FINAL 

2003 AQMP APPENDIX III 

BASE AND FUTURE YEAR EMISSION INVENTORIES 

AUGUST 2003 
SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT 

GOVERNING BOARD 

Chairman: WILLIAM A. BURKE, Ed.D. 

 Speaker of the Assembly Appointee 

Vice Chairman: S. ROY WILSON, Ed.D. 

 Supervisor, Fourth District 

 Riverside County Representative 

MEMBERS:

FRED AGUIAR 

Supervisor, Fourth District 

San Bernardino County Representative 

MICHAEL D. ANTONOVICH 

Supervisor, Fifth District 

Los Angeles County Representative 

HAL BERNSON 

Councilmember, City of Los Angeles 

Cities Representative, Los Angeles County, Western Region 

JANE W. CARNEY 

Senate Rules Committee Appointee 

WILLIAM CRAYCRAFT 

Councilmember, City of Mission Viejo 

Cities Representative, Orange County 

BEATRICE LAPISTO-KIRTLEY 

Councilmember, City of Bradbury 

Cities Representative, Los Angeles County, Eastern Region 

RONALD O. LOVERIDGE 

Mayor, City of Riverside 

Cities Representative, Riverside County 

LEONARD PAULITZ 

Councilmember, City of Montclair 

Cities Representative, San Bernardino County 

JAMES SILVA 

Supervisor, Second District

Orange County Representative 

CYNTHIA VERDUGO –PERALTA 

Governor’s Appointee 

EXECUTIVE OFFICER

BARRY R. WALLERSTEIN, D.Env 

CONTRIBUTORS

Elaine Chang, DrPH 

Deputy Executive Officer 

Planning, Rule Development, Area Sources and Transportation 

Mike A. Nazemi 

Planning Manager 

Production

Boyajian, Candy 

McFarland, Maria

CALIFORNIA AIR RESOURCES BOARD

Robert Fletcher 

Division Chief 

Technical Support Division 

Linda Murchison 

Assistant Division Chief 

Randy Pasek Mark Carlock 

Branch Chief Branch Chief 

 

Bassett, Mark Said, Mervat 

Eckerle, Ed Sunico, Efren 

Hsiao, Kathy Woods, Mary 

Lester, Julia Wu, Robert 

Nakamura, Susan Yan, Susan 

Pirveysian, Zorik Zhang, Xinqiu 

 

Agrawal, Archana Johnson, Martin 

Asregadoo, Ray Lerch, Vivian 

Bhargava, Vijay Long, Jeff 

Calavita, Joe Patel, Dilip 

Table of Contents 

i 

Table of Contents 

CHAPTER 1 INVENTORY DEVELOPMENT 

Background .................................................................................................................1-1 

Air Contaminants ........................................................................................................1-2 

Inventory Source Category .........................................................................................1-7 

Stationary Sources ...........................................................................................1-7 

Point Sources ...................................................................................................1-7 

Area Sources ....................................................................................................1-8 

Mobile Sources .........................................................................................................1-15 

On-Road Mobile Sources...............................................................................1-15 

Off-Road Mobile Sources..............................................................................1-17 

Inventory Type..........................................................................................................1-20 

Average Annual Day Inventory.....................................................................1-20 

Planning Inventory.........................................................................................1-20 

CHAPTER 2 SUMMARIES OF EMISSIONS 

Baseline Emissions Inventories ..................................................................................2-1 

Base Year Emission Data............................................................................................2-1 

Future Year Emissions................................................................................................2-3 

Control Factors.................................................................................................2-3 

Growth Factors.................................................................................................2-6 

Future Year Emission Data............................................................................2-15 

Emission Trend Analysis ..........................................................................................2-15 

VOC Emissions..............................................................................................2-23 

NOx Emissions...............................................................................................2-24 

CO Emissions.................................................................................................2-24 

PM10 Emissions..............................................................................................2-24 

 Growth Impact ..........................................................................................................2-24 

Mobile and Area Source Credit Programs................................................................2-25 

Controlled Emissions Inventories.............................................................................2-27 

Emission Impacts of SCAQMD Programs ...............................................................2-27 

Hi-Low...........................................................................................................2-27 

RECLAIM Allocation....................................................................................2-27 

SIP Set Aside Accounts.................................................................................2-28 

Growth from New and Modified Sources .....................................................2-28 

Proposed Control Measures ......................................................................................2-36 

Control Efficiency/Control Factor.................................................................2-36 

Measure Impact Sources................................................................................2-37 

CEPA Emission Calculations ...................................................................................2-38 

 CARB Emission Data Reports System .....................................................................2-39 

 
APPENDIX III: Base and Future Year Emission Inventories 

ii 

REFERENCES

ATTACHMENT A Average Annual Emissions Summary by Major Source 

Category 

ATTACHMENT B Summer Emissions Summary by Major Source Category 

ATTACHMENT C Winter Emissions Summary by Major Source Category 

ATTACHMENT D Top 300 SCAB VOC and NOx Producers in 1997 

ATTACHMENT E On-Road Emissions by Category 

ATTACHMENT F Emissions from Diesel Fuel by Major Source Category 

LIST OF FIGURES

Figure 1-1: Comparison of Point Source Emissions between 1993 and 1997 ..........1-9 

Figure 1-2: Comparison of Area Source Emissions between 1993 and 1997 ..........1-9 

Figure 1-3: Comparison of On-Road Baseline Emissions between EMFAC7G and 

EMFAC2002 ................................................................................................1-17 

Figure 1-4: Comparison of Off-Road Baseline Emissions between 1997 AQMP and 

2003 AQMP ..................................................................................................1-19 

Figure 2-1: Comparison of Emissions Inventory of 1990 and 1997 .........................2-2 

Figure 2-2: Relative Contribution by Source Category 

to 1997 Emissions Inventory - Average Annual Day....................................2-16 

Figure 2-3: Relative Contribution by Source Category 

to 1997 Emissions Inventory - Planning Inventory.......................................2-17 

Figure 2-4: Relative Contribution by Source Category 

to 2010 Emissions Inventory - Average Annual Day....................................2-18 

Figure 2-5: Relative Contribution by Source Category 

to 2010 Emissions Inventory - Planning Inventory.......................................2-19 

Figure 2-6A: VOC Emission Trend by Source Category - 

Average Annual Day .....................................................................................2-20 
Table of Contents 

iii 

Figure 2-6B: VOC Emission Trend by Source Category - 

Summer Planning...........................................................................................2-20 

Figure 2-7A: NOx Emission Trend by Source Category - 

Annual Average Day .....................................................................................2-21 

Figure 2-7B: NOx Emission Trend by Source Category - 

Summer Planning...........................................................................................2-21 

Figure 2-8A: CO Emission Trend by Source Category - 

Annual Average Day .....................................................................................2-22 

Figure 2-8B: CO Emission Trend by Source Category - 

Summer Planning...........................................................................................2-22 

Figure 2-9: PM10 Emission Trend by Source Category - 

Annual Average Day .....................................................................................2-23 

LIST OF TABLES 

Table 1-1: District Adopted Rules and Associated Emission Reduction in the 2003 

AQMP Baseline ..............................................................................................1-3 

Table 1-2: Rules and Regulations Adopted by CARB/U.S. EPA Since 1997/1999 

AQMP..............................................................................................................1-5 

Table 1-3: List of Compounds Exempt in U.S. EPA's Definition of VOC; Included in 

CARB's Definition of ROG .............................................................................1-6 

Table 1-4: Comparison of 1993 and 1997 Major PM10 Sources Emissions............1-13 

Table 1-5: Changes in Ammonia Emissions Between 1995 and 1997....................1-14 

Table 2-1: Rules and Regulations Adopted/Amended by SCAQMD 

Between September 30, 1996 and October 31, 2002 ......................................2-4 

Table 2-2: Control Factors by District Rules with Post-1997 

Compliance Dates ............................................................................................2-5 

Table 2-3: Growth Surrogates by Source Category...................................................2-7 

Table 2-4: Baseline Socioeconomic Forecasts Used in the 2003 AQMP ...............2-11 

Table 2-5: Population Forecast by County in SCAB...............................................2-12 

Table 2-6: SIC Code Growth Factors by County for the Year 2010.......................2-13 

Table 2-7: SIC Code Growth Factors by County for the Year 2020.......................2-14 
APPENDIX III: Base and Future Year Emission Inventories 

iv 

Table 2-8: Growth Impact to 2010 Annual Average Emissions..............................2-25 

Table 2-9: Credit Rules and Associated Emissions.................................................2-26 

Table 2-10: Summary of Emissions Growth Set-Aside for the 2003 AQMP 

(Tons per Day) ...............................................................................................2-28 

Table 2-11: Annual Average Net Demand for ERCs in the Open Market..............2-30 

Table 2-12: 2010 Net Demand for ERCs in the Open Market ................................2-31 

Table 2-13: Annual Average Net Demand for Offsets in the AQMD's NSR 

Account..........................................................................................................2-32 

Table 2-14: 2010 Net Demand for ERCs in the AQMD's NSR Account ...............2-33 

Table 2-15: Total 2010 Net Demand from New and Modified Sources .................2-33 

Table 2-16: Estimated Emission Reduction Benefit from Installation of BACT 

for New and Modified Sources......................................................................2-34 

Table 2-17: Emissions Added to Controlled Emissions for Attainment 

Demonstration................................................................................................2-36 
Table of Contents 

v 

LIST OF ACRONYMS 

AQMP Air Quality Management Plan 

CARB California Air Resources Board 

CALTRANS California Department of Transportation 

CAA Federal Clean Air Act 

CAT Catalytic Converters 

CCAA California Clean Air Act 

CEC California Energy Commission 

CO Carbon Monoxide 

DTIM Direct Travel Impact Model 

EDS Emission Data System 

EIS Emissions Inventory System 

U.S.EPA U.S. Environmental Protection Agency 

ERC Emission Reduction Credits 

HD Heavy-Duty 

LDV Light-Duty Vehicles 

MDV Medium-Duty Vehicles 

NCAT Non-Catalytic Converters 

NO2 Nitrogen Dioxide 

NOx Oxides of Nitrogen 

NSR New Source Review 

PM Particulate Matter 

LIST OF ACRONYMS (continued)

PM10 Particulate Matter Less Than 10 Microns In Diameter 
APPENDIX III: Base and Future Year Emission Inventories 

vi 

RECLAIM Regional Clean Air Incentives Market 

SCAG Southern California Association of Governments 

SCAQMD South Coast Air Quality Management District 

SCC Source Classification Code 

SIC Standard Industrial Code 

SOx Oxides of Sulfur 

TOG Total Organic Gases 

UTM Universal Transverse Mercator 

VMT Vehicle Miles Traveled 

VOC Volatile Organic Compounds 
APPENDIX III 

BASE AND FUTURE YEAR EMISSION INVENTORIES

CHAPTER 1 

INVENTORY DEVELOPMENT 

Background 

Air Contaminants 

Inventory Source Category 

Mobile Sources 

Inventory Type 

Chapter 1 Inventory Development 

III-1-1 

INVENTORY DEVELOPMENT 

Background 

To protect the public health and welfare, federal and state standards limit concentration 

levels of air contaminants in ambient air. An emission inventory of air pollutants and 

their sources is essential to identify the major contributors of air contaminants and the 

measures required to reduce air pollution. 1997 is the base year used to project future 

year emissions for the 2003 Air Quality Management Plan (AQMP). The 1997 base 

year emissions inventory reflects adopted air regulations that are implemented as of 

1997; whereas future baseline emissions inventories incorporate adopted rules with post1997 compliance dates and the projected growth factors. A list of SCAQMD rules and 

regulations and their emission reductions is presented in Table 1-1. Table 1-2 lists 

California Air Resources Board (CARB) adopted rules and regulations and their 

associated emission reductions. Both the federal and state Clean Air Acts specify 1990 

as the base year to measure emission reduction progress. In these inventories, only 

anthropogenic sources (i.e., those associated with human activity) are considered. 

Besides 1997, emission levels of air contaminants in the South Coast Air Basin (Basin) 

are compiled for two pre-1997 years (1990, 1995), as well as nine future years (2000, 

2002, 2003, 2005, 2006, 2007, 2008, 2010 and 2020). 

Information necessary to produce an emission inventory for the Basin is obtained from 

the SCAQMD and other governmental agencies including: California Air Resources 

Board (ARB), California Department of Transportation (Caltrans), and Southern 

California Association of Governments (SCAG). 

Each of these agencies is responsible for collecting data (e.g., industry growth factors, 

socio-economic projections, travel activity levels, emission factors, emission speciation 

profile, emissions) and developing methodologies (e.g., model and demographic forecast 

improvements) required to generate a comprehensive emissions inventory. Entire 

statewide emissions inventories are compiled and maintained by CARB in its emission 

related information databases named California Emission Inventory Development and 

Reporting System (CEIDARS), and California Emission Forecasting and Planning 

Inventory System (CEFIS). CARB is the agency responsible for developing the 

emissions inventory for all the mobile sources. CARB provided on-road and off-road 

inventories from their EMFAC2002 and Off-Road Models in the 2003 AQMP. SCAG 

is the primary agency for projecting the growth. Caltrans provides SCAG with 

information regarding highway projects. SCAG incorporates these data into their Travel 

Demand Model for estimating/projecting vehicle miles traveled (VMT) and speed. 

CARB’s on-road inventory also relies on SCAG’s VMT estimates. 
Appendix III: Base and Future Year Emission Inventories 

III-1-2 

Air Contaminants 

Currently, air quality standards exist for the following criteria air contaminants: ozone, 

nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), fine suspended 

particulate less than 10 microns (PM10), lead, and sulfate. This appendix presents 

emission levels in the Basin for the criteria air contaminants and their precursors. 

Specifically, data are included for emissions of total organic gases (TOG), volatile 

organic compounds (VOC), oxides of nitrogen (NOx), oxides of sulfur (SOx), CO, 

particulate matters (PM), PM10 and fine suspended particulate less than 2.5 microns 

(PM2.5). The PM2.5 emissions are presented in this document because the U.S. EPA is in 

the process of adopting PM2.5 air quality standards. Ozone is formed from 

photochemical reactions involving other air contaminants so it is not inventoried. 

Although air quality standards for NOx and SOx are based on NO2 and SO2, respectively, 

emissions of NOx and SOx are in the emissions inventory because multiple species of 

NOx and SOx contribute to the formation of particulate, and NOx and VOC react in the 

presence of sunlight to produce ozone. TOG incorporates all gaseous compounds 

containing the element carbon with the exception of the inorganic compounds, CO,,

carbon dioxide (CO2

), carbonic acid, carbonates and metallic carbides. VOC, a subset of 

TOG, includes all organic gases in TOG except acetone, ethane, methane, methylene 

chloride, methylchloroform, perchloroethylene, methyl acetate, 

parachlorobenzotrifluoride, and a number of Freon-type gases. It should be noted that 

this definition of VOC is different from the one used by the CARB, which includes some 

compounds not considered as U.S. EPA’s VOC. Table 1-3 lists the 19 compounds that 

are exempt in U.S. EPA’s VOC list, but are included in CARB’s ROG. Certain CFC’s 

are still included in the CARB’s VOC list. According to ARB, the total emission 

inventory difference between U.S. EPA VOC and CARB’s ROG is very small. PM 

represents all airborne particulate matters. Important subsets of PM are PM10 and PM2.5. 

In this 2003 AQMP, the amount of VOC in TOG and the amount of PM10 and PM2.5 in 

PM are calculated for each process primarily using species and size fraction profiles 

provided by CARB. Besides average annual day emissions that are reported for all 

criteria pollutants, summer planning inventories (VOC and NOx) are reported for ozone 

purposes and winter planning inventories (CO and NO2) are reported for carbon 

monoxide and nitrogen dioxide purposes. 
Chapter 1 Inventory Development 

III-1-3 

Table 1-1 

Rules and Regulations Adopted by District Since Adoption of 1997/1999 SIPs 

as of October 2002a

Control Measure/Rule 

Title 

SIP 

Commitment 

(tons/day) 

Emission 

Reductions 

Achieved 

Through Rule 

Implementation 

(tons/day) 

Adoption 

Date 

CTS-02C(P2) (Rule 

1171) 

Solvent Cleaning Operations (VOC) 11.0 11.0b 1999 

WST-04 (Rule 1150.1) Disposal of VOC-Containing Materials 

(VOC) 

0.8 0.8 2000 

PRC-3(P2) (Rule 1138) Restaurant Operations (VOC) 0.9 c c 

CTS-020 (Rule 442) Solvent Usage (VOC) 1 1.9 2000 

CTS-02E (Rule 1168) Adhesives (VOC) 1.3 8.3 2000 

RFL-02(P2) (Rule 461) Gasoline Service Stations (VOC) 2 6.2 2000 

CTS-09(P1) (Rule 

1132) 

Large Coating & Solvent Sources – High 

Emitting Spray Booth Facilities (VOC) 

4 5.4 2000 

FUG-06 (Rule 1189) Hydrogen Plants (VOC) 0.8 1.6 2000 

FUG-05(P1) (Rule 

1178) 

Large Fugitive Emissions Sources (VOC) 1 1.7 2001 

PRC-06 (Rule 1131) Industrial Processes - Food Flavoring (VOC) 3 3.0 2001 

CTS-08(P1) (Rule 

1130) 

Industrial Coatings and Solvents (VOC) 2 1.9 2002 

CTS-08(P2) Rule 1122) Solvent Degreasing (VOC) 3 6.2 2001 

CTS-09(P2) (Rule 

1162) 

Polyester Resins (VOC) 3 1.6 2002 

Rule 1102 Dry Cleaners Using Solvent other than 

Perchloroethylene (VOC) 

N/A 0.3 2000 

Rule 1104 Wood Flat Stock Coating Operations (VOC) N/A 0.1 1999 

Rules adopted from October 1996 to September 1999d 79.8 108.1 11/96-

9/99 

 Total VOC 113.6 158.1 
Appendix III: Base and Future Year Emission Inventories 

III-1-4 

Table 1-1 (Continued) 

Rules and Regulations Adopted by District Since Adoption of 1997/1999 SIPs 

as of October 2002a

Control Measure/Rule 

Title 

SIP 

Commitment 

(tons/day) 

Emission 

Reductions 

Achieved 

Through Rule 

Implementation 

(tons/day) 

Adoption 

Date 

CMB-06 (Rule 1121) Control of Nitrogen Oxides from ResidentialType Natural Gas Fired Water Heaters (NOx) 7.6 7.6 1999 

Rule 1146 Emissions of Oxides of Nitrogen from Industrial, 

Institutional, and Commercial Boilers, Steam 

Generators, and Process Heaters (NOx) 

N/A 0.2 2000 

Rules adopted from October 1996 to September 1999d 2.4 4.2 11/96-

9/99 

Total NOx 10 12 

Rule 1158 Storage, Handling, and Transport of Petroleum 

Coke (PM10) 

N/A 1 1999 

Rule 431.2 Sulfur Content of Liquid Fuels (PM10) 

 (SOx) 

N/A 0.1 e

0.4 e

2000 

PRC-3(P1) Rule 1138 Control of Emissions from Restaurant 

Operations (PM10) 

7.0 1 1997 

PRC-01 (Rule 1137) PM10 Emission Reductions from Woodworking 

Operations (PM10) 

7.5f

 7.5 f 2002 

Total 

 PM10 

 SOx 

16.1 9.6 

0.4 

a

 SCAQMD summer planning emission in 2010 (rounded to the nearest whole number), based on 1997 SIP inventory. 

b

 An additional 16 tons of VOC emission reductions associated with Rule 1171 implementation are subject to technology 

assessments in 2003 and 2004 prior to implementation in 2005 and are not included in this value. 

c

 Board approved infeasibility findings in October 2000 and used excess reductions from RFL-02(P2) to meet the SIP 

commitment. 

d

 Reference: Table 1-1 of the 1999 Amendment to the 1997 Ozone SIP for the South Coast Air Basin (SCAQMD, 1999). 

e

 Emission reductions listed include only those from stationary sources. 

f SIP commitment and emission reduction achieved are based on 1997 AQMP inventory methodology. 
Chapter 1 Inventory Development 

III-1-5 

Table 1-2 

Rules and Regulations Adopted by CARB/U.S. EPA Since 1997/1999 SIPs*

RULE TITLE AGENCY VOC NOX ADOPTION 

 DATE** 

Mid-Term Consumer Products I & II CARB 15 0 10/99 

National Heavy-Duty Diesel Standards U.S. EPA 1 11 10/97 

California Heavy-Duty Diesel Veh. Standards CARB 5 44 4/98 

Clean Fuels (Phase 3/Phase 2/Chamber Dep.) CARB 13 12 12/98 

California Large Off-Road Gas/LPG Engine Stds. CARB 16 5 10/98 

National Heavy-Duty Off-Road Diesel Stds. U.S. EPA 6 25 10/98 

Carl Moyer Program CARB 0 3 3/99 

Marine Pleasure Craft Standards CARB/U.S.EPA 24 0 7/01 

Motorcycle Standards CARB 1 0 12/98 

Low Emission Vehicle Program – Phase II CARB 4 43 11/98 

Gas Can Requirements*** CARB 34 0 9/99 

Marine Vessel Standards U.S. EPA 0 2 12/99 

California Heavy-Duty Off-Road Diesel Stds. CARB 4 18 1/00 

Locomotive Standards (incl. MOU-M14)  U.S. EPA 0 17 5/98 

Transit Bus Fleet Rule CARB 0 1 10/02 

Enhanced Vapor Recovery** *** CARB 6 0 3/00 

Medium/Heavy Duty Gasoline Vehicle Stds. CARB 0 1 12/00 

2007 Heavy-Duty Diesel Truck Standards CARB/U.S. EPA 1 16 10/01 

Low-Sulfur Diesel Fuel Req. (enable retrofit) U.S. EPA 0 0 2/01 

National Large Off-Road Gas/LPG Standards U.S. EPA 14 5 9/02 

Small Off-Road Engine Standard Revisions CARB -1 0 3/98 

 Total 143 203 

* SCAQMD summer planning emissions in 2010 (rounded to the nearest whole number), based on 1997 SIP inventory 

** Only latest rule adoption date included. 

*** Portable fuel containers were not included in the 1997/99 AQMP baseline. Emission reductions are from CARB 

rule adoptions Staff Report. 

  Emission reductions from locomotives represent the national emission standards for locomotive engines as well as 

the MOU for the South Coast Air Basin. U.S. EPA has committed to adopt a backstop commitment to ensure that the 

emission reductions associated with the MOU are achieved. The MOU is hereby included as part of the 2003 AQMP 

SIP submittal. A copy of the MOU is available at http://www.arb.ca.gov/msprog/offroad/loc/loco.htm. 

** *** CARB's rule complements District Rule 461. An overall reduction of 6 tons per day of VOC reductions from this 

category is included in the AQMP baseline. 
Appendix III: Base and Future Year Emission Inventories 

III-1-6 

Table 1-3 

List of Compounds Exempt in U.S. EPA’s Definition of VOC; Included in CARB’s 

Definition of ROG

 Compound CAS *

3,3-dichloro-1,1,1,2,2-pentafluoropropane (HCFC-225ca); [ 422-56-0 ] 

1,3-dichloro-1,1,2,2,3-pentafluoropropane (HCFC-225cb); [ 507-55-1 ] 

1,1,1,2,3,4,4,5,5,5-decafluoropentane (HFC-43-10mee); [ 138495-42-8 ] 

 difluoromethane (HFC-32); [ 75-10-5 ] 

 ethylfluoride (HFC-161); [ 353-36-6 ] 

 1,1,1,3,3,3-hexafluoropropane (HFC-236fa); [ 690-39-1 ] 

1,1,2,2,3-pentafluoropropane (HFC-245ca); [ 679-86-7 ] 

1,1,2,3,3-pentafluoropropane (HFC-245ea); [ 24270-66-4 ] 

1,1,1,2,3-pentafluoropropane (HFC-245eb); [ 431-31-2 ] 

1,1,1,3,3-pentafluoropropane (HFC-245fa); [ 460-

73-1 ] 

1,1,1,2,3,3-hexafluoropropane (HFC-236ea); [ 431-63-0 ] 

1,1,1,3,3-pentafluorobutane (HFC-365mfc); [ 406-58-6 ] 

chlorofluoromethane (HCFC-31); [ 593-70-4 ] 

1-chloro-1-fluoroethane (HCFC-151a); [ 1615-75-4 ] 

1,2-dichloro-1,1,2-trifluoroethane (HCFC-123a); [ 354-23-4 ] 

1,1,1,2,2,3,3,4,4-nonafluoro-4-methoxy-butane (C4F9OCH3); [ 163702-07-6 ] 

2-(difluoromethoxymethyl)-1,1,1,2,3,3,3-heptafluoropropane ( (CF3)2CFCF2OCH3); [ 163702-08-7 ] 

1-ethoxy-1,1,2,2,3,3,4,4,4-nonafluorobutane (C4F9OC2H5); [ 163702-05-4 ] 

2-(ethoxydifluoromethyl)-1,1,1,2,3,3,3-heptafluoropropane ( (CF3)2CFCF2OC2H5); [ 163702-06-5 ] 

* Note: Chemical Abstract Service (CAS) identification numbers have been included in brackets [ ] for convenience. 
Chapter 1 Inventory Development 

III-1-7 

Inventory Source Category 

Stationary Sources

Stationary sources of emissions are grouped into two categories. They are point sources 

and area sources. Point source emissions are from facilities having one or more pieces 

of equipment registered and permitted with SCAQMD. Therefore, SCAQMD is able to 

collect facility emission related information. Area source emissions are from numerous 

small facilities or pieces of equipment, such as gasoline-dispensing facilities, residential 

water heaters, consumer products and architectural coatings, for which locations are not 

specifically identified. For modeling purposes, area source emissions are spatially 

allocated to grid cells using demographic data (e.g., population, housing, and land use). 

Point Sources

The 1997 point source emissions inventory is based on the emissions data reported by 

point source facilities in the 1996/97 Annual Emissions Reporting (AER) Program. This 

program applies to facilities emitting 4 tons or more of VOC, NOx, SOx, or PM or 

emitting more than 100 tons of CO per year, as specified in Rule 301(e) which are 

required to pay emission fees. Facilities subject to the AER Program calculate and report 

their emissions primarily based on their throughput data (e.g., fuel usage, material 

usage), appropriate emission factors, and control efficiency (if applicable). Under the 

1996/97 AER Program, approximately, 3200 facilities reported their annual emissions to 

SCAQMD. Emissions from smaller industrial facilities not subject to the AER Program, 

which represent a small fraction of the overall inventory, are included as part of the area 

source inventory. 

 In order to prepare the point source inventory, emissions data for each facility were 

categorized based on EPA’s Source Classification Codes (SCCs) for each emission 

source category. Since the AER Program collects emissions data on an aggregate basis 

(i.e., equipment and processes with same emission factor are grouped and reported 

together), facility’s permitted equipment data were used in conjunction with the reported 

data to assign the appropriate SCC codes and develop the inventory at SCC level. For 

modeling purpose, facility location is specified in Universal Transverse Mercator (UTM) 

coordinates. Business operation activity profile is also recorded. For growth purpose, 

facility business type is designated by Standard Industrial Code (SIC). 
Appendix III: Base and Future Year Emission Inventories 

III-1-8 

Area Sources

SCAQMD and CARB shared the responsibility for developing the 1997 area source 

emissions inventory for approximately 350 area source categories. Specifically, 

SCAQMD developed the area source inventory for about 90 categories whereas CARB 

developed the remaining area source categories (of which 230 categories were 

associated with consumer products, architectural coatings, and degreasing). For each 

area source category, a specific methodology is used for estimating emissions. In the 

1997 area source inventory, a number of existing methodologies were used with updated 

activity data such as fuel data or sales data (e.g., fuel combustion categories, landfills, 

oil/gas production); new methodologies were developed for several categories (e.g., 

agricultural pumps, residential wood combustion); three new categories (i.e., 

composting, cargo tanks and gas cans) were added to the inventory, and other existing 

methodologies were refined based on more recent studies (e.g., consumer products, 

architectural coatings). 

Comparison of 1993 and 1997 inventories 

Figure 1-1 and 1-2 provide a comparison of the 1993 in the 1997 AQMP and 1997 point and 

area source inventories for all pollutants. 
Chapter 1 Inventory Development 

III-1-9 

94

84

94

79

22 24

14 12

0

20

40

60

80

100

T

o

n

s

P

e

r

D

a

y

VOC NOx SOx PM10

1993

1997

FIGURE 1-1 

Total Point Source Emissions 

357

333

60 53

1 1

366

228

0

50

100

150

200

250

300

350

400

T

o

n

s

P

e

r

D

a

y

VOC NOx SOx PM10

1993

1997

FIGURE 1-2 

Total Area Source Emissions 
Appendix III: Base and Future Year Emission Inventories 

III-1-10 

Changes in Point Sources 

The point source inventory (except SOx) continued its downward trend primarily due to the 

implementation of existing stationary source regulations. As indicated in Figure 1-1 above, 

the 1993 VOC and NOx emissions decreased from 94 and 94 tons per day to 84 and 79 tons 

per day respectively in 1997. In addition to the effect of existing regulations, another major 

reason for the decreased VOC emissions was the use of EPA’s correlation equations for 

calculating fugitive emissions (i.e., component leaks) by the petroleum industry, which 

significantly reduced the calculated fugitive emissions. 

Also, VOC emissions (primarily methanol) from hydrogen plants process vents in refineries 

were identified for the first time in 1997, which were included in the baseline inventory. 

This new emission source category contributed to about two tons of VOC emissions per day 

in 1997 and is currently regulated under SCAQMD Rule 1189. For NOx emissions, the 

majority of the emission decrease in 1997 (compared to 1993) is attributed to reductions 

achieved through the RECLAIM Program. The increase in SOx emissions was primarily due 

to changes in methodology for estimating emissions from refinery flares. The decrease in 

PM10 was primarily due to implementation of several BACM rules (e.g., Rule 403 and Rule 

1186). 

Changes in Area Sources 

The area source inventory also decreased between 1993 and 1997 for all criteria pollutants 

due to the effect of rules adopted by SCAQMD and CARB as well as due to the improved or 

updated area source methodologies used for estimating emissions, which are briefly 

discussed below. 

Rule Implementation 

The 1998 Architectural and Industrial Maintenance Coatings Survey conducted by CARB 

indicated an increase in the use of water-based coatings compared to oil-based coatings 

between 1990 and 1996 (76% to 82%), primarily due to the SCAQMD Rule 1113 – 

Architectural Coatings. As a result, VOC emissions decreased by 5 tons per day in 1997 

compared to 1993. 

In addition, a number of other rules which had implementation dates between 1993 and 1997 

contributed to some of the emission reductions between these years. Emission source 

categories mostly affected by rules included: adhesive applications (Rule 1168), commercial 

bakery ovens (Rule 1153), screen printing operations (Rule 1130.1), solvent cleaning 

operations (Rule 1171), marine tank vessel operations (Rule 1142), sumps and wastewater 

separators (Rule 1176), organic liquid loading (Rule 462), gasoline transfer and dispensing 
Chapter 1 Inventory Development 

III-1-11 

(R461), stationary internal combustion engines (Rule 1110.2), sulfur content of gaseous fuels 

(Rule 431.1), and consumer products regulated by CARB. 

Improved/Updated Methodologies 

Gasoline Dispensing - Emissions from gasoline dispensing were adjusted to account for the 

low levels of compliance identified in various audits conducted by SCAQMD since 1997 

and tests conducted by CARB in 1999. The audits and tests revealed that the overall vapor 

recovery effectiveness at gasoline dispensing facilities was significantly reduced as a result 

of many defects found in the systems. The adjustment caused an increase of the emissions 

for this category from 23 tons per day in 1993 to 35 tons per day in 1997. 

 

Industrial Coatings - A more detailed evaluation of the unspecified industrial coatings 

category revealed that emissions from this category were previously over-estimated and were 

primarily attributed to more specific coating categories. Accordingly, the emissions from 

this category were distributed to appropriate categories. 

Consumer Products - A comprehensive survey of consumer products and aerosol coatings 

was conducted by CARB in 1997 which identified a number of new product categories not 

inventoried before and also provided a more accurate basis for estimating emissions from 

existing categories. Between 1993 and 1997, emissions from this category were also 

reduced due to CARB’s consumer products regulation. The net effect of the survey results 

and CARB’s regulation was an overall increase in VOC emissions from 105 to 118 tons of 

VOC per day. 

Residential Wood Combustion - For the residential wood combustion category (fireplaces), 

AQMD used a new methodology which relied on the total number of wood burning 

households in each county (based on survey results), the estimated amount of wood burned, 

and AP-42 emission factors. The new methodology increased the PM and CO emissions 

from 0.4 and 6 tons per day in 1993 to 4 and 28 tons per day in 1997 respectively. CARB is 

currently evaluating other methodologies and is also conducting a survey to develop a better 

estimate of emissions from this category. 

Composting - As part of the overall ammonia emissions inventory update, emissions from 

composting operations were quantified for the first time. VOC emissions from composting 

were estimated at 6.8 tons/day. (Ammonia emissions are discussed in the Special Studies 

section below.) 

Truck Stops - This is the first time that idle emissions from truck stops have been included 

in the inventory. Truck stops emissions were estimated from survey data from IdleAire 

Technologies Corp. conducted in 2001 and emission rates provided by CARB. There are 

approximately 1,700 truck stop spaces in the SCAB, located in Fontana, Ontario, Banning, 
Appendix III: Base and Future Year Emission Inventories 

III-1-12 

Colton, Rialto, Vernon and Wilmington. Part of the truck stop emissions are counted in 

CARB’s EMFAC2002. CARB collected truck stop data from in-state trucks and grouped 

them into idle emissions with the other truck idling activities, such as idling at distribution 

centers, idling for loading and unloading, and in-trip idling. CARB will expand and 

complete their truck stop emission data in their next generation of on-road mobile source 

emission factors. The overlapping part of the truck stop emissions in the EMFAC2002 has 

been eliminated. The estimated 2010 annual average day emissions are 0.14 tons and 2.52 

tons for VOC and NOx respectively. 

Metrolink - Commuter train emissions were never estimated in the inventory and are now 

grouped under the Trains category. Southern California Regional Rail Authority provided 

the total train miles, train travel time, average speed and engine specifications. CARB 

provided the emission rates and EPA’s passenger locomotive driving cycles for emission 

estimates. The estimated 2010 annual average week day emissions are 0.11 tons, 2.95 tons 

and 0.35 tons for VOC, NOx and SOx respectively. 

Fugitive Dust - Subsequent to the approval of the 1997 AQMP, CARB released updated 

emission factors for several fugitive dust sources. The 2003 AQMP incorporates those 

updated emission factors and / or 1997 activity data for source categories such as entrained 

paved and unpaved road dust, construction, windblown dust, and farming operations. The 

greatest change was in the estimation of windblown agricultural dust; new emission factors 

dramatically reduced annual emission estimates. (Windblown dust can still be a major 

contributor during high wind episodes). Better road construction activity data have become 

available with the release of SCAG’s 2001 RTP, resulting in revised road construction 

emissions. Although VMT increased slightly in 1997, entrained paved road dust emission 

estimates are smaller in the 2003 AQMP due to lower CARB emission factor. Entrained 

road dust remains the major source of fugitive primary PM10 emissions. Overall emission 

estimates were lower for the 2003 AQMP. Table 1-4 indicates the changes in PM10

(tons/day) to the fugitive dust inventories. 
Chapter 1 Inventory Development 

III-1-13 

Table 1-4 

Comparison of 1993 and 1997 Major PM10 Sources Emissions (Tons/Day) 

Source Category 1997 AQMP 2003 AQMP 

 1993 Inventory 1997 Inventory

Paved Road Dust 168.9 134.3 

Unpaved Road Dust 52.4 13.0 

Construction 44.3 29.6 

Windblown 54.2 19.2 

Farming Operations 15.7 7.4 

Landfills 1.0 0.2 

Total 336.5 203.7 

Special Studies 

Aircraft – In 1999, an inventory study was conducted by Energy and Environmental 

Analysis for SCAQMD to develop the 1997 aircraft emissions for commercial, general 

aviation (GA), and military airports. The aircraft activity data (i.e., number of aircraft 

operations by aircraft types) was obtained from commercial airport operators, and from FAA 

for general aviation airports. The U.S. EPA’s Emissions Dispersion Modeling System 

(EDMS) was used in this study to calculate aircraft emissions. Emissions from commercial 

aircraft were calculated based on the aircraft type, engine type, number of engines, time-inmode, emission factors, mixing height, and the number of landing and take-off cycles. GA 

aircraft emissions were primarily calculated using AP-42 emission factors. Military airport 

emissions were provided by military airport operators. For future years, SCAG’s 2025 

projected emission inventories for commercial airports and growth factors for GA airports 

were utilized. For intermediate years, emissions for commercial airports were interpolated 

between 1999 and 2025 based on the passenger level (i.e., million air passengers) specified 

for each commercial airport in the 2001 Regional Transportation Plan. 

Marine Vessels – The Marine Vessels Emissions Inventory study was conducted in 1999 by 

Arcadis, Geraghty and Miller (previously known as Acurex Environmental) for SCAQMD to 

update the 1997, 2000, 2010, and 2020 baseline emissions inventory. The Study included 

ocean-going vessels (calling on San Pedro Bay Ports of Los Angeles and Long Beach or on 

the Chevron offshore facility at El Segundo, as well as ships transiting through the area 

without calling on the ports), tugboats, harbor vessels, fishing vessels, and U.S. Navy and 

coast Guard Vessels. Emissions for ocean-going vessels (i.e., tankers, container ships, 

passenger ships) were calculated based on the activity data including the number of ships 

calling on the ports, propulsion type (motor ship, steamship), engine size, service speed, 
Appendix III: Base and Future Year Emission Inventories 

III-1-14 

time-in-mode (hotelling, maneuvering and cruising), power requirement for each mode, and 

the available emission factors for different engine types. Emissions from other marine vessel 

categories were primarily calculated based on the number of vessels, fuel consumption rate, 

and appropriate emission factors. 

Ammonia Sources - A comprehensive revision to the ammonia inventory was performed by 

AVES(ATC) as part of the Technical Enhance Program 2000 (TEP2000) program. The final 

report was released in August 2001 and entitled “1997 Gridded Ammonia Emission 

Inventory Update for the South Coast Air Basin.” This revision systematically updated 

emission factors and activity levels (e.g. population) for Basin ammonia sources. The 

inventory now includes composting emissions, a previously uninventoried source. Based on 

recent tunnel studies, including Fraiser and Cass (1998), AVES recommends that the mobile 

source emission factor is 3 to 4 times greater than previously estimated. This change 

dramatically changes the amount of mobile source ammonia emissions, but these emissions 

continue to be spread out spatially. However, until federal and state agencies review and 

confirm the new emission factor, AQMD staff will continue to use the current lower 

emission factor in its PM modeling. The AVES inventory also shows fewer emissions from 

poultry (lower emission factor) and horses (smaller population estimate and emission factor), 

and higher emissions from dairy cows (higher emission factor and inclusion of heifers and 

calves) than the 1997 AQMP inventory. Table 1-5 summarizes the changes to the ammonia 

inventory. 

Table 1-5 

Changes in Ammonia Emissions (Tons/Day) between 1995 and 1997 

Source Category 1997 AQMP 2003 AQMP 

 1995 Inventory 1997 Inventory 

Soil / Fertilizer 50.0 41.9 

Domestic 9.1 25.9 

Point / Other 3.1 13.2 

Cattle 10.8 32.4 

Poultry 28.8 22.6 

Other Livestock 17.0 5.4 

Composting / Related Operations NI 8.7 

Mobile Source 7.0 7 

Total 155.8 157.1 
Chapter 1 Inventory Development 

III-1-15 

Mobile Sources

On-Road Mobile Sources 

Caltrans, CARB, SCAG, and the Department of Motor Vehicles (DMV) supply data 

necessary to develop the on-road mobile source inventory. DMV maintains a count of 

registered vehicles; and Caltrans provides highway network, traffic counts and road 

capacity data. SCAG maintains the regional transportation model containing the 

temporal and spatial distribution of motor vehicle activity (travel time, travel speed, and 

volume of traffic for morning-peak, afternoon-peak, mid-day and night hours). In 

addition, SCAG periodically conducts origin and destination surveys to validate the 

regional transportation model, and updates a demographic database for population, 

housing, employment and patterns of land use within SCAQMD jurisdiction. 

CARB estimates on-road motor vehicle emissions from their emissions model called 

EMFAC. Emission rate data are collected from various sources, such as individual 

vehicles in a laboratory setting, tunnel studies and certification data, etc. Vehicle 

activity data are obtained from regional planning agencies, such as SCAG. The EMFAC 

model calculates exhaust and evaporative emission rates by vehicle type for different 

temperatures, operating speeds and relative humidity. Temperature and humidity 

profiles are used to produce month specific, annual average; seasonal and episodic 

inventories. Parameters accounted for by EMFAC include the following: type of control 

technology and fuel usage, distribution of operating speeds, speed and temperature 

correction factors, and the reduction in emissions resulting from the state’s motor vehicle 

regulatory programs. CARB released the latest emissions model (EMFAC2002) in 

September, 2002 to be used for the development of the motor vehicle emissions 

inventory. EMFAC2002 includes (1) thirteen vehicle classes (light-duty passenger, 

light-duty trucks under 3750 pounds, light-duty trucks between 3750 pounds and 5750 

pounds, medium-duty trucks, light-heavy-duty trucks between 8501 pounds and 10000 

pounds, light-heavy-duty trucks between 10000 pounds and 14000 pounds, mediumheavy-duty trucks, heavy-heavy-duty-trucks, line-haul, urban buses, motorcycles, school 

buses and motor homes.); (2) two fuel types (gas and diesel); (3) three technology 

groups (catalyst, non-catalyst, and diesel); (4) 60 calendar years (1980-2040); (5) two 

exhaust processes (starts and running); (6) four evaporative processes (diurnal, hot soak, 

running loss, and resting loss); (7) seven pollutants (HC, CO, CO2, NOX, PM, SOX, lead) 

and (8) fuel consumption. EMFAC2002 also includes a “What-If-Scenario Generator” 

(WIS) that can be used to evaluate the impacts that changes to various inputs, such as 

population, vehicle speed or control strategy, would have on motor vehicle emissions. 

In the Final AQMP, SCAG’s updated activity data were incorporated into EMFAC2002 

model to estimate the on-road emission inventories.

For modeling gridded inventory, emissions from on-road motor vehicles are estimated at 

grid level, by using Caltrans’ Direct Travel Impact Model (DTIM). DTIM calculates 

emissions based on detailed information regarding each link (roadway segment) in an 
Appendix III: Base and Future Year Emission Inventories 

III-1-16 

area for each hour of the day. The required inputs of the model include traffic volume, 

traffic speed, vehicle fleet characteristics, and ambient temperature. The characteristics 

of DTIM include: (1) It calculates emissions based on more specific information, such as 

link speed, link volume, and temperature; (2) It takes into consideration the spatial and 

temporal distribution of emissions, thus providing hourly gridded emissions; and (3) It 

can show the emission impact on various types of transportation and regional planning 

alternatives (e.g., changes in roadway network configuration, or public transportation 

services). DTIM system consists of three steps. First step is to reformat and sort 

emission rates for all vehicle classes produced by the CARB vehicle emission factor 

program (EMFAC). Second step is to produce average emission rates for specific 

vehicle classes identified by the user. The last step is to combine emission rates with 

vehicle activity estimates from a transportation demand model and supplemental 

information on temperatures and temporal patterns to produce regional mobile source 

emissions and hourly gridded mobile emissions. DTIM provides the detailed emission 

inputs needed by photochemical grid models such as Urban Airshed Model (UAM). 

DTIM4 has been recently updated to incorporate CARB’s EMFAC2002. 

CARB’s EMFAC7G model was used in the 1997 AQMP. EMFAC 2002 model is used 

in this 2003 AQMP. Between these two models, CARB released two other EMFAC 

models; they are EMFAC2001 version 2.02 and EMFAC2001 version 2.08. Major 

improvements from EMFAC7G to EMFAC2002, other than updated all the existing 

factors from the most current adopted rules and available data and items mentioned 

previously (thirteen vehicle classes, two exhaust processes, four evaporative processes, 

sixty calendar years....,etc.), include updated unregistered vehicle estimates; updated 

Inspection/Maintenance benefit estimates; updated idle emission rates; extended idle for 

heavy-duty trucks; adding EVII and Tier II programs; and adding air conditioning 

correction factors. A detailed description of EMFAC2002 is available at CARB’s 

website. (www.arb.ca.gov/msei/msei.htm) EMFAC2002 results indicate that 

EMFAC7G underestimated the emissions. Figure 1-3 provides a comparison of the 

1997 on-road annual average emissions (tons/day) by pollutant between EMFAC7G and 

EMFAC2002. It should be noted that in addition to methodology improvements, 

EMFAC2002 also incorporates rules adopted since the release of EMFAC7G. 

The on-road planning and annual average inventories in this Appendix are based on 

CARB’s EMFAC2002 inventories, while DTIM is used to develop modeling inventory. 

EMFAC2002 has been approved by the U. S. EPA for use as a SIP motor vehicle 

emissions model, and for use in analyzing conformity against emission budgets. 

Accordingly, EMFAC2002 will be the basis for on-road planning inventories, emission 

budgets, and rate-of-progress calculations. 
Chapter 1 Inventory Development 

III-1-17 

FIGURE 1-3 

Comparison of 1997 and 2010 Baseline Emissions Between 1997 AQMP (EMFAC7G) and 

2003 AQMP (EMFAC2002) 

Off-Road Mobile Sources 

All mobile sources not included in the on-road mobile source inventory are considered 

as “off-road” mobile sources which include aircraft, ships, commercial boats, 

recreational vehicles, construction equipment, etc. This is the first time CARB’s OFFROAD model is used to estimate off-road emissions in the AQMP. This model 

calculates emissions from more than one hundred equipment types. “OFF-ROAD” 

model incorporates various aspects of off-road elements, such as the effects of various 

adopted regulations, technology types, and seasonal conditions on emissions. The model 

combines population, activity, horsepower, load factors, emission factors and control 

factors to yield the annual equipment emissions by county, air basin or state. The spatial 

165

443

212

519

0

100

200

300

400

500

600

1997 2010

VOC

Tons/Day

365

606

434

761

0

100

200

300

400

500

600

700

800

900

1000

1997 2010

NOx

Tons/Day

14

20 21

19

0

5

10

15

20

25

1997 2010

PM10

Tons/Day

1809

3625

2048

5092

0

1000

2000

3000

4000

5000

6000

1997 2010

CO

Tons/Day

1997 AQMP 2003 AQMP
Appendix III: Base and Future Year Emission Inventories 

III-1-18 

and temporal features have also been incorporated to estimate the seasonal emissions. 

The improvements from the “OFF-ROAD” model versus the methodology used before 

include: (1) More equipment types, horsepower groups and fuel types are categorized; 

(2) Average maximum horsepower, load factor and usage estimates are updated based on 

recent available data. (3) Equipment population in any given calendar year is distributed 

by age; (4) All the adopted regulations related to emission reductions are reflected in the 

emission calculations. These features make the OFF-ROAD model more accurate in its 

depiction of emissions. Off-road emissions can be found at CARB’s website. 

(www.arb.ca.gov/msei/off-road/off-road.htm) Currently other than ships, aircraft, 

locomotive and recreational vehicles, all the other categories are being estimated from 

the OFF-ROAD model. CARB’s updated population and activity data in lawn and 

garden and locomotive categories were used in the 2003 AQMP. Continuous effort is 

being made to improve the off-road mobile source emissions. Figure 1-4 illustrates the 

comparison of emissions presented in the 1997 AQMP and 2003 AQMP. 
Chapter 1 Inventory Development 

III-1-19 

FIGURE 1-4 

Comparison of Off-Road Baseline Emissions 

1997 AQMP and 2003 AQMP (off-road model) 

(Annual Average Emissions) 

112 119 123

237

0

50

100

150

200

250

300

1997 2010

VOC

Tons/Day

228

251 257

312

0

50

100

150

200

250

300

350

400

1997 2010

NOx

Tons/Day

1335 1248

1094

1410

0

200

400

600

800

1000

1200

1400

1600

1997 2010

CO

Tons/Day

16

14

19

21

0

5

10

15

20

25

1997 2010

PM10

Tons/Day

1997 AQMP 2003 AQMP
Appendix III: Base and Future Year Emission Inventories 

III-1-20 

Inventory Type 

Average Annual Day Inventory

The average annual day emissions inventory was derived primarily by dividing the 

annual total emissions by 365, except for the emissions derived from CARB’s 

EMFAC2002 (on-road mobile sources) and OFFROAD (most off-road mobile sources) 

models. For those sources, the average annual day emissions represent 40% of winter 

emissions and 60% of the summer emissions. In addition, the average annual day 

inventory was developed for all criteria pollutants regardless of their attainment status. 

The average annual day emissions are used to estimate cost-effectiveness of proposed 

control measures and future tracking of AQMP implementation (e.g., annual progress 

report on rule adoption). 

Planning Inventory

The challenge of bringing the Basin air quality into compliance with state and federal air 

quality standards is complicated by the fact that ambient concentrations of ozone are 

typically at their highest during the summer (defined as May through October for 

planning purposes) while those for CO and NO2 are generally highest during the winter 

months (November through April). Any strategy designed to mitigate air pollution in 

the Basin must consider this seasonal variation in ambient air quality. Planning 

inventories are also referred to as seasonal inventories. These inventories only present 

emissions for those air pollutants or their precursors for which the area is in nonattainment with state or federal air quality standards. The intent of a planning inventory 

is to characterize emission levels representative of those that occur during the typical 

season of violations. For example, the summer, or ozone, planning inventory contains 

emissions of ozone precursors (i.e. VOC and NOx) during the summertime. The winter, 

CO and NO2, planning inventory represent emission levels during the wintertime. These 

planning inventories provide the basis for tracking emission reduction progress specified 

by the federal Clean Air Act (CAA) and California Clean Air Act (CCAA). The CAA 

requires the District to produce a plan for reducing all non-attainment pollutants or their 

precursors by fifteen percent between 1990 and 1996, and three percent each year 

thereafter, averaged every consecutive three years until reaching the attainment date. 

The CCAA requires emission reductions by five percent or more per year, averaged 

every three consecutive years until 2000. In addition, the CAA specifies 1990 as the 

base year, whereas the CCAA specifies 1987. 

CARB has developed guidelines for the development of planning inventories. For point 

sources emission estimates represent an “average annual operating day.” Emissions 

from point sources are calculated by dividing the total annual emissions produced by a 

source by the number of days the source was in operation. For example, if a company 

emitted 150 tons in a year and the production lines operated 5 days a week for 40 weeks, 

then the average operating emissions from this facility are calculated to be 150 tons 

divided by 200 days or 0.75 tons per day. Although emissions of volatile organic 
Chapter 1 Inventory Development 

III-1-21 

compounds (VOC) from some sources may depend on the ambient temperature or other 

meteorological factors, adjustments are not currently made for these parameters. 

However, CARB staff is continuing to evaluate possible adjustments. 

For area and other mobile sources, planning emissions represent an “average seasonal 

operating day.” As an example, VOC emissions produced by asphalt road-paving 

operations are calculated by taking into account the variation in monthly levels and 

weekly operating days for paving activity during the year. Road paving varies from 

maximum rates during the summer season to minimum levels during the winter season. 

Paving activity varies throughout the week with, on average, five operating days in a 

week. The allocation of annual area source emissions among the seasons is based on 

estimated relative monthly and weekly emissions patterns. As pointed out earlier, 

sources included in CARB’s OFF-ROAD model do include seasonal activity and 

temperature profiles which are used to develop the planning inventories. 

Both summer and winter planning on-road emission inventories were provided by 

CARB by incorporating SCAG’s updated activity data into CARB’s EMFAC2002. 
CHAPTER 2 

SUMMARIES OF EMISSIONS 

Baseline Emissions Inventories 

Base Year Emission Data 

Future Year Emission Data 

Emission Trend Analysis 

Growth Impact 

Controlled Emissions Inventories 

Emission Impacts of SCAQMD Programs 

Proposed Control Measures 

CEPA Emission Calculations 

CARB Emission Date Report System 
Chapter 2 Summaries of Emissions 

III-2-1 

BASELINE EMISSIONS INVENTORIES 

Base Year Emission Data 

The 1997 emission inventory is used as the base year inventory to project future year 

emissions. It represents the most recent and comprehensive inventory development. For 

the purposes of Reasonable Further Progress (RFP) reporting as required by both the 

federal and state CAAs, 1990 emissions were reconstructed. 1990 emissions were 

reconstructed or backcast from 1997 using the latest inventory methodologies (e.g., 

EMFAC2002 and OFF-ROAD) and socioeconomic/demographic data for all source 

categories, except for the point sources where reported emissions by facilities were used. 

Attachments A, B and C include emissions for 1995, 1997, 2000, 2002, 2003, 2005, 

2006, 2007, 2008, 2010, and 2020 by major source categories. A major source category 

refers to a group of emission sources with similar characteristics. Emissions result 

primarily from the combustion of fuels, evaporation of solvents or fuels, and processing 

of materials. Hence, stationary sources are grouped under fuel combustion; waste 

disposal; cleaning and surface coatings; petroleum production and marketing; industrial 

processes; solvent evaporation; and other miscellaneous processes. Mobile sources are 

divided into two source categories: 1) on-road, and 2) other (off-road) mobile sources. 

On-road mobile sources include light-duty passenger vehicles; light-, medium-, and 

heavy- heavy duty trucks; motorcycles; urban buses; school buses and motor homes. 

Other mobile sources include aircraft; trains; ships and commercial boats; off-road 

recreational vehicles; off-road equipment; farm equipment, fuel storage and handling 

and truck stops. Attachment A summarizes annual average day baseline inventories at 

major source category. Attachment B is for summer planning baseline inventories and 

Attachment C is for winter planning inventory. Attachment D lists top 300 VOC and 

NOx polluters (facilities) in the 1997 inventory in the SCAB. Attachment E illustrates 

on-road emissions by vehicle class for 1990, 1997, 2006, 2010, and 2020. Due to the 

recent significance placed on diesel emissions, Attachment F has been added, showing 

various source categories’ emissions due to combustion of diesel fuel. Figure 2-1 

compares the annual average emissions between 1990 and 1997. All pollutants have 

been significantly reduced between these two years. The adopted air rules and 

regulations are the major contributors toward the reductions. 
Appendix III Base and Future Year Emission Inventories 

III-2-2 

FIGURE 2-1 

Comparison of Annual Average Emissions Inventory of 1990 and 1997 

1,172

1,780

0

500

1000

1500

2000

1990 1997 VOC Emissions

Tons/Day

1,204

1,592

0

500

1000

1500

2000

1990 1997 NOx Emissions

Tons/Day

6,653

10,589

0

1500

3000

4500

6000

7500

9000

10500

12000

13500

1990 1997 CO Emissions

Tons/Day

58

98

0

40

80

120

1990 1997 SOx Emissions

Tons/Day

279

339

0

150

300

450

600

1990 1997 PM10 Emissions

Tons/Day

Point Area On-Road Off-Road 
Chapter 2 Summaries of Emissions 

III-2-3 

FUTURE YEAR EMISSIONS 

Future baseline emissions, which are those expected if no additional air quality 

regulations are introduced, are given in this appendix for the years 2000, 2002, 2003, 

2005, 2006, 2007, 2008, 2010, and 2020. These emissions are forecast from the 1997 

base year by incorporating the controls implemented under SCAQMD and CARB rules 

adopted as of October 31, 2002 and a specific set of growth rates from SCAG for 

population, industry, and motor vehicle activity. Growth projections from SCAG were 

replaced for certain categories where more specific information is available to improve 

emission forecasts. For example, California Energy Commission’s (CEC) energy 

demand forecasts for natural gas and petroleum refineries are used to forecast the 

emissions of those source categories. Rules adopted after October 31, 2002 are treated 

as control measures for emission reduction accounting purposes. The impact of New 

Source Review and emissions budgeted for several District programs are addressed in 

the Controlled Emission Data section. Due to the adoption of the Regional Clean Air 

Incentive Market (RECLAIM) program in October 1993, emissions are divided into two 

categories, RECLAIM and non-RECLAIM. Future emissions from RECLAIM sources 

are estimated based on their allocations specified by District Rule 2002 as well as the 

trading activity as of 2001. The methodology used to forecast emissions for nonRECLAIM sources is described in the following sections. Baseline emissions for future 

years are obtained using the following equation: 

(F.Y.)i

 = (B.Y.)i(C.F.)i(G.F.)i

where (F.Y.)i is the forecast emissions of an air pollutant in the South Coast Air Basin 

for a future year. (B.Y.)i refers to the base year emissions of the air pollutant (i.e., 

1997). The control factor, (C.F.)i, is an indicator of the level of control imposed on a 

specific source category as a result of adopted state and local air quality regulations. 

(G.F.)i is a growth factor determined for different categories of industry and 

socioeconomic data. 

Control Factors

Air pollution regulations adopted or amended by the District and CARB prior to October 

31, 2002 with compliance dates after 1997 are listed in Tables 2-1 and 1-2, respectively. 

The impact of these rules is included in the baseline emission forecasts by means of 

control factors. Control factors were developed in reference to 1997 and applied to 

source categories and/or specific industries affected by the adopted rules/amendments. 

For industry, the standard industrial codes (SIC) system is used, and for equipment, 

EPA’s SCC system is used. A control factor (C.F.)i is calculated by the following 

equation for an individual source category: 

(C.F.)i= 1 - Control Efficiency 
Appendix III Base and Future Year Emission Inventories 

III-2-4 

Control efficiency is mostly based on estimates projected during rulemaking. Control 

factors represent the remaining emissions after a rule or regulation is implemented after 

1997. Table 2-2 lists control factors for the years 2000 and 2010 for District rules with 

post-1997 compliance dates. 

 Growth Factors

Growth factors applied to each emission inventory source category were derived from 

several surrogates, including industry output growth, employment growth, demographic 

growth and others. These growth projections were developed primarily by SCAG. The 

selection of surrogate by which emission growth is projected dependent on the type of 

activity. In general, manufacturing sectors and solvent groups use output growth as a 

surrogate. Output growth is the product of projected employment and productivity. For 

industry with finish products employment growth appears to be a better indicator than 

output growth, such as agricultural sector, construction business, etc. Certain emission 

sources use demographic data as surrogate, such as architectural coatings and landfills. 

In some cases modifications to the traditional forecasting methodology are warranted in 

order to better project future emissions. For example, ships and aircraft emissions are 

provided via special studies. An inventory study was conducted by Energy and 

Environmental Analysis to develop the 1997 aircraft emissions. The marine vessels 

emissions inventory was conducted in 1999 by Arcadis, Geraghty and Miller to update 

the 1997, 2000, 2010 and 2020 baseline emissions. Table 2-3 lists the types of growth 

surrogates used for the inventory source categories in the 2003 AQMP. 
Chapter 2 Summaries of Emissions 

III-2-5 

Table 2-1 

Rules and Regulations Adopted/Amended by SCAQMD 

between September 30, 1996 and October 31, 2002 * 

Rule 

Number 

Title Adoption/ 

Amendment Date 

403 Fugitive Dust 12/98 

431.1 Sulfur Content of Gasoline Fuels 6/98 

431.2 Sulfur Content of Liquid Fuels 9/00 

442 Usage of Solvents 12/00 

461 Gasoline Transfer and Dispensing 6/01 

462 Organic Liquid Loading 5/99 

1102 Dry Cleaners Using Solvents Other Than Perc 11/00 

1104 Wood Flat Stock Coating Operations 8/99 

1107 Coating of Metal Parts and Products 11/01 

1110.1 Stationary Internal Combustion Engines 11/97 

1110.2 Gaseous- and Liquid-Fueled Internal Combustion 11/97 

1113 Architectural Coatings 7/01 

1121 Residential Natural Gas-Fired Water Heaters 12/99 

1122 Solvent Degreasers 7/01 

1124 Aerospace Assembly and Component Mfg. Op. 9/01 

1130 Graphic Arts 10/99 

1130.1 Screen Printing Operations 12/96 

1131 Food Product Manufacturing and Processing 9/00 

1132 High Emitting Spray Booth Facilities 1/01 

1136 Wood Products Coatings 6/96 

1137 PM10 Emissions from Woodworking Op. 2/02 

1138 Restaurant Operations 11/97 

1145 Plastic, Rubber and Glass Coatings 2/97 

1146 Non-Residential Boilers, Steam Generator, PH 11/00 

1146.2 Large Water Heaters and Small Boilers 1/98 

1158 Storage, Handling, Transport of Petroleum Coke 6/99 

1162 Polyester Resin Operations 11/01 

1168 Adhesive and Sealant Applications 7/02 

1171 Solvent Cleaning Operations 8/02 

1176 Sumps and Wastewater Separators 9/96 

1178 Storage Tanks at Petroleum Facilities 12/01 

1186 Paved and Unpaved Roads and Livestock Op. 9/99 

1189 Hydrogen Plant Process Vents 1/00 

2202 On Road MV Mitigation 10/98 

* Only the latest rule amendment dates with emission reductions are listed. 
Appendix III Base and Future Year Emission Inventories 

III-2-6 

 Table 2-2 

Control Factors by District Rules with Post-1997 Compliance Dates * 

RULE 2000 2010 

Number Rule Name VOC NOx SOx PM VOC NOx SOx PM 

431.1 Sulfur Content of Gasoline Fuels - - 0.93 - - - 0.93 - 

431.2 Sulfur Content of Liquid fuels - - - - - - 0.08 

0.90 

442 Usage of Solvents - - - - 0.30 - - -

 0.99 

461 Gasoline Transfer and Dispensing 0.89 - - - 0.36 - - - 

462 Organic Liquid Loading 0.88 - - - 0.88 - - - 

1102 Dry Cleaners Using Solvents Other Than Perc - - - - 0.17 - - - 

1104 Wood Flat Stock Coating Operations 0.83 - - - 0.83 - - - 

1107 Coating of Metal Parts and Products 0.93 - - - 0.93 - - - 

1110.1&Stationary Internal Combustion Engines - 0.85 - - - 0.24 - - 

1110,2 

1113 Architectural Coatings 0.95 - - - 0.41 

1121 Residential Natural Gas-Fire Water Heaters - - - - - 0.43 - - 

1122 Solvent Degreasers 0.24 - - - 0.12 - - - 

1124 Aerospace Assembly and Component 0.95 - - - 0.89 - - - 

1130 Graphic Arts 0.86 - - - 0.86 - - - 

 0.94 0.94 

1130.1 Screen Printing Operations - - - - 0.90 - - - 

 0.99 

1131 Food Product Manufacturing and Processing - - - - 0.15 - - - 

1132 High Emitting Spray Booth Facilities - - - - 0.44 - - - 

 1.00 

1136 Wood Products Coatings 0.71 - - - 0.24 - - - 

1137 PM10 Reductions from Woodworking Op. - - - - - - - 0.94 

1138 Restaurant Operations 0.85 - - 0.95 0.85 - - 0.95 

1145 Plastic,Rubber and Glass Coatings 0.60 - - - 0.60 - - - 

1146 Non-Residential Boilers, Steam Generator - - - - - 0.81 - - 

1146.2 Large Water Heaters and Small Boilers - 0.97 - - - 0.33 - - 

1158 Storage,Handling,Transport of Petroleum Coke - - - 0.54 - - - 0.21 

1162 Polyester Resin Operations - - - - 0.24 - - - 

 0.77 

1168 Adhesive and Sealant Applications 1.14 - - - 0.33 - - - 

1171 Solvent Cleaning Operations ** 0.58 - - - 0.12 - - - 

1176 Sumps and Wastewater Separators 0.34 - - - 0.34 - - - 

1178 Storage Tanks at Petroleum Facilities - - - - 0.44 - - - 

1186 Paved and Unpaved Roads and Livestock Op. - - - 0.87 - - - 0.67 

 0.99 0.93 

1189 Hydrogen Plant Process Vents - - - - 0.20 - - - 

2202 On-Road MV Mitigation - - - - 0.99 0.99 0.99 0.99

 

_____________________________________________________________________________________________ 

* List only rules have emission impact after 1997. 

** Tier II controls are subject to technology assessment in 2005. 
Chapter 2 Summaries of Emissions 

III-2-7 

Table 2-3 

Growth Surrogates by Source Category 

Group 1: Source Categories Using Industry Output as Growth Factors 

Area Sources 

Source Description Parameter 

Baking – Commercial Manufacturing-Food 

Chemical Processes - 

Fabrication/Manufacturing 

Manufacturing-Rubber 

Degreasing Manufacturing-Total 

Metal Processes - Secondary Product Manufacturing-Metal 

Mineral Processes - Non-Asphalt Manufacturing-Stone, Clay 

Mobile Equipment – Refrigeration Manufacturing-Food 

Solvent Use - Adhesive & Seal Manufacturing-Total 

Solvent Use - Industrial-Misc. Manufacturing-Total 

Solvent Use - Industrial-Fabric Manufacturing-Apparel 

Solvent Use - Industrial-Metal Furn Manufacturing-Furniture 

Solvent Use - Industrial-Paper Manufacturing-Paper 

Solvent Use - Industrial-Marine Manufacturing-Transportation 

Solvent Use - Printing & Publish Manufacturing-Print 

Wine Making - Wine & Brandy Manufacturing-Food 

Wood And Paper - Processing Loss Manufacturing-Furniture 

Point Source Industries 

SIC Source Description 

10-14 Mining 

20-38 Manufacturing 

40 Railroad Transportation 

43 U.S. Postal Service 

46 Pipeline, Except Natural Gas 

48 Communications 
Appendix III Base and Future Year Emission Inventories 

III-2-8 

Table 2-3 

(continued) 

Group 2: Source Categories Using Employment Data As Growth Factors 

Area Sources 

Source Description Parameter (Employment) 

Agricultural Processes – Agricultural Agriculture-Total Employment 

Cooking – Commercial Manufacturing-Total Employment 

Const. & Demolition - Non-Government Construction Employment 

Const. & Demolition – Government Government Employment 

Farming Operations – Agricultural Agriculture-Total Employment 

Fuel Combustion – Agricultural Agriculture-Total Employment 

Fuel Combustion – Commercial Services-Total Employment 

Fuel Combustion –Industrial Manufacturing-Total Employment 

Industrial Equipment - Light Duty Construction Employment 

Mineral Processes - Surface Blasting Total Employment 

Non-Farm Equipment – Heavy Duty Construction Employment 

Other – Unspecified Total Employment 

Pesticide Appli/Use – Agriculture-Synthetic Agriculture-Total Employment 

Pesticide Appli/Use - Non-Agricultural Total-Co Employment 

Solvent Use – Commercial Services-Automobile Employment 

Solvent Use - Dry Cleaning Services-Professional Employment 

Solvent Use - Asphalt Paving/Other Construction Employment 

Waste Burning – Range Management Agriculture-Total Employment 

 

 

 Point Source Industries 

SIC Source Description 

1-9 Agriculture 

15-17 Construction 

39 Miscellaneous Manufacturing 

41 Local & Interurban Transit 

42 Trucking & Warehousing 

44 Water Transportation 

45 Air Transportation 

47 Transportation Services 

49 Gas & Sanitary 

50-51 Wholesale Trade 

52-59 Retail Trade 

60-67 Finance, Insurance & Real Estate 

70-89 Services 

91-97 Public Administration 

Table 2-3 
Chapter 2 Summaries of Emissions 

III-2-9 

(continued) 

Group 3: Source Categories Using SCAG’s Demographic Data as Growth Factors 

Area Source 

Source Description Parameter 

Industrial Equipment - Light Duty Population-SCAG 

Pesticide Applications – Consumer Product Population-SCAG 

Solvent Use – Architectural Housing Unit-SCAG 

Solvent Use - Consumer Product Population-SCAG 

Unplanned Fires - Structural Fire Housing Unit-SCAG 

Utility Equipment - Lawn & Garden (NonCommercial) Housing Unit-SCAG 

Waste Disposal – Landfills Population-SCAG * 

*Wasterecycling programs incorporated. 

Group 4: Source Categories Using VMT as Growth Factors 

Area source 

Source Description Parameter 

On-Road VMT-SCAG 

Paved Road Collector VMT-Collector 

Paved Road Local Street VMT-Local 
Appendix III Base and Future Year Emission Inventories 

III-2-10 

Table 2-3 

(continued) 

 Group 5: Others 

Area Source 

Source Description Parameter Note 

Commercial Boat Activity Forecast (1) 

Fuel Combustion – Petroleum Product Energy Forecast (2) 

Gas Distribution – Transmission Natural Gas Forecast (2) 

Gasoline Dispensing – Tanks/Vehicle Refueling Fuel Consumption (3) 

Mineral Processes – Petroleum Related Energy Forecast (2) 

Windblown Dust No Growth (4) 

Oil & Gas Extraction No Growth (2) 

Oil Production No Growth (2) 

Paved Road – Freeway/Major Arterial Road Miles (5) 

Pesticide Appli/Use - Ag-Non-Synthetic No Growth (6) 

Petroleum Related Source – Petroleum Energy Forecast (2) 

Unpaved Road Dust – Entrained Road No Growth (4) 

Unplanned Fires – Automobile Fire/Wildfires No Growth (4) 

Waste Burning – Forest Mgmt Forest Management (7) 

Waste Disposal – Solvent No Growth (4) 

Non-RECLAIM Power Plants CEC (8) 

Locomotive Activity (9) 

Comments: 

(1) Arcadis, Geraghty and Miller (1999) 

(2) CEC’s 1999 Fuels Report 

(3) CARB EMFAC2002 Burden Model Fuel Consumption Estimates 

(4) Revised Inventory Methodology by District 

(5) Caltrans And CARB Data 

(6) CARB’s Data - No Growth Since 1982 

(7) Angeles National Forest Office 

(8) CEC’s Forecast, 2001 

(9) CARB’s Survey Data 

 
Chapter 2 Summaries of Emissions 

III-2-11 

The demographic forecasts from the year 1997 to the years 2010, and 2020 for 

population, housing, employment, and motor vehicle activity are shown in Table 2-4. 

Table 2-5 exhibits the relative distribution of population by county in the Basin for the 

years 1987, 1990, 1997, 2000, 2010, 2020 and 2025. By 2010 the population in Los 

Angeles county is projected to increase by 10% from 1997 levels, compared with 

increases for Orange (17%), San Bernardino (32%), and Riverside (46%) counties. 

Growth factors for specified ranges of SIC were projected by SCAG (2001), and are 

based on predictions of growth for different industrial sectors per county. SCAG has 

provided growth factors for the years 2000, 2005, 2010, 2015, 2020, 2025 and 2030. 

The growth factors for other years are interpolated between these years. Tables 2-6 and 

2-7 list growth factors for 2010 and 2020 for Los Angeles County, Orange County, 

Riverside County and San Bernardino County in SCAB. 

Table 2-4 

Baseline Socioeconomic Forecasts Used in the 2003 AQMP 

Category 1997 2010 (% Growth) 2020 (% Growth) 

Population 

(Millions) 

14.3 16.5 (+15) 18.2 (+27) 

Housing Units 

(Millions) 

4.6 5.3 (+15) 5.9 (+18) 

Total Employment 

(Millions) 

6.3 7.8 (+24) 8.5 (+35) 

Daily VMT 

(Millions) 

 296.8 387.4 (+31) 454.7 (+53) 

 ______________________________________________________________________________________ 
Appendix III Base and Future Year Emission Inventories 

III-2-12 

Table 2-5 

Population Distribution by County in SCAB (in Thousands) 

Year Los Angeles Orange Riverside San Bernardino Basin Total 

1987 8,250 2,197 627 934 12,008

1990 8,612 2,411 864 1,108 12,995

1997 9,207 2,701 1,093 1,252 14,252

2000 9,412 2,863 1,202 1,348 14,826

2010 10,124 3,168 1,594 1,647 16,533

2020 10,942 3,343 1,997 1,924 18,206

2025 11,428 3,415 2,237 2,089 19,169
Chapter 2 Summaries of Emissions 

III-2-13 

Table 2-6 

SIC Code Growth Factors by County for the Year 2010 

SIC Sector SIC Code Los Angeles Orang

e 

Riverside San Bernardino 

Agriculture 1-9 0.868 0.986 1.019 0.703 

Mining 10-12,14 0.910 0.680 1.200 0.260 

Oil & Gas Extr. 13 1.000 1.000 1.000 1.000 

Construction 15-17 1.354 1.436 2.575 1.602 

Food/Tobacco 20 1.090 1.290 1.470 1.500 

Textile Mill 22 1.430 1.380 1.670 1.660 

Apparel/Other Text. 23 1.390 1.650 1.510 1.450 

Lumber/Wood 24 0.890 1.210 1.360 1.500 

Furniture/Fixtures 25 0.950 1.150 1.520 1.780 

Paper 26 1.270 1.640 1.940 1.510 

Printing 27 1.030 1.630 1.710 2.750 

Chemicals 28 1.280 1.480 1.630 1.880 

Petroleum Products 29 1.000 1.000 1.000 1.000 

Rubber & Plastic 30 1.390 2.130 1.900 2.310 

Leather 31 0.630 0.640 0.860 0.660 

Stone,Clay & Glass 32 1.200 1.110 1.490 1.210 

Primary Metals 33 1.730 1.390 1.760 1.830 

Fabricated Metals 34 1.030 1.420 1.960 1.900 

Machinery 35 2.910 3.840 5.230 7.110 

Electronic Equip. 36 2.430 2.510 4.660 4.120 

Trans. Equip. 37 1.090 1.270 1.850 1.470 

Instruments 38 1.440 2.050 3.620 2.600 

Misc. Mfg. 39 0.902 1.130 1.434 1.477 

Railroads 40 1.530 1.970 1.320 1.550 

Local Transits 41 1.049 1.441 1.167 1.182 

Trucking 42 1.436 1.536 1.970 1.815 

Water Transport 44 1.083 1.111 0.000 0.000 

Air Transport 45 1.100 1.797 2.000 1.243 

Pipelines Trans. 46 1.140 1.360 0.000 1.350 

Travel Services 47 1.754 1.925 0.857 1.000 

Communications 48 1.070 1.830 1.850 2.400 

Utilities 49 1.293 1.579 4.200 2.083 

Wholesales 50-51 1.034 1.413 1.669 1.648 

Retails 52-59 1.023 1.404 1.863 1.531 

Finance 60-62,67 0.923 1.569 1.780 1.557 

Insurance 63-64 1.030 1.656 1.636 1.417 

Real Estate 65,67 1.263 1.529 1.543 1.441 

Hotels 70 1.163 1.350 1.182 1.387 

Personal Services 72 1.282 1.667 1.920 1.590 

Business Services 73 1.549 1.477 2.559 2.093 

Auto Repairs 75-76 1.025 1.758 2.289 1.843 

Motion Pictures 78 1.164 1.500 1.636 1.133 

Amusements 79 1.112 1.554 1.631 1.286 

Health Services 80 1.091 1.151 2.183 1.791 

Legal Services 81 1.245 1.807 1.923 1.476 

Educational Services 82 1.146 1.321 2.300 1.600 

Non-Profit Org. 83,84,86 1.304 1.829 2.188 1.745 

Professional Services 87,89 1.250 1.443 1.923 1.722 

Government 91-97 1.138 1.205 1.563 1.390 

Note: SCAG projections relative to 1997 base year.
Appendix III Base and Future Year Emission Inventories 

III-2-14 

Table 2-7 

SIC Code Growth Factors by County for the Year 2020

SIC Sector SIC Code Los Angeles Orang

e 

Riverside San Bernardino 

Agriculture 1-9 0.706 0.838 1.048 0.676 

Mining 10-12,14 1.120 0.580 1.290 0.260 

Oil & Gas Extr. 13 1.000 1.000 1.000 1.000 

Construction 15-17 1.474 1.524 3.075 1.845 

Food/Tobacco 20 1.200 1.470 1.770 1.760 

Textile Mill 22 1.910 1.830 2.360 2.280 

Apparel/Other Text. 23 1.860 2.280 2.050 1.920 

Lumber/Wood 24 0.890 1.300 1.560 1.700 

Furniture/Fixtures 25 1.000 1.270 1.840 2.160 

Paper 26 1.520 2.050 2.650 1.870 

Printing 27 1.110 1.920 2.140 3.570 

Chemicals 28 1.600 1.890 2.190 2.540 

Petroleum Products 29 1.000 1.000 1.000 1.000 

Rubber & Plastic 30 1.820 3.010 2.750 3.380 

Leather 31 0.590 0.580 0.830 0.530 

Stone,Clay & Glass 32 1.440 1.300 1.930 1.420 

Primary Metals 33 2.600 1.950 2.680 2.760 

Fabricated Metals 34 1.170 1.730 2.690 2.480 

Machinery 35 7.440 10.500 15.920 22.020 

Electronic Equip. 36 5.020 5.200 11.540 9.530 

Trans. Equip. 37 1.260 1.520 2.510 1.820 

Instruments 38 2.010 3.060 6.340 4.110 

Misc. Mfg. 39 0.885 1.162 1.618 1.616 

Railroads 40 2.240 2.950 1.820 2.310 

Local Transits 41 1.066 1.618 1.278 1.318 

Trucking 42 1.559 1.714 2.455 2.213 

Water Transport 44 1.115 1.111 0.000 0.000 

Air Transport 45 1.134 2.344 2.000 1.378 

Pipelines Trans. 46 1.390 1.760 0.000 1.770 

Travel Services 47 1.961 2.660 0.857 1.000 

Communications 48 1.290 2.580 2.770 3.770 

Utilities 49 1.379 1.719 5.700* 2.611 

Wholesales 50-51 1.053 1.607 2.068 1.965 

Retails 52-59 1.037 1.525 2.345 1.835 

Finance 60-62,67 0.934 1.817 2.240 1.871 

Insurance 63-64 1.031 1.988 2.000 1.667 

Real Estate 65,67 1.250 1.741 1.857 1.676 

Hotels 70 1.265 1.417 1.318 1.581 

Personal Services 72 1.449 1.852 2.480 1.897 

Business Services 73 1.858 1.714 3.456 2.702 

Auto Repairs 75-76 1.055 2.000 3.022 2.314 

Motion Pictures 78 1.267 1.656 2.000 1.200 

Amusements 79 1.187 2.096 2.015 1.452 

Health Services 80 1.155 1.199 2.869 2.235 

Legal Services 81 1.392 2.211 2.462 1.762 

Educational Services 82 1.239 1.464 3.067 1.927 

Non-Profit Org. 83,84,86 1.481 2.378 2.881 2.161 

Professional Services 87,89 1.399 1.614 2.462 2.130 

Government 91-97 1.181 1.258 1.865 1.603 

Note: SCAG projections relative to 1997 base year. 

* Utility emissions are mostly limited by RECLAIM, not growth. 
Chapter 2 Summaries of Emissions 

III-2-15 

Future Year Emission Data 

Based on the methodology described above, future year emission inventories data for the 

milestone years 2000, 2002, 2003, 2005, 2006, 2007, 2008, 2010, and 2020 are 

presented in Attachments A (average annual day) B (summer planning inventory) and C 

(winter planning inventory) of this report. These target years are selected to correspond 

to the years required by either the federal or state CAA to demonstrate attainment with 

the corresponding air quality standards. Years 2006, and 2010 are milestones to attain 

PM10, and ozone air quality standards, respectively. Emissions for the year 2020 are 

projected to assess the need for a maintenance plan once all federal standards are 

attained by 2010. 

Emission Trend Analysis 

Figures 2-2 through 2-5 present the relative contributions by source categories (i.e., 

point, area, on-road, and off-road) to total emission levels in 1997 and 2010, 

respectively. As seen in the figures, in 1997 (average annual day) on-road and off-road 

mobile sources are major contributors of CO (97%), NOx (89%), SOx (57%) and VOC 

(65%) emissions. Fine particulate matter (PM10) is produced mostly from entrained road 

dust (53%). For 2010 (average annual day), mobile sources continue to be major 

contributors to total CO, NOx, and SOx emissions by approximately 94%, 89%, and 

68%, respectively. However, contribution to VOC by mobile sources is reduced due to 

the CARB programs. On the contrary, area sources become major contributors to VOC 

emissions (from 28% in 1997 to 36% in 2010). Figures 2-6 through 2-9 illustrate the 

emission trends by pollutant for 1990, 1997, 2006, and 2010. 
Appendix III Base and Future Year Emission Inventories 

III-2-16 

FIGURE 2-2 

Relative Contribution by Source Category to 

1997 Emissions Inventory – Average Annual Day 

VOC Emissions: 1,172 Tons/Day

28%

7%

45%

20%

NOx Emissions: 1,204 Tons/Day

4%

7%

63%

26%

CO Emissions: 6,653 Tons/Day

2%

1%

76%

21%

On-Road Off-Road Point Area Entrained Road Dust

SOx Emissions: 58 Tons/Day

2%

41%

8%

49%

PM10 Emissions: 279 Tons/Day

53%

29%

4%

7%

7%
Chapter 2 Summaries of Emissions 

III-2-17 

SUMMER 

WINTER 

FIGURE 2-5 

Relative Contribution by Source Category to 

2010 Emissions Inventory – Planning Inventory 

FIGURE 2-3 

Relative Contribution by Source Category to 

1997 Emissions Inventory – Planning Inventory 

CO Emissions: 6,461 Tons/Day

18%

78%

1%

3%

NO2 Emissions: 1,278 Tons/Day

24%

64%

7%

5%

VOC Emissions =1,222 Tons/Day

22%

42%

8%

28%

NOx Emissions = 1,165 Tons/Day

27%

62%

7%

4%

Point Area On-Road Off-Road 
Appendix III Base and Future Year Emission Inventories 

III-2-18 

FIGURE 2-4 

Relative Contribution by Source Category to 

2010 Emissions Inventory –Average Annual Day

VOC Emissions: 630 Tons/Day

36%

11%

34%

19%

NOx Emissions: 780 Tons/Day

5%

56% 6%

33%

CO Emissions: 3,359 Tons/Day

5%

1%

61%

33%

SOx Emissions: 60 Tons/Day

2%

30%

4%

64%

PM10 Emissions: 301 Tons/Day

49%

33%

5%

6%

7%

On-Road Off-Road Point Area Entrained Road Dust
Chapter 2 Summaries of Emissions 

III-2-19 

SUMMER 

WINTER 

FIGURE 2-5 

Relative Contribution by Source Category to 

2010 Emissions Inventory – Planning Inventory 

FIGURE 2-5 

Relative Contribution by Source Category to 

2010 Emissions Inventory – Planning Inventory 

CO Emissions: 3,315 Tons/Day

27%

61%

2%

10%

NO2 Emissions: 820 Tons/Day

30%

57%

6%

7%

VOC Emissions: 659 Tons/Day

21%

32%

13%

34%

NOx Emissions: 764 Tons/Day

35%

54%

7%

4%

On-Road Off-Road Point Area 
Appendix III Base and Future Year Emission Inventories 

III-2-20 

FIGURE 2-6A 

VOC Emission Trend by Source Category - Average Annual Day 

FIGURE 2-6B 

VOC Emission Trend by Source Category - Summer Planning 

0

400

800

1200

1600

2000

1990 1997 2006 2010

Point Area On-Road Off-Road

1780

1,172

630

698

Tons/Day 

0

400

800

1200

1600

2000

2400

1990 1997 2006 2010

Point Area On-Road Off-Road

1,869

1,222

730 659

Tons/Da

y
Chapter 2 Summaries of Emissions 

III-2-21 

FIGURE 2-7A 

NOx Emission Trend by Source Category - Average Annual Day 

FIGURE 2-7B 

NOx Emission Trend by Source Category - Summer Planning 

0

200

400

600

800

1000

1200

1400

1600

1800

1990 1997 2006 2010

Point Area On-Road Off-Road

1,592

1,204

780

950

0

300

600

900

1200

1500

1800

1990 1997 2006 2010

Point Area On-Road Off-Road

1,546

1,165

764

929

Tons/Da

y Tons/Da

y
Appendix III Base and Future Year Emission Inventories 

III-2-22 

FIGURE 2-8A 

CO Emission Trend by Source Category - Average Annual Day 

FIGURE 2-8B 

CO Emission Trend by Source Category - Winter Planning 

0

1500

3000

4500

6000

7500

9000

10500

12000

1990 1997 2006 2010

Point Area On-Road Off-Road

10,589

6,653

3,359

3,973

Tons/Da

y

0

1500

3000

4500

6000

7500

9000

10500

12000

1990 1997 2006 2010

Point Area On-Road Off-Road

10,328

6,461

3,315

3,907

Tons/Da

y
Chapter 2 Summaries of Emissions 

III-2-23 

FIGURE 2-9 

PM10 Emission Trend by Source Category - Average Annual Day 

VOC Emissions

As presented in Figure 2-6, emissions from area sources, off-road mobile sources and on-road 

mobile sources all show a significant decrease. Area source emissions are projected to drop 

from 333 tons/day in 1997 to 224 tons/day in 2010. Between 1997 and 2010, emissions from 

off-road mobile sources are expected to fall from 237 tons/day to 123 tons/day, while on-road 

emissions should fall from 519 tons/day to 212 tons/day. Area source reductions are derived 

mainly from the District’s adopted rules for gasoline transfer and dispensing (Rule 461), 

architectural coatings (Rule 1113), solvent degreasing (Rule 1122), and solvent cleaning 

operations (Rule 1171). Off-road reductions result primarily from emission controls for sparkignition marine engines; new emission standards for small and large gasoline powered engines, 

and liquefied petroleum gas (LPG) used in off-road equipment. Since its adoption in 1990, 

California’s Low Emission Vehicle I (LEV I) program has produced significant emission 

reductions from on-road passenger vehicles by relying on a systems-wide approach to achieve 

reductions from fuels and mobile source exhaust and evaporative emissions. Both LEV I and 

LEV II, adopted in 1998, include four primary elements: (1) increasingly stringent exhaust 

emission standards, (2) an increasingly stringent annual fleet average standard for non-methane 

organic gas (NMOG), (3) banking and trading provisions, and (4) a requirement that a specific 

percentage of vehicles be Zero Emission Vehicles (ZEVs), vehicles with no emissions. Under 

LEV II, sport utility vehicles, pick-up trucks, and mini-vans must achieve the same emission 

standards as cars, beginning in 2004-2007. Other programs to reduce emissions from mobile 

sources include: (1) the Carl Moyer program, which provides financial incentives for the early 

0

100

200

300

400

500

600

1990 1997 2006 2010

Point Area On-Road Off-Road

279

339

293 301

Tons/Day
Appendix III Base and Future Year Emission Inventories 

III-2-24 

introduction of clean heavy-duty engines, (2) regulations to reduce emissions from on-road 

heavy-duty engines and vehicles, (3) low sulfur diesel and cleaner burning gasoline 

requirements, (4) smog check programs, and (5) District and CARB fleet rules. 

NOx Emissions

Figure 2-7 illustrates the NOx emissions by major source category. NOx emissions from both 

off-road mobile (312 tons/day to 257 tons/day) and on-road mobile (761 tons/day to 434 

tons/day) sources are projected to decrease substantially between 1997 and 2010. The 

reductions largely reflect the replacement of existing engines and vehicles with cleaner models 

as rules are implemented and vehicle fleets turn over. As mentioned above, programs to reduce 

off-road emissions result primarily from emission controls for spark-ignition marine engines; 

new emission standards for small and large gasoline powered engines, and liquefied petroleum 

gas (LPG) use in off-road equipment. On road emission reductions derive from CARB’s LEV 

programs, low-sulfur diesel fuel and cleaner-burning gasoline requirements, regulations to 

reduce emissions from on-road heavy-duty engines and vehicles, smog check requirements, and 

other programs. 

CO Emissions

Figure 2-8 shows CO emissions over a period of time. Almost all of the CO emissions are from 

mobile sources. The drastic reduction between 1997 and 2010 is from on-road mobile sources 

(5092 tons/day to 2048 tons/day). The LEV program has been particularly effective in reducing 

carbon monoxide emissions from on-road vehicles. 

PM10 Emissions

Figure 2-9 shows the PM10 emission trend. About half of the emissions are from road dust. The 

amount of dust is projected to stay constant between 1997 and 2010. (147 tons/day and 147 

tons/day respectively) 

Growth Impact 

Despite rules and regulations adopted by SCAQMD, CARB and U.S. EPA as of October 31, 

2002, the projected future emissions are still above the levels required for achieving federal 

and state air quality standards. The main reason is that the region as a whole is projected to 

continue to grow in population; housing, employment and vehicle miles traveled (VMT). 
Chapter 2 Summaries of Emissions 

III-2-25 

To illustrate the impact from the growth, year 2010 no-growth emissions were estimated by 

removing the growth factors from the 2010 baseline emissions. Table 2-8 presents the 2010 

forecasted emission estimates with and without growth. 

Table 2-8 

Growth Impact to 2010 Annual Average Emissions in Tons Per Day 

With Growth VOC NOx CO SOx PM10 

 Point 72 47 48 18 14 

 Area 224 42 168 1 100 

 Road Dust 147 

 On-Road 212 435 2048 2 21 

 Off-Road 122 256 1094 39 19 

 Total 630 780 3358 60 301 

No Growth VOC NOx CO SOx PM10 

 Point 54 44 38 18 11 

 Area 190 37 113 1 77 

 Road Dust 134 

 On-Road 175 356 1679 2 17 

 Off-Road 106 222 948 33 17 

 Total 525 659 2778 54 256 

Mobile and Area Source Credit Programs 

In 2001, the AQMD Governing Board adopted six mobile and area source pilot credit 

generation rules: Rule 1612.1 - Mobile Source Credit Generation Pilot Program, Rule 

1631 – Pilot Credit Generation Program for Marine Vessels; Rule 1632 – Pilot Credit 

Generation Program for Hotelling Operations; Rule 1633 – Pilot Credit Generation for 

Truck/Trailer Refrigeration Units; Rule 1634 – Pilot Credit Generation Program for 

Truck Stops; and Rule 2507 – Pilot Credit Generation Program for Agricultural Pumps. 

NOx emission reductions generated from these pilot credit generation rules can be used in 

the RECLAIM program either directly or through the RECLAIM Reserve under the 

Executive Order (EO) Mitigation Fee Program for power producing facilities and in the 

Air Quality Investment Program (AQIP) for specific RECLAIM facilities. 

All six pilot credit generation rules have been submitted to EPA for inclusion in the State 

Implementation Plan (SIP). The first five pilot credit generation rules, Rules 1612.1, 

1631, 1632, 1633, and 2507 have been approved by CARB and EPA. EPA published 

their final approval of the five pilot credit generation rules on February 19, 2002. Rule 

1634, submitted to CARB and EPA after its adoption in November 2001, is currently 
Appendix III Base and Future Year Emission Inventories 

III-2-26 

being reviewed by EPA. As part of EPA requirements, the AQMP needs to identify 

these emissions explicitly. Table 2-9 lists these emissions. 

 

Federal and state approval of the first five pilot credit generation rules represents a 

significant milestone in market incentives programs as they are the first mobile source 

credit generation rules to receive federal approval. These rules will provide an important 

option to RECLAIM facilities if the demand for RTCs increases and will also enable 

AQMD to use these credits to mitigate excess emissions from power plants. 

Table 2-9 

Credit Rules and Associated 1997 Annual Emissions (Tons/Day) 

Rule Name Target Sources VOC NOx CO SOx PM1

0 

1612.

1 

Mobile Sources On-Road Heavy-HeavyDuty Trucks and Yard 

Hostlers 

 8.9 198.2 41.8 1.8 6.0 

1631 Marine Vessels Commercial Boats 0.4 9.5 1.3 0.1 0.1 

1632 Hotelling 

Operations 

Ship Berthing 1.7 10.7 1.5 7.9 0.7 

1633 Truck/Trailer 

Refrigeration 

Transportation 

Refrigeration Unit 

 1.7 10.2 5.4 0.05 1 

1634 Truck Stops Truck Idling 0.1 1.5 0.5 .004 .018 

2507 Stationary 

Agricultural 

Pumps 

Agricultural Irrigation 

Pumps 

 0.1 1.6 0.3 .024 0.109 
Chapter 2 Summaries of Emissions 

III-2-27 

CONTROLLED EMISSIONS INVENTORIES 

This section describes the methodology used to estimate the controlled and remaining 

emissions after the proposed control measures in the 2003 AQMP are implemented for 

the years 2006, and 2010. Emission reductions are derived from applying the control 

efficiency of a control measure to the projected baseline inventories. 

In addition to the proposed control measures, the impacts of NSR-related set aside 

tracking and other budgeted emissions for various District programs (e.g., RECLAIM, 

HILO) are also discussed in this section. 

To project emission reductions and remaining emissions from the implementation of the 

proposed control measures, a mathematical algorithm called Controlled Emissions 

Projection Algorithm (CEPA) is used. CEPA is developed to calculate projected 

remaining emissions and/or emission reductions for specified control scenarios. CEPA 

is briefly discussed in this section. A more comprehensive and extensive discussion of 

CEPA is presented in Technical Report III-A of the 1991 AQMP. 

Emission Impacts of SCAQMD Programs 

There are several SCAQMD regulatory programs that have specific impacts on future 

emissions through certain “set-aside” or exemption provisions. As a result, special 

emission accounts were created for the 2003 AQMP to track these emissions. For air 

quality modeling purposes, these emissions (except RECLAIM allocations) are 

distributed across the entire non-RECLAIM point source inventory and the RECLAIM 

Hi-Lo

In order to encourage new business locating to the Basin, a Clean Air Bank was 

established for high employment – low polluting (HILO) companies. RECLAIM 

companies creating a minimum of 500 job positions and emitting at a rate (on a per 

employee basis) less than half of the AQMP 2010 goal would be exempt from NSR 

offset requirements. As a result, 0.25 tons/day of NOx and SOx (each) were set aside for 

this purpose, in the RECLAIM baseline emissions. 

RECLAIM Allocation

Future year emissions for RECLAIM facilities were based on their initial allocation as 

specified in Rule 2002 as well as trading transactions as of February, 2001. Reported 

1996-1997 emissions for Cycle I and Cycle II facilities were used for the calendar year 

1997. Over forty facilities joined the RECLAIM universe in 1999 either because the 

facilities had grown to over 4 tons per year for NOx or SOx, or because they opted to 

expand in the future. Amendments to allocations as a result of the change in the 

RECLAIM universe were incorporated into the 2003 AQMP. 
Appendix III Base and Future Year Emission Inventories 

III-2-28 

SIP Set Aside Accounts

 Background 

The 2003 AQMP includes an emissions set aside to account for growth from new and 

modified sources, the Offset Budget, the potential increase from VOC emissions from 

the phase-out of ozone depleting compounds (ODCs) or toxic air contaminants, and a 

SIP Reserve for potential technology assessments. As shown in Table 2-10, the total 

2010 emissions to account for growth and the various set-aside emissions accounts is 

approximately 14 tons per day of VOC, 4 tons per day of NOx, 2 tons per day of CO, 2 

tons per day of SOx and 1 ton per day of PM10. The methodology and assumptions 

used to develop these set-aside accounts for the 2003 AQMP are discussed in detail 

below. It should be noted that emission increases or decreases discussed herein are in 

reference to the projected AQMP baseline emissions without the effect of 

implementation of the AQMD’s New Source Review program. 

Table 2-10 

Summary of Emissions Growth Set-Aside for the 2003 AQMP 

(Tons per Day) 

VO

C 

NO

x 

CO SO

x 

PM1

0 

New and Modified Sources 8.73 0.07 0.80 0.76 0.23

Offset Budget N/A 1.00 1.00 1.00 1.00

VOC Emissions from Phase-out of 

ODCs or Toxics 2.00 N/A N/A N/A N/A

SIP Reserve (Potential Tech 

Assessments) 3.00 2.00 0.00 0.00 0.00

Total - 2010 Emissions 13.73 3.07 1.80 1.76 1.23

Growth from New and Modified Sources

The 2003 AQMP accounts for growth from new and modified sources based on 

emissions offsets used and generated through the AQMD’s New Source Review 

program. The AQMD’s Regulation XIII – New Source Review (NSR) program is an 

emission reduction control strategy program as it requires new and modified sources to 

meet a Best Available Control Technology (BACT) emissions level (which is generally 

cleaner than a Best Available Retrofit Control Technology (BARCT) emissions level, 

and all external offsets must be traded at a 1.2 to 1 trading ratio. In addition, the 

AQMD’s New Source Review program requires that all emission increases from new 

and modified sources be fully offset. Emissions offsets are obtained from either the 

open market or from the AQMD’s NSR Account. In general, any facility with a 

potential to emit greater than or equal to four tons per year of VOC, NOx, SOx, or PM10 
Chapter 2 Summaries of Emissions 

III-2-29 

or 29 tons per year of CO must provide offsets or Emission Reduction Credits (ERCs) 

for all increases of that pollutant from the open market. Emission increases from sources 

below these emissions thresholds or specific source categories that are exempt from 

obtaining offsets from the open market can obtain emission offsets from the AQMD’s 

NSR Account. 

Overall Approach and Methodology

The following five steps were used to estimate the potential increase in emissions from 

new and modified sources by the year 2010: 

Step 1: Estimate annual average net demand from open market 

Step 2: Calculate 2010 Net Demand for Open Market 

Step 3: Estimate annual average net demand from AQMD’s NSR Account 

Step 4: Calculate 2010 Net Demand for AQMD’s NSR Account 

Step 5: Total 2010 Net Demand from New and Modified Sources 

In general, the annual average net demand from the open market and the AQMD’s NSR 

Account are estimated based on historical records. Based on the annual average net 

demand, the 2010 net demand from the open market and the AQMD’s NSR Account are 

calculated. The sum of the 2010 net demand from the open market and the AQMD’s 

NSR Account represents the potential 2010 emissions from new or modified sources. 

The net demand simply represents the emission increases in the future years to be offset 

by reductions previously banked (i.e., prior to the AQMP base year). Each of these steps 

are discussed in more detail below. 

 Step 1: Estimating Annual Average Net Demand from Open Market 

To account for emissions growth from sources that are accessing the open market, the 

AQMD staff assessed the net annual average demand of ERCs from the open market 

between 1997 and 2001. The net annual average demand for ERCs from the open 

market is based on the difference between the annual average demand and supply of 

ERCs. 

Net Annual Average Demand for ERCs = Annual Average Demand of ERCs – Annual 

Average Supply of ERCs 

As shown in Table 2-11 below, the net annual average demand for ERCs in the open 

market ranges from 0.01 to .56 tons per day, depending on the pollutant. 

Table 2-11 

Annual Average Net Demand for ERCs in the Open Market 

(Tons per Day) 
Appendix III Base and Future Year Emission Inventories 

III-2-30 

VOC NOx CO SOx PM1

0 

Annual Average 

Demand1

0.59 0.01 0.12 0.01 0.04 

Annual Average 

Supply2

0.03 0.00 0.01 0.00 0.01 

Net Annual 

Average Demand 

0.56 0.01 0.11 0.01 0.03 

1 Annual average use of ERCs from the open market. Based on 1998-2001 for CO, PM10, SOx, and NOx, and 

2000-2001 for VOC. Average use excludes electric generating facilities and non-Regulation XIII offsetting 

uses. Annual average use adjusted by 80 percent to reflect actual emissions. 2 Annual average supply is based on ERCs issued from 1998 to 2002. Annual average use is divided by 1.2 to 

account for the trading ratio applied to all external offsets and multiplied by 80 percent to reflect actual 

emissions. 

Annual Average Demand for ERCs in the Open Market

The annual average demand for the five criteria pollutants are presented in Table 2-11 

above. The annual average demand is based on ERCs used from 1998 through 2001 for 

CO, PM10, SOx and NOx, and based on ERCs used from 2000 and 2001 for VOC (no 

VOC ERC use data in 1998 and 1999). In addition, the annual average use is based on 

ERCs use from non-electric generating facilities, and excludes those ERCs that were 

used for CEQA mitigation, orders of abatements, interdistrict transfers, non-VOC 

removal, Rule 2202, and variances. The annual demand, which is based on the facilities’ 

permitted emissions level is adjusted to reflect the actual amount of emissions that are 

emitted into the air. It is assumed that actual emissions represent 80 percent of permitted 

emissions. This ratio of permitted to actual emissions is currently being used Report on 

the Effectiveness of Regulation XIII – New Source Review (AQMD, 1988). 

Annual Average Supply for ERCs in the Open Market

The annual average supply for the five criteria pollutants are presented in Table 2-11 

above. The annual average supply is based on ERCs issued from 1998 through 2002. 

Under Regulation XIII, sources that are using external offsets, or ERCs not generated 

within their facility must apply a trading ratio of 1.2 to 1. To more accurately reflect the 

actual supply of ERCs that are needed to offset emission increases, the trading ratio was 

backed out of the annual ERC supply by dividing the annual issuance of ERCs by 1.2. 

In addition, similar to the ERCs used, the amount of ERCs issued was adjusted by 80 

percent to reflect actual emissions that are offset as compared to the permitted emissions 

level. 

 Step 2: Calculate 2010 Net Demand for Open Market 

For the purpose of estimating the emissions growth from newly permitted sources in the 

2003 AQMP, it is assumed that each year, beginning in 2003, there is an incremental 
Chapter 2 Summaries of Emissions 

III-2-31 

emissions increase equivalent to the annual average net demand for ERCs in the open 

market. The maximum amount of growth that can be realized in future years is assumed 

to be capped by the current available supply of ERCs in the open market. The 2010 net 

demand for the open market represents the amount of emissions growth at a BACT level 

that is expected to occur by 2010. This estimate was based on the annual average net 

demand for each pollutant. Each year beginning in 2003, the annual average net demand 

is cumulatively added over the next seven years to 2010. Table 2-12 summarizes the 

annual average net demand for offsets by the year 2010 from the open market. 

Table 2-12 

2010 Net Demand for ERCs in the Open Market 

(Tons per Day)

VOC NOx CO SOx PM1

0 

2010 Net Annual 

Average Demand 

3.90 0.07 0.80 0.06 0.23 

1 2010 Net Annual Average Demand is based on the cumulative net average demand from 2003 to 2010. 

 Step 3: Estimating Annual Average Net Demand from AQMD’s NSR Account 

Sources accessing the AQMD’s NSR Account include those sources that are exempt 

from obtaining offsets from the open market. To estimate emissions growth from these 

sources, the net annual average amount of offsets being used and generated was 

estimated. The net annual average amount of offsets is based on the difference between 

the annual average demand and supply of offsets from the AQMD’s NSR Account. 

Annual average demand and supply of offsets are averaged over a four-year period, from 

July 1997 to August 1998, from July 1998 to August 1999, from July 1999 to August 

2000, and from July 2000 to August 2001. Annual demand and supply of offsets from 

the AQMD’s NSR Account is based on data reported in the AQMD’s Annual 

Effectiveness Reports on Regulation XIII. 

The net annual average demand and supply is the difference between the annual average 

demand minus the annual average supply of offsets from the AQMD’s NSR Account. 

As shown in Table 2-13, the net annual average demand and supply from the AQMD’s 

NSR Account is positive for VOC and CO, and negative for NOx and PM10. Values 

that are negative represent those pollutants where the annual average supply of offsets is 

greater than the annual average demand of offsets. For SOx, on average the amount of 

credits used and generated is even. 
Appendix III Base and Future Year Emission Inventories 

III-2-32 

Table 2-13 

Annual Average Net Demand for Offsets in the AQMD’s NSR Account1

(Tons per Day) 

 VOC NOx CO SOx PM1

0 

Annual Average 

Demand1

3.79 0.84 0.83 0.04 0.18 

Annual Average 

Supply2

3.10 1.16 0.73 0.04 0.72 

Net Demand and 

Supply from 

AQMD’s NSR 

Account 

0.69 -0.32 0.10 0.00 -0.54 

1 Based on annual use of offsets from the AQMD’s NSR Account, which includes offsets used sources below 

emissions thresholds, priority reserve, and Rule 1304 offset exemptions. Average annual use based on data 

from the 1997/1998, 1998/1999, 1999/2000/ and 2000/2001 Annual Effectiveness Report on Regulation XIII – 

New Source Review. 

2 Based on annual supply of offsets into the AQMD’s NSR Account, which includes offsets generated from 

orphan shutdowns, surplus reduction credits, BACT and other discount of ERCs, and positive balance 

adjustments. Average annual use based on data from the Annual Effectiveness Report on Regulation XIII – 

New Source Review, for the reporting periods from July 1997 to August 1998, from July 1998 to August 1999, 

from July 1999 to August 2000, and from July 2000 to August 2001. 

Annual Average Demand and Supply for ERCs from the AQMD’s NSR 

Account

Table 2-13 above summarizes the annual average demand and supply of offsets from the 

AQMD’s NSR Account, based on accounting to satisfy equivalency with the state new 

source review requirements. The annual demand is based on those sources that are 

eligible to use offsets from the AQMD’s NSR Account or are exempt from providing 

offsets from the open market, of which include facilities with a potential to emit less than 

four tons per year of VOC, NOx, SOx, or PM10 or 29 tons per year of CO annual 

emissions; sources eligible for the priority reserve; and sources exempt from providing 

offsets pursuant to Rule 1304. The annual demand, which is based on the facilities’ 

permitted emissions level is adjusted to reflect the actual amount of emissions that are 

emitted into the air. It is assumed that actual emissions represent 40 percent of permitted 

emissions. In an analysis conducted by the AQMD staff in 1998 for sources less than 

four tons per year, actual emissions were less than 40 percent of permitted emissions. 

(AQMD, 1988). It should be noted, however, as a conservative estimate the Annual 

Report on the Effectiveness for Regulation XIII assumes that actual emissions represent 

80 percent of permitted emissions. The annual supply is based on offsets that go into the 

AQMD’s NSR Account such as credits generated from orphan shutdowns; surplus 

reduction credits; BACT and other discount of ERCs; and positive balance adjustments 

by way of ERCs. 
Chapter 2 Summaries of Emissions 

III-2-33 

 Step 4: Calculate 2010 Net Demand for AQMD’s NSR Account 

For the purpose of estimating the emissions growth from newly permitted sources in the 

2003 AQMP, it is assumed that each year, beginning in 2003, there is an incremental 

emissions increase equivalent to the annual average net demand for offsets in the 

AQMD’s NSR Account. The maximum amount of growth that can be realized in future 

years is assumed to be capped by the current available supply of offsets in the AQMD’s 

NSR Account. The 2010 net demand for the open market represents the amount of 

emissions growth at a BACT level that is expected to occur by 2010. This estimate was 

based on the annual average net demand for each pollutant. For NOx and PM10, where 

the net annual average demand for offsets was negative, indicating that the annual 

average supply of offsets is greater than the use, it assumed that there is no additional 

emissions growth in 2010 from sources accessing the AQMD’s NSR Account. Similarly 

for CO, as the net annual average demand for offsets was zero. For VOC and SOx, each 

year beginning in 2003, the annual average net demand is cumulatively added over the 

next seven years to 2010. Table 2-14 summarizes the annual average net demand for 

offsets by the year 2010 from the AQMD’s NSR Account for the five criteria pollutants. 

Table 2-14 

2010 Net Demand for ERCs in the AQMD’s NSR Account 

(Tons per Day) 

 VOC NOx CO SOx PM1

0 

2010 Net Annual 

Average Demand 

4.83 0.00 0.00 0.70 0.00 

2 2010 Net Annual Average Demand is based on the cumulative net average demand from 2003 to 2010 

 Step 5: Total 2010 Net Demand from New and Modified Sources 

The total 2010 emissions growth from new and modified sources is equivalent to the 

sum of the 2010 net annual average demand for the open market and the 2010 net annual 

average demand for the AQMD’s NSR Account. Table 2-15 summarizes the total 2010 

emissions growth new and modified sources. 

Table 2-15 

Total 2010 Net Demand from New and Modified Sources 

(Tons per Day) 

 VOC NOx CO SOx PM1

0 

2010 Net Annual 

Average Demand 

8.73 0.07 0.80 0.76 0.23 

3 2010 Net Annual Average Demand is based on the sum of the 2010 net demand from the open market and 

the AQMD’s NSR Account. 
Appendix III Base and Future Year Emission Inventories 

III-2-34 

 NSR Reduction Benefit

Since the AQMP future year baseline inventories already include emissions growth 

based on SCAG projections in the absence of NSR constraints, adding additional related 

emissions growth to the baseline inventories would be overstating the potential growth. 

Therefore, reconciliation of growth projections between existing sources and new 

sources are necessary. Following a similar methodology employed in the 1997 AQMP, 

emission reductions attributable to the NSR program due to installation of BACT rather 

than BARCT were estimated. For VOC and SOx sources, it is assumed that BACT and 

BARCT are the same. For NOx, CO, and PM10, it is assumed that BACT represents 

approximately 60 percent of BARCT emissions. 

Table 2-16 

Estimated Emission Reduction Benefit from 

Installation of BACT for New and Modified Sources 

(Tons per Day) 

 VOC

1

NOx2 CO2

 SOx1 PM10

2

Estimated New 

and Modified 

Sources (2010) 

8.73 0.07 0.80 0.76 0.23 

Emission 

Reduction 

Benefit 

8.73 0.12 1.3 0.76 0.38 

1 Assumed that BACT = BARCT for VOC and SOx sources. 2

 Assumed that BACT = 60% of BARCT. 

 Offset Budget

Rule 1309.2 – Offset Budget creates an emissions bank to provide offsets to sources that 

otherwise cannot obtain offsets. Strict eligibility requirements are placed on the offset 

budget. Only those sources which are not exempt from offsets under Rule 1304 – 

Exemptions; and not eligible for offsets under Rule 1309.1 – Priority Reserve; can apply 

for offset budget credits. Other eligibility criteria include a facility having all sources at 

or below BARCT and conducting a good faith effort to obtain open market offsets. 

Finally, a non-refundable mitigation fee is required for each pound of credits obtained. 

The Offset Budget will be funded by expired permit source shutdown credits, emissions 

reductions from projects funded by mitigation fees collected, and other methods 

approved by the Executive Officer, CARB and U.S. EPA. The initial funding of the 

Offset Budget will be from expired permit source shutdown credits for the years 2000 

through 2002. 
Chapter 2 Summaries of Emissions 

III-2-35 

The 2003 AQMP includes a set aside account of one ton per day for each criteria 

pollutant for the Offset Budget. This line item is to account for emissions that may not 

be included in the AQMP baseline inventories. As such, the set aside account should not 

be viewed as the cap for the Offset Budget. Furthermore, AQMP inventories are based 

on actual emissions not potential to emit or offsets needed under New Source Review. 

The Offset Budget is designed to be a source of offsets, but used as a “bank of last 

resort.” It ensures the availability of offsets, but encourages sources to seek offsets from 

the open market first. 

 VOC Emissions from Phase-Out ODCs and Toxics 

The 1997 AQMP included an emissions set-aside for potential VOC emissions increases 

from the phase-out of ozone depleting compounds (ODCs). The 1997 AQMP set aside 

approximately 10 tons per day of VOC emissions due to the potential conversion of 

ODCs to VOC containing materials. Based on historical use, the 2003 AQMP modifies 

the amount of the set aside to 2 tons per day of VOC emissions for the potential increase 

in VOC emissions from the conversion of ODCs to VOC containing materials and the 

potential conversion of toxic materials to VOC containing materials. 

 SIP Reserve for Potential Technology Assessments 

To achieve air quality goals, adopted and amended rules and regulations that rely on 

technology forcing emission limits are often needed. Technology forcing emission 

limits are designed to provide ample time for the development and implementation of 

new air pollution technologies. In the event, however, that the new air pollution control 

technology does not come to fruition by the implementation date of the adopted or 

amended rule there may be a need to delay or relax the future emission limits. The SIP 

Reserve is designed to ensure that delaying or relaxing future emission limits for 

technology forcing rules will not interfere with the Basin’s attainment demonstration. In 

addition, the SIP Reserve allows the AQMD to adopt and amend rules with technology 

forcing limits while maintaining SIP approvability if a rule relaxation or delay is needed. 
Appendix III Base and Future Year Emission Inventories 

III-2-36 

 Summary 

For the purpose of attainment demonstration and rate of progress, additional emissions 

are included in the controlled emissions after implementation of proposed control 

measures. These emissions are estimated based on the difference between emission 

estimates presented in Tables 2-10 and 2-16. Table 2-17 summarizes the emissions 

added to controlled emissions for attainment demonstration. 

Table 2-17 

Emissions Added to Controlled Emissions for Attainment Demonstration 

(Tons per Day) 

 VOC NOx CO SOx PM10 

Total - 2010 Emissions 

(Table 2-10) 

13.7

3 

3.0

7 

1.8

0 

1.7

6 

1.2

3 

Emission Reduction 

Benefit (Table 2-16) 

8.73 0.1

2 

1.3

0 

0.7

6 

0.3

8 

2010 Emissions Added to 

Controlled Emissions 

5.00 2.9

5 

0.5

0 

1.0

0 

0.8

5 

Proposed Control Measures 

In order to assess emission reduction potential and remaining emissions from proposed 

control measures, a control factor profile needs to be developed identifying source 

category targeted by a measure, its control efficiency, and implementation schedule. 

Control Efficiency/Control Factor

One factor that determines the effectiveness of a control measure is its control efficiency 

(CE), expressed in percentage. Control efficiency is dependent on the specific control 

technologies proposed, and each control measure may have one or perhaps more if 

several control technology options are available. If there is only one feasible control 

technology in a control measure, its control efficiency is primarily based on an 

engineering evaluation of the proposed technology. However, if several control 

technologies are available to control an emission source, the average control efficiency 

is used. If multiple control technologies are proposed to reduce emissions from various 

steps of an operation, a weighted average control efficiency is developed to represent an 

overall control of the emission sources. Once the control efficiency of a control measure 

is determined, it is used to estimate emission reductions of the proposed measure. 

Control efficiencies for the proposed control measures are identified and discussed in 

detail in Appendix IV of the 2003 AQMP. 

The control factor (CF) is used to estimate remaining emissions once a proposed control 

measure is implemented. A control factor equal to 0 indicates complete emission control 
Chapter 2 Summaries of Emissions 

III-2-37 

or 100 percent efficiency. A control factor equal to 1 indicates no emission control or 

emission unchanged. A high control factor value indicates a low control efficiency. As 

the control efficiency goes up, the control factor value goes down and approaches 0. 

Thus, the equation to calculate a control factor is as follows: 

CF = 1 - (CE/100) 

And, the remaining emissions can be calculated as 

REM = BE * CF 

Where REM is Remaining Emissions, and BE is Baseline Emissions 

The 2003 AQMP has many milestones for which emission reduction progress needs to 

be projected. As a result, control factors for each milestone year have to be developed. 

Such a control factor profile for each measure is developed considering the following 

factors: 

• proposed adoption date, 

• implementation lead time 

• phase-in period, if any. 

The adoption date as proposed in the 2003 AQMP is the date the District is expected to 

adopt the control measure as a rule. The implementation lead time reflects the time 

allowed for the emission sources to install controls. When a rule is implemented, it is 

not unusual that it may have multiple interim implementation dates prior to full 

implementation. This is because the requirements in a rule may require two or three 

phases to reach the final emission target (e.g., a technology-forcing regulation). Or, a 

rule may regulate such a large population of equipment that it is impractical to 

implement it all at once, and it becomes administratively necessary to phase in its 

implementation. In either case, a control profile would indicate an initial 

implementation date and an ending implementation date. The adoption and 

implementation schedule of the proposed control measures is presented in Chapter 7 of 

the 2003 AQMP. 

Measure Impact Sources 

Each proposed control measure describes specific emission sources subject to potential 

controls. Based on the description of these sources, corresponding sources as tracked in 

the emission inventory are identified. In general, emission sources are grouped by major 

source category, which can be further subcategorized into point sources denoted by 

Source Classification Codes (SCC) and area sources denoted by Category Emission 

Source (CES) Codes. To track emission reductions more accurately, the control factors 

at the SCC/CES level become necessary. 
Appendix III Base and Future Year Emission Inventories 

III-2-38 

An SCC, an 8-digit EPA code, is used to identify emissions from a point source at the 

equipment level. A CES, a 5-digit CARB code, is used to describe an area source for 

which emissions are distributed across the region with no specific locations. 

For some measures the controls target not only the type of equipment, but also the 

industries engaged in. In those cases, control factors will be developed by pairing SCCs 

and Standard Industrial Classification (SIC) Codes to clearly and specifically point out 

the emission sources in the inventory that the measure designs to reduce. Such 

SCC/SIC pairs significantly enhance the ability to quantify emissions closely following 

the intent of a proposed control measure. 

In spite of significant progress made in identifying emissions at the SCC or CES level, 

there are still instances where an SCC or CES category is not fully impacted by a control 

measure. As a result, an impact factor (IF) is developed as a weighing factor for such an 

adjustment. For example, an IF of 0.58 was used for some thinning solvent sources to 

account for the portion of emissions reductions from Rule CTS-02 (Solvent Cleaning 

Operations). In this case, CF is calculated as 

CF = 1 - ( (CE /100) x IF ) 

Impact factors will accurately track the measure baseline emissions, and calculate the 

true reductions from the proposed control measures. 

CEPA Emission Calculations

The District uses the CEPA program to calculate emission projections for the proposed 

AQMP control measures. Based on the control factor profile and projected baseline 

emissions, CEPA estimates emission reductions and remaining emissions for future 

years by pollutant (i.e., summer VOC and NOx; winter CO and NO2; and average annual 

day for VOC, NOx, CO, SOx and PM10). 

CEPA allows interaction of multiple control measures affecting a specific emission 

source, avoiding double counting of emission reductions from additional measures. It 

also provides flexibility in analyzing various scenarios and improves accuracy by 

standardizing calculation methodologies. 

To run CEPA, the program requires four data input files. These input files are as 

follows: 

1. Master Measure File - This file contains all the measures proposed in the 

AQMP. There is only one master measure file in the entire CEPA program. 

2. Scenario File - This file is a listing of selected measures to characterize 

emission reductions, and is a subset of the master measure file. For example, it 
Chapter 2 Summaries of Emissions 

III-2-39 

can contain a group of control measures targeting mobile sources only, or a 

group of measures to be implemented by U.S. EPA. 

3. Control Factor File - As previously discussed, this file shows control factor by 

pollutant by SCC/SIC (or CES/CES) pairs for each control measure in a 

specified year. 

4. Baseline Emission File - This file contains projected emission data (tons/day) 

for future years based on the 1997 emissions inventory. There are two types of 

baseline emission data available for CEPA runs. These are the average annual 

day emissions inventory with pollutants VOC, NOx, CO, SOx, and PM10; and 

the planning inventory with pollutants VOC and NOx during summer, and CO 

and NO2 during winter. 

CEPA calculates the remaining emissions at the SCC/SIC level. It can generate many 

types of emission summary reports or electronic files. For example, the program can 

provide composite control factors for on-road mobile sources in sixteen categories used 

in the air quality modeling analysis or composite control factors from all the proposed 

control measures in the scenario file. It can also provide remaining emissions by 

SCC/S1C or CES/CES pairs; by major source category; or by SIC. It can present 

emission reductions by each control measure in the absence of other competing 

measures; or reductions for each control measure following a pre-determined 

implementation sequence. The result of CEPA runs will be presented in Appendix V of 

the 2003 AQMP. 

CARB Emission Data Reports System 

As mentioned in Chapter 1, the entire emissions inventories are compiled and 

maintained by CARB in its statewide emission related information databases named 

California Emission Inventory Development and Reporting System (CEIDARS), and 

California Emission Forecasting and Planning Inventory System (CEFIS). In both 

systems, emissions are traced by CARB’s new coding method called Emission 

Inventory Codes (EIC code). The EIC code is a 14-digit number arranged into four 

fields: major category, source category, materials description and emission subcategory. For example, EIC 210-200-3300-0000 is for dry cleaning using 

perchloroethylene material. 210 indicates this source is under laundering group. 200 

means the source category is dry cleaning. 3300 refers to the material as 

perchloroethylene. 0000 implies, as current, there is no sub-category under this 

particular source. EIC separates emission sources into four major divisions: 

stationary, area-wide, non-anthropogenic and mobile source. This new coding system 

allows flexibility in how sources are selected, sorted and grouped to fit users’ needs. 

The other advantage of this new coding system is that EIC links area sources and 
Appendix III Base and Future Year Emission Inventories 

III-2-40 

point sources together to allow a computer program to automatically reconcile point 

and area source emissions. In this 2003 AQMP, all the emission summary reports are 

based on CARB’s new EIC codes. Because only the anthropogenic sources are 

included in this document, all summary reports in appendices include three major 

divisions. They are stationary, area-wide, and mobile source. This is the first time 

the District is using this new coding system for emission data reports in the AQMP. 

REFERENCES 
References 

III-R-1 

REFERENCES 

ARB, 2002a. EMFAC2002 Release.

ARB, 2002a. California Air Pollution Control Laws. 

ARB, 1996c. Booz Allen & Hamilton Inc., 1993. Emissions From Locomotives in the 

Modeling Region for the South Coast Air Quality Management District. 

Arcadis Geraghty & Miller, 1999. Marine Vessel Emissions Inventory- Update to 1996 

Report : Marine Vessel Emissions Inventory and Control Strategies

Energy and Environmental Analysis, Inc., 1999 South Coast Aircraft Emission 

Inventory: Baseline for 1997

EPA, 1990. AIRS Facility Subsystem Source Classification Codes and Emission Factor 

Listing for Criteria Air Pollutants. 

AVES, 2000. 1997 Gridded Ammonia Emission Inventory Update for the South Coast 

Air Basin

SCAG, 2001. Regional Transportation Plan. 

SCAQMD, 1991. Technical Report III-A; Controlled Emission Projection Algorithms 

(CEPA): Program Documentation.

SCAQMD, 1993. Staff Report: Proposed Rules 2000 to 2015 - Regional Clean Air 

Incentives Market (RECLAIM).

SCAQMD, 1997a. 1994 Air Quality Management Plan.

SCAQMD, 1997b. Appendix III; Current and Future Years Emissions Inventories

SCAQMD, 1999. 1999 Amendments to the 1997 Ozone State Implementation Plan for 

the South Coast Air Basin

SCAQMD 1997. Effectiveness of Regulation XIII – New Source Review. Governing Board 

Meeting February 14, 1997. 

SCAQMD 1998. Report on Effectiveness of Regulation XIII – New Source Review. 

Governing Board Meeting March 13, 1998. 

SCAQMD 1988. Correspondence from Anupom Ganguli of the South Coast Air Quality 

Management District to Mr. Ray Menebroker, of the California Air Resources Board. February 

12, 1998. 
Appendix III: Base and Future Year Emission Inventories 

III-R-2 

SCAQMD 1999. Report of the Effectiveness of Regulation XIII – New Source Review. 

Governing Board Meeting, April 9, 1999. 

SCAQMD 2000. Status Report on Regulation XIII – New Source Review. Governing Board 

Meeting August 18, 2000. 

SCAQMD 2001. Status Report on Regulation XIII – New Source Review. Governing Board 

Meeting November 9, 2001.