
Emissions
Emissions
Facility type
class
type (mph) factor (g/mi)
(miles)
(lb/day)
(kg/day)
1
12.9
11.118
197,199
2,040.4
925.5
LOCAL
LDGV
2
12.9
11.118
2,011,047
20,808.2
9,438.6
with VMT
3
12.9
11.118
2,590,190
26,800.6
12,156.8
mix of
4
12.9
11.118
1,706,405
17,656.1
8,008.8
42.2%
5
12.9
11.118
864,330
8,943.2
4,056.6
1
12.9
14.927
197,199
1,860.0
843.7
LDGT1
2
12.9
14.927
2,011,047
18,968.8
8,604.2
with VMT
3
12.9
14.927
2,590,190
24,431.4
11,082.1
mix of
4
12.9
14.927
1,706,405
16,095.3
7,300.8
28.7%
5
12.9
14.927
864,330
8,152.6
3,698.0
1
12.9
16.431
197,199
954.4
432.9
LDGT2
2
12.9
16.431
2,011,047
9,733.3
4,415.0
with VMT
3
12.9
16.431
2,590,190
12,536.3
5,686.5
mix of
4
12.9
16.431
1,706,405
8,258.9
3,746.2
13.4%
5
12.9
16.431
864,330
4,183.3
1,897.5
1
12.9
20.082
197,199
310.8
141.0
HDGV
2
12.9
20.082
2,011,047
3,169.9
1,437.8
with VMT
3
12.9
20.082
2,590,190
4,082.7
1,851.9
mix of
4
12.9
20.082
1,706,405
2,689.7
1,220.0
3.6%
5
12.9
20.082
864,330
1,362.4
618.0
1
12.9
2.236
197,199
2.1
1.0
LDDV
2
12.9
2.236
2,011,047
21.8
9.9
with VMT
3
12.9
2.236
2,590,190
28.1
12.7
mix of
4
12.9
2.236
1,706,405
18.5
8.4
0.2%
5
12.9
2.236
864,330
9.4
4.3
1
12.9
1.275
197,199
12.7
5.8
LDDT
2
12.9
1.275
2,011,047
129.5
58.7
with VMT
3
12.9
1.275
2,590,190
166.7
75.6
mix of
4
12.9
1.275
1,706,405
109.8
49.8
2.3%
5
12.9
1.275
864,330
55.6
25.2
1
12.9
5.688
197,199
227.3
103.1
HDDV
2
12.9
5.688
2,011,047
2,317.8
1,051.3
with VMT
3
12.9
5.688
2,590,190
2,985.2
1,354.1
mix of
4
12.9
5.688
1,706,405
1,966.7
892.1
9.2%
5
12.9
5.688
864,330
996.2
451.9
1
12.9
20.110
197,199
43.7
19.8
MC
2
12.9
20.110
2,011,047
445.8
202.2
with VMT
3
12.9
20.110
2,590,190
574.2
260.5
mix of
4
12.9
20.110
1,706,405
378.3
171.6
0.5%
5
12.9
20.110
864,330
191.6
86.9

2002 Carbon Monoxide Periodic Emission Inventory

88

Maricopa County, AZ

Table 5.5–2.
season day).

Daily CO emissions in Maricopa County, by vehicle class, facility type and area type (peak CO

Facility type

Vehicle
class

INTERSTATE,
FREEWAY,
and
EXPRESSWAY

LDGV
with VMT
mix of
42.2%
LDGT1
with VMT
mix of
28.7%
LDGT2
with VMT
mix of
13.4%
HDGV
with VMT
mix of
3.6%
LDDV
with VMT
mix of
0.2%
LDDT
with VMT
mix of
2.3%
HDDV
with VMT
mix of
9.2%
MC
with VMT
mix of
0.5%

Area
type
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5

Speed
(mph)
59.7
60.3
63.2
64.8
64.2
59.7
60.3
63.2
64.8
64.2
59.7
60.3
63.2
64.8
64.2
59.7
60.3
63.2
64.8
64.2
59.7
60.3
63.2
64.8
64.2
59.7
60.3
63.2
64.8
64.2
59.7
60.3
63.2
64.8
64.2
59.7
60.3
63.2
64.8
64.2

2002 Carbon Monoxide Periodic Emission Inventory

Emission
factor (g/mi)
12.446
12.496
12.526
12.526
12.526
16.382
16.442
16.483
16.483
16.483
17.857
17.928
17.969
17.969
17.969
10.036
10.289
10.450
10.450
10.450
1.258
1.268
1.275
1.275
1.275
0.655
0.661
0.666
0.666
0.666
2.287
2.324
2.349
2.349
2.349
16.110
16.790
17.230
17.230
17.230

89

DVMT
(miles)
1,140,342
9,137,049
6,302,894
4,570,910
5,718,846
1,140,342
9,137,049
6,302,894
4,570,910
5,718,846
1,140,342
9,137,049
6,302,894
4,570,910
5,718,846
1,140,342
9,137,049
6,302,894
4,570,910
5,718,846
1,140,342
9,137,049
6,302,894
4,570,910
5,718,846
1,140,342
9,137,049
6,302,894
4,570,910
5,718,846
1,140,342
9,137,049
6,302,894
4,570,910
5,718,846
1,140,342
9,137,049
6,302,894
4,570,910
5,718,846

Emissions
(lb/day)
13,208.0
106,262.3
73,477.5
53,286.5
66,668.8
11,804.6
94,931.3
65,647.8
47,608.3
59,564.7
5,998.2
48,251.3
33,360.4
24,193.2
30,269.1
898.3
7,378.8
5,170.0
3,749.3
4,690.9
7.0
56.2
39.0
28.3
35.4
37.7
304.9
211.9
153.7
192.3
528.4
4,302.6
2,999.9
2,175.6
2,721.9
202.5
1,691.2
1,197.2
868.2
1,086.3

Emissions
(kg/day)
5,991.2
48,200.6
33,329.4
24,170.7
30,241.0
5,354.6
43,060.8
29,777.9
21,595.1
27,018.5
2,720.8
21,886.8
15,132.3
10,974.0
13,730.1
407.5
3,347.0
2,345.1
1,700.7
2,127.8
3.2
25.5
17.7
12.8
16.0
17.1
138.3
96.1
69.7
87.2
239.7
1,951.6
1,360.8
986.8
1,234.7
91.9
767.1
543.0
393.8
492.7

Maricopa County, AZ

Table 5.5–2. Daily CO emissions in Maricopa County, by vehicle class, facility type and area type (peak CO
season day) (continued).
Vehicle
Area Speed
Emission
DVMT
Emissions
Emissions
Facility type
class
type (mph) factor (g/mi)
(miles)
(lb/day)
(kg/day)
1
30.3
9.753
1,098,337
9,969.5
4,522.1
PRINCIPAL
LDGV
2
34.4
9.832
8,922,876
81,642.3
37,032.9
ARTERIALS
with VMT
3
36.1
9.933
9,893,913
91,463.1
41,487.7
and
mix of
4
39.0
10.157
6,992,646
66,101.4
29,983.6
MINOR
42.2%
5
42.6
10.451
3,776,028
36,725.5
16,658.7
ARTERIALS
1
30.3
13.315
1,098,337
9,240.9
4,191.7
LDGT1
2
34.4
13.423
8,922,876
75,683.6
34,330.1
with VMT
3
36.1
13.544
9,893,913
84,675.4
38,408.7
mix of
4
39.0
13.816
6,992,646
61,049.4
27,692.0
28.7%
5
42.6
14.151
3,776,028
33,764.0
15,315.3
1
30.3
14.437
1,098,337
4,670.8
2,118.7
LDGT2
2
34.4
14.545
8,922,876
38,228.1
17,340.3
with VMT
3
36.1
14.685
9,893,913
42,798.7
19,413.5
mix of
4
39.0
14.989
6,992,646
30,873.3
14,004.1
13.4%
5
42.6
15.373
3,776,028
17,098.9
7,756.0
1
30.3
8.457
1,098,337
729.1
330.7
HDGV
2
34.4
7.578
8,922,876
5,307.4
2,407.4
with VMT
3
36.1
7.335
9,893,913
5,696.0
2,583.7
mix of
4
39.0
7.011
6,992,646
3,848.2
1,745.6
3.6%
5
42.6
6.829
3,776,028
2,024.0
918.1
1
30.3
1.311
1,098,337
7.0
3.2
LDDV
2
34.4
1.231
8,922,876
53.3
24.2
with VMT
3
36.1
1.207
9,893,913
57.9
26.3
mix of
4
39.0
1.173
6,992,646
39.8
18.0
0.2%
5
42.6
1.147
3,776,028
21.0
9.5
1
30.3
0.688
1,098,337
38.2
17.3
LDDT
2
34.4
0.638
8,922,876
287.4
130.4
with VMT
3
36.1
0.622
9,893,913
310.7
140.9
mix of
4
39.0
0.601
6,992,646
212.2
96.2
2.3%
5
42.6
0.584
3,776,028
111.3
50.5
1
30.3
2.472
1,098,337
550.1
249.5
HDDV
2
34.4
2.195
8,922,876
3,968.5
1,800.1
with VMT
3
36.1
2.110
9,893,913
4,230.0
1,918.7
mix of
4
39.0
1.993
6,992,646
2,823.8
1,280.9
9.2%
5
42.6
1.901
3,776,028
1,454.5
659.7
1
30.3
10.210
1,098,337
123.6
56.1
MC
2
34.4
9.250
8,922,876
909.9
412.7
with VMT
3
36.1
8.930
9,893,913
974.0
441.8
mix of
4
39.0
8.460
6,992,646
652.2
295.8
0.5%
5
42.6
8.040
3,776,028
334.7
151.8

2002 Carbon Monoxide Periodic Emission Inventory

90

Maricopa County, AZ

Table 5.5–2. Daily CO emissions in Maricopa County, by vehicle class, facility type and area type (peak CO
season day) (continued).
Vehicle
Area Speed
Emission
DVMT
Emissions
Emissions
Facility type
class
type (mph) factor (g/mi)
(miles)
(lb/day)
(kg/day)
1
18.2
10.314
1,057,463
10,150.3
4,604.2
COLLECTOR
LDGV
2
19.1
10.220
2,754,563
26,198.8
11,883.8
with VMT
3
24.4
9.873
1,711,101
15,722.5
7,131.7
mix of
4
24.7
9.853
881,342
8,081.8
3,665.9
42.2%
5
28.2
9.777
2,414,851
21,971.7
9,966.4
1
18.2
13.974
1,057,463
9,337.4
4,235.4
LDGT1
2
19.1
13.870
2,754,563
24,141.4
10,950.6
with VMT
3
24.4
13.455
1,711,101
14,547.7
6,598.8
mix of
4
24.7
13.443
881,342
7,486.6
3,395.9
28.7%
5
28.2
13.347
2,414,851
20,367.0
9,238.5
1
18.2
15.262
1,057,463
4,753.9
2,156.4
LDGT2
2
19.1
15.127
2,754,563
12,273.8
5,567.4
with VMT
3
24.4
14.628
1,711,101
7,372.8
3,344.3
mix of
4
24.7
14.607
881,342
3,792.1
1,720.1
13.4%
5
28.2
14.480
2,414,851
10,300.2
4,672.2
1
18.2
14.457
1,057,463
1,199.9
544.3
HDGV
2
19.1
13.758
2,754,563
2,974.5
1,349.2
with VMT
3
24.4
10.571
1,711,101
1,419.8
644.0
mix of
4
24.7
10.430
881,342
721.5
327.3
3.6%
5
28.2
9.095
2,414,851
1,723.8
781.9
1
18.2
1.803
1,057,463
9.2
4.2
LDDV
2
19.1
1.748
2,754,563
23.4
10.6
with VMT
3
24.4
1.490
1,711,101
12.4
5.6
mix of
4
24.7
1.479
881,342
6.3
2.9
0.2%
5
28.2
1.365
2,414,851
16.0
7.3
1
18.2
1.000
1,057,463
53.4
24.2
LDDT
2
19.1
0.965
2,754,563
134.2
60.9
with VMT
3
24.4
0.802
1,711,101
69.3
31.4
mix of
4
24.7
0.795
881,342
35.4
16.0
2.3%
5
28.2
0.723
2,414,851
88.2
40.0
1
18.2
4.183
1,057,463
896.3
406.5
HDDV
2
19.1
3.991
2,754,563
2,227.5
1,010.4
with VMT
3
24.4
3.095
1,711,101
1,073.1
486.7
mix of
4
24.7
3.055
881,342
545.6
247.5
9.2%
5
28.2
2.661
2,414,851
1,302.0
590.6
1
18.2
15.100
1,057,463
176.0
79.8
MC
2
19.1
14.550
2,754,563
441.8
200.4
with VMT
3
24.4
12.080
1,711,101
227.9
103.4
mix of
4
24.7
11.980
881,342
116.4
52.8
0.5%
5
28.2
10.800
2,414,851
287.5
130.4

2002 Carbon Monoxide Periodic Emission Inventory

91

Maricopa County, AZ

Table 5.5–2. Daily CO emissions in Maricopa County, by vehicle class, facility type and area type (peak CO
season day) (continued).
Vehicle
Area Speed
Emission
DVMT
Emissions
Emissions
Facility type
class
type (mph) factor (g/mi)
(miles)
(lb/day)
(kg/day)
1
12.9
11.118
197,199
2,040.4
925.5
LOCAL
LDGV
2
12.9
11.118
2,011,047
20,808.2
9,438.6
with VMT
3
12.9
11.118
2,590,190
26,800.6
12,156.8
mix of
4
12.9
11.118
1,706,405
17,656.1
8,008.8
42.2%
5
12.9
11.118
864,330
8,943.2
4,056.6
1
12.9
14.927
197,199
1,860.0
843.7
LDGT1
2
12.9
14.927
2,011,047
18,968.8
8,604.2
with VMT
3
12.9
14.927
2,590,190
24,431.4
11,082.1
mix of
4
12.9
14.927
1,706,405
16,095.3
7,300.8
28.7%
5
12.9
14.927
864,330
8,152.6
3,698.0
1
12.9
16.431
197,199
954.4
432.9
LDGT2
2
12.9
16.431
2,011,047
9,733.3
4,415.0
with VMT
3
12.9
16.431
2,590,190
12,536.3
5,686.5
mix of
4
12.9
16.431
1,706,405
8,258.9
3,746.2
13.4%
5
12.9
16.431
864,330
4,183.3
1,897.5
1
12.9
20.082
197,199
310.8
141.0
HDGV
2
12.9
20.082
2,011,047
3,169.9
1,437.8
with VMT
3
12.9
20.082
2,590,190
4,082.7
1,851.9
mix of
4
12.9
20.082
1,706,405
2,689.7
1,220.0
3.6%
5
12.9
20.082
864,330
1,362.4
618.0
1
12.9
2.236
197,199
2.1
1.0
LDDV
2
12.9
2.236
2,011,047
21.8
9.9
with VMT
3
12.9
2.236
2,590,190
28.1
12.7
mix of
4
12.9
2.236
1,706,405
18.5
8.4
0.2%
5
12.9
2.236
864,330
9.4
4.3
1
12.9
1.275
197,199
12.7
5.8
LDDT
2
12.9
1.275
2,011,047
129.5
58.7
with VMT
3
12.9
1.275
2,590,190
166.7
75.6
mix of
4
12.9
1.275
1,706,405
109.8
49.8
2.3%
5
12.9
1.275
864,330
55.6
25.2
1
12.9
5.688
197,199
227.3
103.1
HDDV
2
12.9
5.688
2,011,047
2,317.8
1,051.3
with VMT
3
12.9
5.688
2,590,190
2,985.2
1,354.1
mix of
4
12.9
5.688
1,706,405
1,966.7
892.1
9.2%
5
12.9
5.688
864,330
996.2
451.9
1
12.9
20.110
197,199
43.7
19.8
MC
2
12.9
20.110
2,011,047
445.8
202.2
with VMT
3
12.9
20.110
2,590,190
574.2
260.5
mix of
4
12.9
20.110
1,706,405
378.3
171.6
0.5%
5
12.9
20.110
864,330
191.6
86.9

2002 Carbon Monoxide Periodic Emission Inventory

92

Maricopa County, AZ

Table 5.5–3. Daily CO emissions in the CO nonattainment area, by vehicle class, facility type and area type
(annual average daily traffic).
Vehicle
Area Speed
Emission
DVMT
Emissions
Emissions
Facility type
class
type (mph) factor (g/mi)
(miles)
(lb/day)
(kg/day)
1
59.7
13.108
1,129,051
14,710.1
6,672.5
INTERSTATE,
LDGV
2
60.3
13.177
9,046,583
118,484.5
53,744.6
FREEWAY,
with VMT
3
63.2
13.222
6,240,489
82,011.2
37,200.3
and
mix of
4
64.8
13.222
4,525,653
59,475.2
26,977.9
EXPRESSWAY
45.1%
5
64.2
13.222
2,678,544
35,200.8
15,967.1
1
59.7
16.711
1,129,051
11,737.2
5,324.0
LDGT1
2
60.3
16.788
9,046,583
94,474.3
42,853.5
with VMT
3
63.2
16.840
6,240,489
65,373.4
29,653.4
mix of
4
64.8
16.840
4,525,653
47,409.3
21,504.9
28.2%
5
64.2
16.840
2,678,544
28,059.6
12,727.8
1
59.7
18.807
1,129,051
5,223.8
2,369.5
LDGT2
2
60.3
18.890
9,046,583
42,041.0
19,069.8
with VMT
3
63.2
18.943
6,240,489
29,081.1
13,191.2
mix of
4
64.8
18.943
4,525,653
21,089.8
9,566.3
11.2%
5
64.2
18.943
2,678,544
12,482.2
5,661.9
1
59.7
12.791
1,129,051
1,133.4
514.1
HDGV
2
60.3
13.109
9,046,583
9,306.8
4,221.6
with VMT
3
63.2
13.317
6,240,489
6,521.7
2,958.2
mix of
4
64.8
13.317
4,525,653
4,729.6
2,145.3
3.6%
5
64.2
13.317
2,678,544
2,799.2
1,269.7
1
59.7
1.243
1,129,051
6.8
3.1
LDDV
2
60.3
1.254
9,046,583
55.0
25.0
with VMT
3
63.2
1.261
6,240,489
38.2
17.3
mix of
4
64.8
1.261
4,525,653
27.7
12.6
0.2%
5
64.2
1.261
2,678,544
16.4
7.4
1
59.7
0.664
1,129,051
35.7
16.2
LDDT
2
60.3
0.671
9,046,583
288.8
131.0
with VMT
3
63.2
0.675
6,240,489
200.6
91.0
mix of
4
64.8
0.675
4,525,653
145.5
66.0
2.2%
5
64.2
0.675
2,678,544
86.1
39.0
1
59.7
2.449
1,129,051
554.1
251.3
HDDV
2
60.3
2.489
9,046,583
4,511.0
2,046.2
with VMT
3
63.2
2.515
6,240,489
3,144.3
1,426.2
mix of
4
64.8
2.515
4,525,653
2,280.2
1,034.3
9.1%
5
64.2
2.515
2,678,544
1,349.6
612.2
1
59.7
21.115
1,129,051
268.0
121.6
MC
2
60.3
22.030
9,046,583
2,240.5
1,016.3
with VMT
3
63.2
22.630
6,240,489
1,587.6
720.2
mix of
4
64.8
22.630
4,525,653
1,151.4
522.3
0.5%
5
64.2
22.630
2,678,544
681.4
309.1

2002 Carbon Monoxide Periodic Emission Inventory

93

Maricopa County, AZ

Table 5.5–3. Daily CO emissions in the CO nonattainment area, by vehicle class, facility type and area type
(annual average daily traffic) (continued).
Vehicle
Area Speed
Emission
DVMT
Emissions
Emissions
Facility type
class
type (mph) factor (g/mi)
(miles)
(lb/day)
(kg/day)
1
30.3
9.686
1,087,462
10,469.1
4,748.8
PRINCIPAL
LDGV
2
34.4
9.835
8,834,531
86,363.5
39,174.5
ARTERIALS
with VMT
3
36.1
9.982
9,795,953
97,190.5
44,085.6
and
mix of
4
39.0
10.157
6,923,412
69,893.5
31,703.7
MINOR
45.1%
5
42.6
10.538
2,670,291
27,969.8
12,687.1
ARTERIALS
1
30.3
12.995
1,087,462
8,791.1
3,987.7
LDGT1
2
34.4
13.205
8,834,531
72,572.5
32,918.9
with VMT
3
36.1
13.375
9,795,953
81,506.2
36,971.2
mix of
4
39.0
13.593
6,923,412
58,544.9
26,556.0
28.2%
5
42.6
14.022
2,670,291
23,291.6
10,565.1
1
30.3
14.894
1,087,462
3,984.5
1,807.4
LDGT2
2
34.4
15.091
8,834,531
32,797.5
14,876.9
with VMT
3
36.1
15.270
9,795,953
36,798.8
16,691.9
mix of
4
39.0
15.509
6,923,412
26,415.6
11,982.1
11.2%
5
42.6
15.966
2,670,291
10,488.4
4,757.5
1
30.3
10.773
1,087,462
919.4
417.0
HDGV
2
34.4
9.660
8,834,531
6,697.0
3,037.8
with VMT
3
36.1
9.346
9,795,953
7,184.5
3,258.9
mix of
4
39.0
8.936
6,923,412
4,854.9
2,202.2
3.6%
5
42.6
8.701
2,670,291
1,823.4
827.1
1
30.3
1.296
1,087,462
6.8
3.1
LDDV
2
34.4
1.217
8,834,531
52.1
23.6
with VMT
3
36.1
1.193
9,795,953
56.7
25.7
mix of
4
39.0
1.160
6,923,412
38.9
17.7
0.2%
5
42.6
1.133
2,670,291
14.7
6.7
1
30.3
0.698
1,087,462
36.1
16.4
LDDT
2
34.4
0.647
8,834,531
272.1
123.4
with VMT
3
36.1
0.631
9,795,953
294.2
133.4
mix of
4
39.0
0.609
6,923,412
200.8
91.1
2.2%
5
42.6
0.592
2,670,291
75.3
34.1
1
30.3
2.647
1,087,462
576.7
261.6
HDDV
2
34.4
2.350
8,834,531
4,160.2
1,887.1
with VMT
3
36.1
2.260
9,795,953
4,435.5
2,012.0
mix of
4
39.0
2.134
6,923,412
2,960.6
1,342.9
9.1%
5
42.6
2.036
2,670,291
1,089.2
494.1
1
30.3
13.080
1,087,462
159.9
72.5
MC
2
34.4
11.765
8,834,531
1,168.5
530.1
with VMT
3
36.1
11.328
9,795,953
1,247.6
565.9
mix of
4
39.0
10.694
6,923,412
832.4
377.6
0.5%
5
42.6
10.114
2,670,291
303.6
137.7

2002 Carbon Monoxide Periodic Emission Inventory

94

Maricopa County, AZ

Table 5.5–3. Daily CO emissions in the CO nonattainment area, by vehicle class, facility type and area type
(annual average daily traffic) (continued).
Vehicle
Area Speed
Emission
DVMT
Emissions
Emissions
Facility type
class
type (mph) factor (g/mi)
(miles)
(lb/day)
(kg/day)
1
18.2
10.040
1,046,993
10,448.3
4,739.3
COLLECTOR
LDGV
2
19.1
9.940
2,727,290
26,946.0
12,222.7
with VMT
3
24.4
9.609
1,694,159
16,180.2
7,339.3
mix of
4
24.7
9.595
872,616
8,321.6
3,774.7
45.1%
5
28.2
9.559
955,062
9,074.1
4,116.0
1
18.2
13.268
1,046,993
8,641.7
3,919.9
LDGT1
2
19.1
13.167
2,727,290
22,338.1
10,132.5
with VMT
3
24.4
12.875
1,694,159
13,568.5
6,154.7
mix of
4
24.7
12.863
872,616
6,982.4
3,167.2
28.2%
5
28.2
12.859
955,062
7,639.7
3,465.4
1
18.2
15.380
1,046,993
3,961.5
1,796.9
LDGT2
2
19.1
15.251
2,727,290
10,232.5
4,641.4
with VMT
3
24.4
14.841
1,694,159
6,185.5
2,805.7
mix of
4
24.7
14.827
872,616
3,182.9
1,443.8
11.2%
5
28.2
14.777
955,062
3,472.0
1,574.9
1
18.2
18.423
1,046,993
1,513.7
686.6
HDGV
2
19.1
17.524
2,727,290
3,750.6
1,701.3
with VMT
3
24.4
13.463
1,694,159
1,789.9
811.9
mix of
4
24.7
13.282
872,616
909.5
412.6
3.6%
5
28.2
11.581
955,062
868.0
393.7
1
18.2
1.786
1,046,993
9.1
4.1
LDDV
2
19.1
1.731
2,727,290
22.9
10.4
with VMT
3
24.4
1.474
1,694,159
12.1
5.5
mix of
4
24.7
1.463
872,616
6.2
2.8
0.2%
5
28.2
1.350
955,062
6.3
2.8
1
18.2
1.015
1,046,993
50.6
23.0
LDDT
2
19.1
0.979
2,727,290
127.2
57.7
with VMT
3
24.4
0.813
1,694,159
65.6
29.8
mix of
4
24.7
0.806
872,616
33.5
15.2
2.2%
5
28.2
0.733
955,062
33.3
15.1
1
18.2
4.479
1,046,993
939.7
426.3
HDDV
2
19.1
4.274
2,727,290
2,335.5
1,059.4
with VMT
3
24.4
3.314
1,694,159
1,125.0
510.3
mix of
4
24.7
3.271
872,616
572.0
259.5
9.1%
5
28.2
2.849
955,062
545.3
247.3
1
18.2
19.735
1,046,993
232.3
105.4
MC
2
19.1
18.983
2,727,290
582.0
264.0
with VMT
3
24.4
15.626
1,694,159
297.6
135.0
mix of
4
24.7
15.480
872,616
151.9
68.9
0.5%
5
28.2
13.874
955,062
149.0
67.6

2002 Carbon Monoxide Periodic Emission Inventory

95

Maricopa County, AZ

Table 5.5–3. Daily CO emissions in the CO nonattainment area, by vehicle class, facility type and area type
(annual average daily traffic) (continued).
Vehicle
Area Speed
Emission
DVMT
Emissions
Emissions
Facility type
class
type (mph) factor (g/mi)
(miles)
(lb/day)
(kg/day)
1
12.9
10.904
195,247
2,116.1
959.8
LOCAL
LDGV
2
12.9
10.904
1,991,136
21,579.8
9,788.6
with VMT
3
12.9
10.904
2,564,545
27,794.3
12,607.5
mix of
4
12.9
10.904
1,689,510
18,310.8
8,305.8
45.1%
5
12.9
10.904
855,772
9,274.8
4,207.0
1
12.9
14.157
195,247
1,719.5
780.0
LDGT1
2
12.9
14.157
1,991,136
17,535.4
7,954.1
with VMT
3
12.9
14.157
2,564,545
22,585.3
10,244.7
mix of
4
12.9
14.157
1,689,510
14,879.1
6,749.1
28.2%
5
12.9
14.157
855,772
7,536.6
3,418.6
1
12.9
16.521
195,247
793.5
360.0
LDGT2
2
12.9
16.521
1,991,136
8,092.6
3,670.8
with VMT
3
12.9
16.521
2,564,545
10,423.1
4,727.9
mix of
4
12.9
16.521
1,689,510
6,866.7
3,114.7
11.2%
5
12.9
16.521
855,772
3,478.1
1,577.7
1
12.9
25.590
195,247
392.1
177.9
HDGV
2
12.9
25.590
1,991,136
3,998.6
1,813.8
with VMT
3
12.9
25.590
2,564,545
5,150.1
2,336.1
mix of
4
12.9
25.590
1,689,510
3,392.9
1,539.0
3.6%
5
12.9
25.590
855,772
1,718.6
779.5
1
12.9
2.216
195,247
2.1
1.0
LDDV
2
12.9
2.216
1,991,136
21.4
9.7
with VMT
3
12.9
2.216
2,564,545
27.6
12.5
mix of
4
12.9
2.216
1,689,510
18.2
8.2
0.2%
5
12.9
2.216
855,772
9.2
4.2
1
12.9
1.294
195,247
12.0
5.5
LDDT
2
12.9
1.294
1,991,136
122.7
55.6
with VMT
3
12.9
1.294
2,564,545
158.0
71.7
mix of
4
12.9
1.294
1,689,510
104.1
47.2
2.2%
5
12.9
1.294
855,772
52.7
23.9
1
12.9
6.090
195,247
238.3
108.1
HDDV
2
12.9
6.090
1,991,136
2,429.9
1,102.2
with VMT
3
12.9
6.090
2,564,545
3,129.7
1,419.6
mix of
4
12.9
6.090
1,689,510
2,061.8
935.2
9.1%
5
12.9
6.090
855,772
1,044.4
473.7
1
12.9
26.555
195,247
58.3
26.4
MC
2
12.9
26.555
1,991,136
594.4
269.6
with VMT
3
12.9
26.555
2,564,545
765.6
347.3
mix of
4
12.9
26.555
1,689,510
504.4
228.8
0.5%
5
12.9
26.555
855,772
255.5
115.9

2002 Carbon Monoxide Periodic Emission Inventory

96

Maricopa County, AZ

Table 5.5–4. Daily CO emissions in Maricopa County, by vehicle class, facility type and area type (annual
average daily traffic).
Vehicle
Area Speed
Emission
DVMT
Emissions
Emissions
Facility type
class
type (mph) factor (g/mi)
(miles)
(lb/day)
(kg/day)
1
59.7
13.108
1,129,051
14,710.1
6,672.5
INTERSTATE,
LDGV
2
60.3
13.177
9,046,583
118,484.5
53,744.6
FREEWAY,
with VMT
3
63.2
13.222
6,240,489
82,011.2
37,200.3
and
mix of
4
64.8
13.222
4,525,653
59,475.2
26,977.9
EXPRESSWAY
45.1%
5
64.2
13.222
5,662,224
74,411.7
33,753.2
1
59.7
16.711
1,129,051
11,737.2
5,324.0
LDGT1
2
60.3
16.788
9,046,583
94,474.3
42,853.5
with VMT
3
63.2
16.840
6,240,489
65,373.4
29,653.4
mix of
4
64.8
16.840
4,525,653
47,409.3
21,504.9
28.2%
5
64.2
16.840
5,662,224
59,315.7
26,905.6
1
59.7
18.807
1,129,051
5,223.8
2,369.5
LDGT2
2
60.3
18.890
9,046,583
42,041.0
19,069.8
with VMT
3
63.2
18.943
6,240,489
29,081.1
13,191.2
mix of
4
64.8
18.943
4,525,653
21,089.8
9,566.3
11.2%
5
64.2
18.943
5,662,224
26,386.3
11,968.8
1
59.7
12.791
1,129,051
1,133.4
514.1
HDGV
2
60.3
13.109
9,046,583
9,306.8
4,221.6
with VMT
3
63.2
13.317
6,240,489
6,521.7
2,958.2
mix of
4
64.8
13.317
4,525,653
4,729.6
2,145.3
3.6%
5
64.2
13.317
5,662,224
5,917.3
2,684.1
1
59.7
1.243
1,129,051
6.8
3.1
LDDV
2
60.3
1.254
9,046,583
55.0
25.0
with VMT
3
63.2
1.261
6,240,489
38.2
17.3
mix of
4
64.8
1.261
4,525,653
27.7
12.6
0.2%
5
64.2
1.261
5,662,224
34.6
15.7
1
59.7
0.664
1,129,051
35.7
16.2
LDDT
2
60.3
0.671
9,046,583
288.8
131.0
with VMT
3
63.2
0.675
6,240,489
200.6
91.0
mix of
4
64.8
0.675
4,525,653
145.5
66.0
2.2%
5
64.2
0.675
5,662,224
182.0
82.5
1
59.7
2.449
1,129,051
554.1
251.3
HDDV
2
60.3
2.489
9,046,583
4,511.0
2,046.2
with VMT
3
63.2
2.515
6,240,489
3,144.3
1,426.2
mix of
4
64.8
2.515
4,525,653
2,280.2
1,034.3
9.1%
5
64.2
2.515
5,662,224
2,852.9
1,294.1
1
59.7
21.115
1,129,051
268.0
121.6
MC
2
60.3
22.030
9,046,583
2,240.5
1,016.3
with VMT
3
63.2
22.630
6,240,489
1,587.6
720.2
mix of
4
64.8
22.630
4,525,653
1,151.4
522.3
0.5%
5
64.2
22.630
5,662,224
1,440.5
653.4

2002 Carbon Monoxide Periodic Emission Inventory

97

Maricopa County, AZ

Table 5.5–4. Daily CO emissions in Maricopa County by vehicle class, facility type and area type (annual
average daily traffic) (continued).
Vehicle
Area Speed
Emission
DVMT
Emissions
Emissions
Facility type
class
type (mph) factor (g/mi)
(miles)
(lb/day)
(kg/day)
1
30.3
9.686
1,087,462
10,469.1
4,748.8
PRINCIPAL
LDGV
2
34.4
9.835
8,834,531
86,363.5
39,174.5
ARTERIALS
with VMT
3
36.1
9.982
9,795,953
97,190.5
44,085.6
and
mix of
4
39.0
10.157
6,923,412
69,893.5
31,703.7
MINOR
45.1%
5
42.6
10.538
3,738,642
39,160.1
17,763.0
ARTERIALS
1
30.3
12.995
1,087,462
8,791.1
3,987.7
LDGT1
2
34.4
13.205
8,834,531
72,572.5
32,918.9
with VMT
3
36.1
13.375
9,795,953
81,506.2
36,971.2
mix of
4
39.0
13.593
6,923,412
58,544.9
26,556.0
28.2%
5
42.6
14.022
3,738,642
32,610.3
14,792.0
1
30.3
14.894
1,087,462
3,984.5
1,807.4
LDGT2
2
34.4
15.091
8,834,531
32,797.5
14,876.9
with VMT
3
36.1
15.270
9,795,953
36,798.8
16,691.9
mix of
4
39.0
15.509
6,923,412
26,415.6
11,982.1
11.2%
5
42.6
15.966
3,738,642
14,684.6
6,661.0
1
30.3
10.773
1,087,462
919.4
417.0
HDGV
2
34.4
9.660
8,834,531
6,697.0
3,037.8
with VMT
3
36.1
9.346
9,795,953
7,184.5
3,258.9
mix of
4
39.0
8.936
6,923,412
4,854.9
2,202.2
3.6%
5
42.6
8.701
3,738,642
2,552.9
1,158.0
1
30.3
1.296
1,087,462
6.8
3.1
LDDV
2
34.4
1.217
8,834,531
52.1
23.6
with VMT
3
36.1
1.193
9,795,953
56.7
25.7
mix of
4
39.0
1.160
6,923,412
38.9
17.7
0.2%
5
42.6
1.133
3,738,642
20.5
9.3
1
30.3
0.698
1,087,462
36.1
16.4
LDDT
2
34.4
0.647
8,834,531
272.1
123.4
with VMT
3
36.1
0.631
9,795,953
294.2
133.4
mix of
4
39.0
0.609
6,923,412
200.8
91.1
2.2%
5
42.6
0.592
3,738,642
105.4
47.8
1
30.3
2.647
1,087,462
576.7
261.6
HDDV
2
34.4
2.350
8,834,531
4,160.2
1,887.1
with VMT
3
36.1
2.260
9,795,953
4,435.5
2,012.0
mix of
4
39.0
2.134
6,923,412
2,960.6
1,342.9
9.1%
5
42.6
2.036
3,738,642
1,524.9
691.7
1
30.3
13.080
1,087,462
159.9
72.5
MC
2
34.4
11.765
8,834,531
1,168.5
530.1
with VMT
3
36.1
11.328
9,795,953
1,247.6
565.9
mix of
4
39.0
10.694
6,923,412
832.4
377.6
0.5%
5
42.6
10.114
3,738,642
425.1
192.8

2002 Carbon Monoxide Periodic Emission Inventory

98

Maricopa County, AZ

Table 5.5–4. Daily CO emissions in Maricopa County by vehicle class, facility type and area type (annual
average daily traffic) (continued).
Vehicle
Area Speed
Emission
DVMT
Emissions
Emissions
Facility type
class
type (mph) factor (g/mi)
(miles)
(lb/day)
(kg/day)
1
18.2
10.040
1,046,993
10,448.3
4,739.3
COLLECTOR
LDGV
2
19.1
9.940
2,727,290
26,946.0
12,222.7
with VMT
3
24.4
9.609
1,694,159
16,180.2
7,339.3
mix of
4
24.7
9.595
872,616
8,321.6
3,774.7
45.1%
5
28.2
9.559
2,390,942
22,716.5
10,304.2
1
18.2
13.268
1,046,993
8,641.7
3,919.9
LDGT1
2
19.1
13.167
2,727,290
22,338.1
10,132.5
with VMT
3
24.4
12.875
1,694,159
13,568.5
6,154.7
mix of
4
24.7
12.863
872,616
6,982.4
3,167.2
28.2%
5
28.2
12.859
2,390,942
19,125.5
8,675.3
1
18.2
15.380
1,046,993
3,961.5
1,796.9
LDGT2
2
19.1
15.251
2,727,290
10,232.5
4,641.4
with VMT
3
24.4
14.841
1,694,159
6,185.5
2,805.7
mix of
4
24.7
14.827
872,616
3,182.9
1,443.8
11.2%
5
28.2
14.777
2,390,942
8,691.9
3,942.6
1
18.2
18.423
1,046,993
1,513.7
686.6
HDGV
2
19.1
17.524
2,727,290
3,750.6
1,701.3
with VMT
3
24.4
13.463
1,694,159
1,789.9
811.9
mix of
4
24.7
13.282
872,616
909.5
412.6
3.6%
5
28.2
11.581
2,390,942
2,173.0
985.7
1
18.2
1.786
1,046,993
9.1
4.1
LDDV
2
19.1
1.731
2,727,290
22.9
10.4
with VMT
3
24.4
1.474
1,694,159
12.1
5.5
mix of
4
24.7
1.463
872,616
6.2
2.8
0.2%
5
28.2
1.350
2,390,942
15.7
7.1
1
18.2
1.015
1,046,993
50.6
23.0
LDDT
2
19.1
0.979
2,727,290
127.2
57.7
with VMT
3
24.4
0.813
1,694,159
65.6
29.8
mix of
4
24.7
0.806
872,616
33.5
15.2
2.2%
5
28.2
0.733
2,390,942
83.5
37.9
1
18.2
4.479
1,046,993
939.7
426.3
HDDV
2
19.1
4.274
2,727,290
2,335.5
1,059.4
with VMT
3
24.4
3.314
1,694,159
1,125.0
510.3
mix of
4
24.7
3.271
872,616
572.0
259.5
9.1%
5
28.2
2.849
2,390,942
1,365.0
619.2
1
18.2
19.735
1,046,993
232.3
105.4
MC
2
19.1
18.983
2,727,290
582.0
264.0
with VMT
3
24.4
15.626
1,694,159
297.6
135.0
mix of
4
24.7
15.480
872,616
151.9
68.9
0.5%
5
28.2
13.874
2,390,942
372.9
169.2

2002 Carbon Monoxide Periodic Emission Inventory

99

Maricopa County, AZ

Table 5.5–4. Daily CO emissions in Maricopa County by vehicle class, facility type and area type (annual
average daily traffic) (continued).
Vehicle
Area Speed
Emission
DVMT
Emissions
Emissions
Facility type
class
type (mph) factor (g/mi)
(miles)
(lb/day)
(kg/day)
1
12.9
10.904
195,247
2,116.1
959.8
LOCAL
LDGV
2
12.9
10.904
1,991,136
21,579.8
9,788.6
with VMT
3
12.9
10.904
2,564,545
27,794.3
12,607.5
mix of
4
12.9
10.904
1,689,510
18,310.8
8,305.8
45.1%
5
12.9
10.904
1,422,562
15,417.6
6,993.4
1
12.9
14.157
195,247
1,719.5
780.0
LDGT1
2
12.9
14.157
1,991,136
17,535.4
7,954.1
with VMT
3
12.9
14.157
2,564,545
22,585.3
10,244.7
mix of
4
12.9
14.157
1,689,510
14,879.1
6,749.1
28.2%
5
12.9
14.157
1,422,562
12,528.1
5,682.8
1
12.9
16.521
195,247
793.5
360.0
LDGT2
2
12.9
16.521
1,991,136
8,092.6
3,670.8
with VMT
3
12.9
16.521
2,564,545
10,423.1
4,727.9
mix of
4
12.9
16.521
1,689,510
6,866.7
3,114.7
11.2%
5
12.9
16.521
1,422,562
5,781.7
2,622.6
1
12.9
25.590
195,247
392.1
177.9
HDGV
2
12.9
25.590
1,991,136
3,998.6
1,813.8
with VMT
3
12.9
25.590
2,564,545
5,150.1
2,336.1
mix of
4
12.9
25.590
1,689,510
3,392.9
1,539.0
3.6%
5
12.9
25.590
1,422,562
2,856.8
1,295.8
1
12.9
2.216
195,247
2.1
1.0
LDDV
2
12.9
2.216
1,991,136
21.4
9.7
with VMT
3
12.9
2.216
2,564,545
27.6
12.5
mix of
4
12.9
2.216
1,689,510
18.2
8.2
0.2%
5
12.9
2.216
1,422,562
15.3
6.9
1
12.9
1.294
195,247
12.0
5.5
LDDT
2
12.9
1.294
1,991,136
122.7
55.6
with VMT
3
12.9
1.294
2,564,545
158.0
71.7
mix of
4
12.9
1.294
1,689,510
104.1
47.2
2.2%
5
12.9
1.294
1,422,562
87.6
39.8
1
12.9
6.090
195,247
238.3
108.1
HDDV
2
12.9
6.090
1,991,136
2,429.9
1,102.2
with VMT
3
12.9
6.090
2,564,545
3,129.7
1,419.6
mix of
4
12.9
6.090
1,689,510
2,061.8
935.2
9.1%
5
12.9
6.090
1,422,562
1,736.1
787.5
1
12.9
26.555
195,247
58.3
26.4
MC
2
12.9
26.555
1,991,136
594.4
269.6
with VMT
3
12.9
26.555
2,564,545
765.6
347.3
mix of
4
12.9
26.555
1,689,510
504.4
228.8
0.5%
5
12.9
26.555
1,422,562
424.7
192.6

2002 Carbon Monoxide Periodic Emission Inventory

100

Maricopa County, AZ

5.6

Summary of CO emissions from onroad mobile sources

Tables 5.6–1 through 5.6–4 summarize the calculated CO emissions by vehicle class, area, and
facility type. Total daily CO emissions from onroad mobile sources for the CO nonattainment
area in the 2002 carbon monoxide season are estimated to be 799,751 kilograms per day or
1,763,151 pounds per day. Total CO emissions from daily onroad mobile sources for all of
Maricopa County for the 2002 carbon monoxide season are estimated to be 873,558 kilograms
per day or 1,925,867 pounds per day.
Similarly, total CO emissions were estimated for all of 2002. For the carbon monoxide
nonattainment area, onroad estimates are 322,867 English tons per year. For all of Maricopa
County, onroad emissions are estimated to be 352,821 English tons per year.

Table 5.6–1. Daily CO emissions (kg/day) in the CO nonattainment area from onroad mobile sources by
vehicle class, area type and facility type (winter day).
Area
Vehicle class
Facility type type
LDGV LDGT1 LDGT2 HDGV LDDV LDDT
HDDV
MC TOTAL
1
5,991.2
5,354.6
2,720.8
407.5
3.2
17.1
239.7
91.9 14,825.8
INTERSTATE,
2
48,200.6 43,060.8 21,886.8 3,347.0
25.5
138.3
1,951.6
767.1 119,377.8
FREEWAY,
3
33,329.4 29,777.9 15,132.3 2,345.1
17.7
96.1
1,360.8
543.0 82,602.3
and
4
24,170.7 21,595.1 10,974.0 1,700.7
12.8
69.7
986.8
393.8 59,903.8
EXPRESSWAY 5
14,305.7 12,781.3
6,495.1 1,006.6
7.6
41.3
584.1
233.1 35,454.6
Total 125,997.5 112,569.6 57,209.0 8,806.9
66.7
362.5
5,123.0 2,029.0 312,164.3
PRINCIPAL
ARTERIAL
and
MINOR
ARTERIAL

COLLECTOR

LOCAL

GRAND
TOTALS:

1
4,522.1
4,191.7
2
37,032.9 34,330.1
3
41,487.7 38,408.7
4
29,983.6 27,692.0
5
11,898.3 10,938.8
Total 124,924.7 115,561.4

2,118.7
17,340.3
19,413.5
14,004.1
5,539.7
58,416.2

330.7
2,407.4
2,583.7
1,745.6
655.7
7,723.1

3.2
24.2
26.3
18.0
6.8
78.5

17.3
130.4
140.9
96.2
36.1
420.9

249.5
56.1 11,489.3
1,800.1
412.7 93,478.1
1,918.7
441.8 104,421.3
1,280.9
295.8 75,116.3
471.2
108.4 29,655.1
5,720.5 1,314.9 314,160.1

1
2
3
4
5
Total

4,604.2
11,883.8
7,131.7
3,665.9
3,981.1
31,266.6

4,235.4
10,950.6
6,598.8
3,395.9
3,690.3
28,871.1

2,156.4
5,567.4
3,344.3
1,720.1
1,866.3
14,654.5

544.3
1,349.2
644.0
327.3
312.3
3,177.2

4.2
10.6
5.6
2.9
2.9
26.2

24.2
60.9
31.4
16.0
16.0
148.5

406.5
1,010.4
486.7
247.5
235.9
2,387.1

79.8
200.4
103.4
52.8
52.1
488.5

12,055.1
31,033.3
18,346.0
9,428.4
10,156.9
81,019.7

1
2
3
4
5
Total

925.5
9,438.6
12,156.8
8,008.8
4,056.6
34,586.3

843.7
8,604.2
11,082.1
7,300.8
3,698.0
31,528.9

432.9
4,415.0
5,686.5
3,746.2
1,897.5
16,178.2

141.0
1,437.8
1,851.9
1,220.0
618.0
5,268.8

1.0
9.9
12.7
8.4
4.3
36.3

5.8
58.7
75.6
49.8
25.2
215.2

103.1
1,051.3
1,354.1
892.1
451.9
3,852.5

19.8
202.2
260.5
171.6
86.9
741.0

2,472.8
25,217.9
32,480.2
21,397.8
10,838.4
92,407.2

316,775.2 288,531.0 146,457.9 24,975.9

2002 Carbon Monoxide Periodic Emission Inventory

101

207.6 1,147.2

17,083.0 4,573.4 799,751.2

Maricopa County, AZ

Table 5.6–2. Daily CO emissions (kg day) in Maricopa County from onroad mobile sources by vehicle class,
area type and facility type (winter day).
Area
Vehicle class
Facility type type
LDGV LDGT1 LDGT2 HDGV LDDV LDDT
HDDV
MC TOTAL
1
5,991.2
5,354.6
2,720.8
407.5
3.2
17.1
239.7
91.9 14,825.8
INTERSTATE,
2
48,200.6 43,060.8 21,886.8 3,347.0
25.5
138.3
1,951.6
767.1 119,377.8
FREEWAY,
3
33,329.4 29,777.9 15,132.3 2,345.1
17.7
96.1
1,360.8
543.0 82,602.3
and
4
24,170.7 21,595.1 10,974.0 1,700.7
12.8
69.7
986.8
393.8 59,903.8
EXPRESSWAY 5
30,241.0 27,018.5 13,730.1 2,127.8
16.0
87.2
1,234.7
492.7 74,948.1
Total 141,932.9 126,806.9 64,443.9 9,928.1
75.2
408.5
5,773.6 2,288.6 351,657.8
PRINCIPAL
ARTERIAL
and
MINOR
ARTERIAL

COLLECTOR

LOCAL

GRAND
TOTALS:

1
4,522.1
4,191.7
2
37,032.9 34,330.1
3
41,487.7 38,408.7
4
29,983.6 27,692.0
5
16,658.7 15,315.3
Total 129,685.1 119,937.9

2,118.7
17,340.3
19,413.5
14,004.1
7,756.0
60,632.6

330.7
2,407.4
2,583.7
1,745.6
918.1
7,985.5

3.2
24.2
26.3
18.0
9.5
81.2

17.3
130.4
140.9
96.2
50.5
435.4

249.5
56.1 11,489.3
1,800.1
412.7 93,478.1
1,918.7
441.8 104,421.3
1,280.9
295.8 75,116.3
659.7
151.8 41,519.7
5,909.0 1,358.2 326,024.8

1
2
3
4
5
Total

4,604.2
11,883.8
7,131.7
3,665.9
9,966.4
37,251.9

4,235.4
10,950.6
6,598.8
3,395.9
9,238.5
34,419.2

2,156.4
5,567.4
3,344.3
1,720.1
4,672.2
17,460.4

544.3
1,349.2
644.0
327.3
781.9
3,646.7

4.2
10.6
5.6
2.9
7.3
30.5

24.2
60.9
31.4
16.0
40.0
172.6

406.5
1,010.4
486.7
247.5
590.6
2,741.8

79.8
200.4
103.4
52.8
130.4
566.8

12,055.1
31,033.3
18,346.0
9,428.4
25,427.2
96,290.0

1
2
3
4
5
Total

925.5
9,438.6
12,156.8
8,008.8
6,743.4
37,273.1

843.7
8,604.2
11,082.1
7,300.8
6,147.3
33,978.2

432.9
4,415.0
5,686.5
3,746.2
3,154.3
17,435.0

141.0
1,437.8
1,851.9
1,220.0
1,027.3
5,678.1

1.0
9.9
12.7
8.4
7.1
39.1

5.8
58.7
75.6
49.8
42.0
231.9

103.1
1,051.3
1,354.1
892.1
751.1
4,151.7

19.8
202.2
260.5
171.6
144.5
798.6

2,472.8
25,217.9
32,480.2
21,397.8
18,016.9
99,585.6

346,142.9 315,142.2 159,971.9 27,238.4

2002 Carbon Monoxide Periodic Emission Inventory

102

226.0 1,248.3

18,576.1 5,012.3 873,558.1

Maricopa County, AZ

Table 5.6–3. Daily CO emissions (kg/day) in the CO nonattainment area from onroad mobile sources by
vehicle class, area type and facility type (annual average day).
Area
Vehicle class
Facility type type
LDGV LDGT1 LDGT2 HDGV LDDV LDDT
HDDV
MC TOTAL
1
6,672.5
5,324.0
2,369.5
514.1
3.1
16.2
251.3
121.6 15,272.3
INTERSTATE,
2
53,744.6 42,853.5 19,069.8 4,221.6
25.0
131.0
2,046.2 1,016.3 123,107.9
FREEWAY,
3
37,200.3 29,653.4 13,191.2 2,958.2
17.3
91.0
1,426.2
720.2 85,257.7
and
4
26,977.9 21,504.9
9,566.3 2,145.3
12.6
66.0
1,034.3
522.3 61,829.6
EXPRESSWAY 5
15,967.1 12,727.8
5,661.9 1,269.7
7.4
39.0
612.2
309.1 36,594.3
Total 140,562.4 112,063.6 49,858.8 11,108.9
65.3
343.2
5,370.2 2,689.4 322,061.9
PRINCIPAL
ARTERIAL
and
MINOR
ARTERIAL

COLLECTOR

LOCAL

GRAND
TOTALS:

1
4,748.8
3,987.7
2
39,174.5 32,918.9
3
44,085.6 36,971.2
4
31,703.7 26,556.0
5
12,687.1 10,565.1
Total 132,399.6 110,998.8

1,807.4
14,876.9
16,691.9
11,982.1
4,757.5
50,115.9

417.0
3,037.8
3,258.9
2,202.2
827.1
9,742.9

3.1
23.6
25.7
17.7
6.7
76.8

16.4
123.4
133.4
91.1
34.1
398.5

261.6
72.5 11,314.5
1,887.1
530.1 92,572.3
2,012.0
565.9 103,744.6
1,342.9
377.6 74,273.2
494.1
137.7 29,509.3
5,997.6 1,683.8 311,413.9

1
2
3
4
5
Total

4,739.3
12,222.7
7,339.3
3,774.7
4,116.0
32,192.1

3,919.9
10,132.5
6,154.7
3,167.2
3,465.4
26,839.7

1,796.9
4,641.4
2,805.7
1,443.8
1,574.9
12,262.8

686.6
1,701.3
811.9
412.6
393.7
4,006.1

4.1
10.4
5.5
2.8
2.8
25.6

23.0
57.7
29.8
15.2
15.1
140.7

426.3
1,059.4
510.3
259.5
247.3
2,502.7

105.4
264.0
135.0
68.9
67.6
640.8

11,701.5
30,089.4
17,792.2
9,144.6
9,882.9
78,610.5

1
2
3
4
5
Total

959.8
9,788.6
12,607.5
8,305.8
4,207.0
35,868.7

780.0
7,954.1
10,244.7
6,749.1
3,418.6
29,146.4

360.0
3,670.8
4,727.9
3,114.7
1,577.7
13,451.1

177.9
1,813.8
2,336.1
1,539.0
779.5
6,646.3

1.0
9.7
12.5
8.2
4.2
35.6

5.5
55.6
71.7
47.2
23.9
203.9

108.1
1,102.2
1,419.6
935.2
473.7
4,038.9

26.4
269.6
347.3
228.8
115.9
988.0

2,418.5
24,664.4
31,767.3
20,928.1
10,600.5
90,378.9

341,022.9 279,048.5 125,688.5 31,504.3

2002 Carbon Monoxide Periodic Emission Inventory

103

203.3 1,086.3

17,909.5 6,002.0 802,465.3

Maricopa County, AZ

Table 5.6–4.
Daily CO emissions (kg/day) in Maricopa County from onroad mobile sources by vehicle
class, area type and facility type (annual average day).
Area
Vehicle class
Facility type type
LDGV LDGT1 LDGT2 HDGV LDDV LDDT
HDDV
MC TOTAL
1
6,672.5
5,324.0
2,369.5
514.1
3.1
16.2
251.3
121.6 15,272.3
INTERSTATE,
2
53,744.6 42,853.5 19,069.8 4,221.6
25.0
131.0
2,046.2 1,016.3 123,107.9
FREEWAY,
3
37,200.3 29,653.4 13,191.2 2,958.2
17.3
91.0
1,426.2
720.2 85,257.7
and
4
26,977.9 21,504.9
9,566.3 2,145.3
12.6
66.0
1,034.3
522.3 61,829.6
EXPRESSWAY 5
33,753.2 26,905.6 11,968.8 2,684.1
15.7
82.5
1,294.1
653.4 77,357.5
Total 158,348.5 126,241.4 56,165.7 12,523.3
73.6
386.7
6,052.1 3,033.7 362,825.0
PRINCIPAL
ARTERIAL
and
MINOR
ARTERIAL

COLLECTOR

LOCAL

GRAND
TOTALS:

1
4,748.8
3,987.7
2
39,174.5 32,918.9
3
44,085.6 36,971.2
4
31,703.7 26,556.0
5
17,763.0 14,792.0
Total 137,475.6 115,225.8

1,807.4
417.0
14,876.9 3,037.8
16,691.9 3,258.9
11,982.1 2,202.2
6,661.0 1,158.0
52,019.3 10,073.9

3.1
23.6
25.7
17.7
9.3
79.4

16.4
123.4
133.4
91.1
47.8
412.1

261.6
72.5 11,314.5
1,887.1
530.1 92,572.3
2,012.0
565.9 103,744.6
1,342.9
377.6 74,273.2
691.7
192.8 41,315.7
6,195.3 1,738.9 323,220.2

1
2
3
4
5
Total

4,739.3
12,222.7
7,339.3
3,774.7
10,304.2
38,380.3

3,919.9
10,132.5
6,154.7
3,167.2
8,675.3
32,049.7

1,796.9
4,641.4
2,805.7
1,443.8
3,942.6
14,630.5

686.6
1,701.3
811.9
412.6
985.7
4,598.0

4.1
10.4
5.5
2.8
7.1
29.9

23.0
57.7
29.8
15.2
37.9
163.5

426.3
1,059.4
510.3
259.5
619.2
2,874.6

105.4
264.0
135.0
68.9
169.2
742.4

11,701.5
30,089.4
17,792.2
9,144.6
24,741.1
93,468.8

1
2
3
4
5
Total

959.8
9,788.6
12,607.5
8,305.8
6,993.4
38,655.1

780.0
7,954.1
10,244.7
6,749.1
5,682.8
31,410.6

360.0
3,670.8
4,727.9
3,114.7
2,622.6
14,496.0

177.9
1,813.8
2,336.1
1,539.0
1,295.8
7,162.6

1.0
9.7
12.5
8.2
6.9
38.3

5.5
55.6
71.7
47.2
39.8
219.8

108.1
26.4
1,102.2
269.6
1,419.6
347.3
935.2
228.8
787.5
192.6
4,352.7 1,064.8

2,418.5
24,664.4
31,767.3
20,928.1
17,621.4
97,399.8

372,859.4 304,927.4 137,311.5 34,357.8

2002 Carbon Monoxide Periodic Emission Inventory

104

221.3 1,182.0

19,474.6 6,579.8 876,913.9

Maricopa County, AZ

5.7

Quality assurance process

5.7.1

VMT estimates

Normal quality assurance procedures, including extensive automated consistency checks, were
used by ADOT in developing the 2002 HPMS data. These data were submitted to the Federal
Highway Administration in October 2003.

5.7.2

Emission factor estimates

The quality assurance (QA) process performed on the MOBILE6.2 analyses included accuracy,
completeness, and reasonableness checks. For accuracy and completeness, a system was used
that included a two-layer, independent reviewer set-up. All hard copy and computer-based data
entries as well as all calculations procedures were checked independently for accuracy and
completeness by two different reviewers. Any errors found were corrected and the changes were
then rechecked by the reviewers.
The entire onroad mobile source portion of the 2002 periodic CO inventory was reviewed by
MAG staff that did not directly participate in its development. All comments were addressed.

5.7.3

Quality review of 2002 periodic CO emissions inventory

The draft onroad mobile source portion of the 2002 periodic carbon monoxide emissions
inventory was reviewed using published EPA quality review guidelines for base year emission
inventories (EPA Document 450/4-91-022, September 1991). The procedural review (Levels I,
II, and III) included checks for completeness, consistency, and the correct use of appropriate
procedures.
Additionally, the draft onroad mobile source portion of the 2002 periodic carbon monoxide
emissions inventory for the carbon monoxide nonattainment area was compared with the onroad
mobile source portions of the 1990, 1993, 1996, and 1999 base year and periodic emissions
inventories. The results are in Table 5.7–1. Estimates for Maricopa County in its entirety were
not prepared for previous inventories, so no comparison is possible.
Table 5.7–1. Comparison of CO emissions from onroad mobile sources and vehicle miles traveled (VMT) in
the CO nonattainment area, 1990–2002.
CO emissions from onroad
Vehicle miles
Year of analysis
mobile sources (lb/yr)
traveled (VMT)
1990
1,615,410
45,877,773
1993
1,220,223
48,153,240
1996
1,120,508
53,091,273
1999
1,080,829
57,853,980
2002
1,763,151
68,199,542

2002 Carbon Monoxide Periodic Emission Inventory

105

Maricopa County, AZ

While the VMT increases over time, the modeled onroad CO emissions decrease between 1990
and 1999 because of the implementation of control measures designed to reduce onroad emissions such as I/M program, cleaner gasoline, cleaner vehicle technologies, etc. This decline
would have continued if MOBILE5a had been used for the 2002 inventory. Significant increase
is modeled between 1999 and 2002 due to the use of MOBILE6.2 in the 2002 analysis versus
MOBILE5a in the 1999 and previous analyses. It is also important to note that the base case
emissions from the Serious Area CO Plan may not match those in the periodic inventories
because of a different year modeled and different modeling domain size.
As an additional QA check, the average miles per gallon estimate was derived using average
annual daily VMT estimates and gasoline sales from ADOT. The results of that QA check may
be found in Appendix 5.5.

5.8

References

MAG, 1986. 1986 Phoenix Urbanized Area Travel Speed Study, Parsons Brinkerhoff Quade &
Douglas, Inc., for MAG, October 1986.
MAG, 1990. Phoenix Travel Demand Model Update Project Final Report, MAG, January 1990.
MAG, 1995. 1993 Study of Travel Speed and Delay in the MAG Region, Lee Engineering, Inc.,
for MAG, January 1995.
MAG, 1995. Maricopa Association of Governments Highway Performance Monitoring System
Update, Lee Engineering, Inc., for MAG, January 1995.
MAG, 2000. 1998 MAG Regional Congestion Study, Traffic Research & Analysis, Inc. et al.
for MAG, September 2000.
Memorandum from Arizona Department of Environmental Quality, on Cutpoints for IM147 for
MOBILE6, May 2001.
Memorandum from William G. Laxton, US Environmental Protection Agency, OAQPS, on
Issues Associated with the 1990 Base Year Emission Inventory and Modeling, December
1991.
US DOT, 1987. Highway Performance Monitoring System Field Manual, US Department of
Transportation, Federal Highway Administration, December 1987.
US EPA, 1991. Emission Inventory Requirements for Carbon Monoxide State Implementation
Plans, EPA-450/4-91-011, March 1991.
US EPA, 1992. Procedures for Emission Inventory Preparation Volume IV: Mobile Sources,
EPA-450/4-81-026d (Revised), 1992.
US EPA, 1992. Quality Review Guidelines for 1990 Base Year Emission Inventories, EPA454/R-92-007, July 1992.
SAI, 1994. Revised Base Case and Demonstration of Attainment for Carbon Monoxide for
Maricopa County, Arizona, Systems Applications International, for MAG, February 1994.
US EPA, 2003. User's Guide to MOBILE6.1 and MOBILE6.2 (Mobile Source Emission Factor
Model), EPA420-R-03-010, August 2003.

2002 Carbon Monoxide Periodic Emission Inventory

106

Maricopa County, AZ