California Air Resources Board Development of Emission Inventories for Air Quality Plans Bart E. Croes, P.E. Chief of the Research Division California Air Resources Board Delhi, India November 6-11, 2000

California Air Resources Board 2 Presentation Outline u I.Overview u II.California’s Emission Inventory Program u III.Planning for Emission Inventories

Clean Air Air Quality Monitoring Emission Inventory Air Quality Modeling ControlStrategy Building an Air Quality Plan

California Air Resources Board 4 Emission Inventory “Is a comprehensive listing of the sources of air pollution and an estimate of their emissions within a specific geographic area for a specific time interval.”

California Air Resources Board 5 Inventories can be used to: u Identify sources of pollution u Identify pollutants of concern u Amount, distribution, trends u Identify and track control strategies u Input to air quality modeling u Input to health risk assessment

California Air Resources Board 6 Types of Inventories u Annual average u Seasonal inventories u Forecasted - future estimates u Gridded / Modeling

California Air Resources Board 7 Pollutants: Criteria TOG- total organic gases ROG- reactive organic gases CO- carbon monoxide NO x - oxides of nitrogen SO x - oxides of sulfur PM- particulate matter PM 10 - PM < 10 microns

California Air Resources Board 8 Pollutants: Toxics u Diesel PM u Benzene u 1,3-Butadiene u Formaldehyde u Hexavalent Chromium u Perchloroethlyene u Lead

Stationary Sources u Refineries u Manufacturing u Food processing u Electric utilities u Chemical production

Area-Wide Sources u Farming u Paved & unpaved road dust u Solvents u Consumer products u Open burning

Mobile Sources u Cars u Trucks u Buses u Aircraft u Trains u Ships

Non- anthropogenic u Wildfires u Biogenics u Windblown Dust

California Air Resources Board 13 California’s Emission Inventory Program

California Air Resources Board 14 California’s Emission Inventory Program u Required by State law u Over 30 years of experience u Cooperative effort with other agencies (state, federal, local) u Cooperation with industry groups u Commitment of resources

California Air Resources Board 15 California Process u Local Districts - facility data u State - on-road and off-road emissions u Both share area-wide categories u Other agencies also provide data

California Air Resources Board 16 California’s Inventory u Comprehensive inventory u Data base u Forecasts to 2020 u Criteria and toxics u Over 800 categories of emissions u Over 12,000 stationary sources

California Air Resources Board 17 Inventory Improvements u Ongoing research u Category improvements to support regulations u Intense studies every 3-4 years to support planning process u Published annually u Incorporate new improvements

California Air Resources Board 18 Statewide Changes ROG for 1995

California Air Resources Board 19 Statewide Changes NO x for 1995

Passenger Car Emissions Changes for Southern California Year 2000, by Emissions Model tons/day

California Air Resources Board 21 Consumer Products Southern California, 1997

Southern California NO x, ROG, PM 10 NO x ROG PM 10 Source: 1999 California Almanac of Emissions & Air Quality, ARB

Southern California Trends NO x, ROG, PM 10 NO x ROG PM 10 Source: 1999 California Almanac of Emissions & Air Quality, ARB

Air Quality Improvement versus Growth

California Air Resources Board 25 Resource Commitment u Over 50 people at State level u 35 districts staffs u Millions in research dollars u An inventory for an air quality plan may take 1-3 years and $500k to $1million

California Air Resources Board 26 Lessons Learned u Need for regulatory framework u Inventories take time and resources u Inventory development is a continuous and iterative process u Reduced emission means improved air quality

Planning for the Development of Emission Inventories

California Air Resources Board 28 Developing Emission Inventories u Planning for inventory development u Data collection u Data management and reporting

Type and Scope Emission Inventories for Air Quality Planning Inventory Objectives resolutionsourcespollutantsregion Available Resources MethodologiesMethodologies Responsible Parties Existing Information

California Air Resources Board 30 Selection of Methods u Intended use of inventory u Availability of data u Practicality of method u Priority of category u Time/Resources

California Air Resources Board 31Methodologies u Top down approach u Continuous emission monitors u Source testing u Material balance u Emission factors u Fuel analysis u Surveys u Engineering judgement

California Air Resources Board 32 Estimation Models u BEIS (biogenics) u Landfill Gas Emission Model u TANKS (storage tanks) u MECH (PM emissions form road, ag.) u PM Calc (PM 2.5 emissions) u MOBILE6 / EMFAC2000 u OFFROAD Model

California Air Resources Board 33 Where to Find Information u Emission Inventory Improvement Program (EIIP) –10 volumes of methods u California Air Resources Board –Area Source Manual –Speciation Manuals –CATEF toxic emission factors u U. S. EPA –CHIEF clearinghouse –Fire Database (toxic factors)

Data Collection & Management Reports Annual Average SeasonalForecastedGridded Collect Data  Calculate Emissions  Quality Assurance  Documentation Data Handling System  Reports

Calculate Emissions Process Rate Activity (Activity) Number of Units Units Emission Factor x Emissions per Unit per Unit x Emissions= Total Emissions=

California Air Resources Board 36 Data Collection u Activity data u Emission factors u Facility information u Spatial and temporal u Speciation

California Air Resources Board 37 Data Quality Objectives u Accuracy / uncertainty u Completeness u Representativeness u Comparability u Consistency u Reasonableness

California Air Resources Board 38 Documentation u Methods used u Sources of data u Assumptions u Calculations u Communication

California Air Resources Board 39 Data Management u Needs / capabilities u Expandability / flexibility u Computer system u Ease of use

California Air Resources Board 40 Data Reporting u Annual average u Seasonal u Forecasted u Gridded / modeling

California Air Resources Board 41 Forecasting Emissions u Forecast emissions based on expectations of future economic conditions, population growth, and emission controls u Need a baseline emission inventory, growth factors and control factors

Gridded/Modeling Emissions u Determined by model selection u Spatially and temporally resolved u Hourly emissions by grid cell u Day specific emissions Gridded NO x Emissions

Los Angeles County Gridded ROG Facilities emitting greater than 100 tons/year ROG shown.

California Air Resources Board 44 Resources Needed u Dependent on OBJECTIVES! u Minimum of 18 months - 3 years? u 4-6 people full time? u $500k to $1 million?

Clean Air Air Quality Monitoring Emission Inventory Air Quality Modeling ControlStrategy Building an Air Quality Plan

ConclusionsConclusions u Plan for inventory development u Identify needs u Identify resources u Build on what others have done u Schedule to allow time u Cooperative efforts needed between agencies & businesses

California Air Resources Board 47 ARB Emissions Contact: Linda Murchison, Ph.D Web Site: emisinv/eib.htm California Air Resources Board Contact and Information

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California Air Resources Board Emission Inventory Discussion Group

Type and Scope Emission Inventory Planning Objectivesresolutionsourcespollutantsregion Available Resources MethodologiesMethodologies Responsible Parties Existing Information

Inventories for Air Quality Models

California Air Resources Board 52 Air Quality Models u Use emissions, atmospheric chemistry, and meteorological data to predict pollutant concentrations in the atmosphere

Modeling Input Data u Speciated, gridded emission data u Surface and aloft meteorological measurements u Atmospheric chemistry u Extensive air quality monitoring data

California Air Resources Board 54 Modeling Output Data u Prediction of air quality impacts based on changes in emissions or meteorology u Evaluate mix of emissions reductions to best improve air quality

California Air Resources Board 55 Emissions u Actual –Measured or estimated emissions which most accurately represent the emissions from an emissions unit. For example: The actual rate of emissions is defined in tons per year of any regulated pollutant emitted from a major source over the preceding two years. Actual emissions shall be calculated using the unit's actual operating hours, production rates,and types of materials processed, stored, or combusted during the preceding calendar year or other defined period. For a new emission unit, actual emissions equal the potential to emit of the unit. u Allowable –Permitted emissions levels. Actual should not exceed allowable emissions. u Potential –The maximum physical and operational design capacity to emit a pollutant. Limitations on the physical or operational design capacity, including emissions control devices and limitations on hours of operation, may be considered only if such limitations are incorporated into the applicable Authority to Construct and Permit to Operate. EPA Part 70 regulations define potential to emit as the "maximum capacity of a stationary source to emit any air pollutant under its physical and operational design." In general, this definition means that emissions from a source must be estimated at maximum capacity over 365 days per year.

California Air Resources Board 56 Success in Clean Air u Due to stringent control program u Must account for growth u Stationary Controls –control of industrial sources –consumer products, paints u Mobile Controls –engine standards –retrofit existing engines –clean fuels

California Air Resources Board 57 Databases for Developing Inventories u Microsoft Access Database u Oracle Database u Paradox Database u Dbase Database

California Air Resources Board 58 u SCCs Define and Categorize Emissions Related Data u Identify Emission Processes u 8 Digit Source Classification Codes u Created by U.S. EPA u Over 7100 Valid SCCs Now Available u Important to Assign SCCs Correctly Source Classification Codes (SCC) System

California Air Resources Board 59 Gridded and Modeling Emission Inventories (cont.) u How are emissions spatially allocated? –Point sources - UTM coordinates –Area sources - spatial surrogates (land use or population) –Mobile sources - motor vehicle emission and transportation models

California Air Resources Board 60 Growth Factors u What are growth factors? –Factors based on specific economic profiles for certain industry types –or based on demographic data

California Air Resources Board 61 Control Factors u What are control factors? –Control factors are derived from rules and regulations which impose emission reductions or a technological change on a particular emission process.

California Air Resources Board 62 Emission Controls u Motor Vehicle –catalyst, vapor recovery, OBD, clean fuels u Stationary Sources –scrubbers, cyclones, electrostatic precipitators, bag houses

California Air Resources Board 63 CARB Mobile Source and Fuels Regulations and Programs u New engine emission standards u In-use durability requirements u Retrofit existing engines u Cleaner fuels: gasoline, diesel, natural gas u Promote national and international standards for trucks, ships, and aircraft u New technologies for the future

California Air Resources Board 64 CARB Cleaner Fuels Program u 1992: Eliminated lead from gasoline, limited vapor pressure, required oxygenates in winter to reduce carbon monoxide u 1996: Introduced “cleaner-burning gasoline” to achieve maximum reductions in ozone and toxics u 1999: Phase out MTBE by 2002, reduce sulfur and benzene further

California Air Resources Board 65 CARB NOx Emission Standards for On-Road Trucks g/hp-hr Possible Future Standards NOx aftertreatment-based 75-90% reduction 2007 goal

California Air Resources Board 66 CARB PM Emission Standards For On-Road Trucks g/hp-hr truck bus Possible Future Standards PM trap-based ~90% Reduction 2007 goal

California Air Resources Board 67 Diesel PM and NOx Controls u Cleaner diesel fuel –Very low sulfur enables after-treatment u Exhaust after-treatment –PM traps > 90% efficient –NOx catalysts 50-90% efficiency potential u Alternative fuels: natural gas u New technologies: fuel cells

California Air Resources Board 68 Cleaner Industrial Sources u Best controls on new and existing sources u Controls for NOx, ROG, SOx, CO, toxics u Diesel particulate matter controls to reduce toxics risk

California Air Resources Board 69 Cleaner Consumer Products u CARB has set ROG emission limits for nearly 50 categories of consumer products and 35 categories of aerosol paints and coating products. CARB regulations will reduce emissions by 53 tons per day in Los Angeles CARB regulations will reduce emissions by 53 tons per day in Los Angeles

Relative Toxics Risk for Diesel PM Based on CARB’s ambient monitoring data and estimated diesel PM concentrations Benzene 1,3-Butadiene Chrome VI Carbon Tetrachloride Formaldehyde para-Dichlorobenzene Perchloroethylene Acetaldehyde All Others Diesel PM Contribution to Statewide Cancer Risk

Emissions Inventory Ambient Species (CMB analysis - all species) Slices with lines are secondary PM Does not include secondary PM Rubidoux, 1997 AQMP, App. V, SCAQMD Direct & Secondary PM 2.5 Inventory vs Ambient Air for SCAQMD

California Air Resources Board 72 What is in the Air? u Secondary compounds sometimes significant u Extremely variable –By season –By location –By day San Joaquin Valley PM 2.5 (hypothetical winter day) From ammonia and combustion exhaust primary, direct emissions secondaryemissions

California Air Resources Board 73 PM 10 Inventoried Sources South Coast Air Basin, 1996 Source: ARB 1996 Statewide Inventory 440 tons/day

California Air Resources Board 74 NO x Inventoried Sources South Coast Air Basin, tons/day Source: ARB 1996 Statewide Inventory

California Air Resources Board 75 ROG Inventoried Sources South Coast Air Basin, tons/day Source: ARB 1996 Statewide Inventory

Emission trends NO x Source: 1999 California Almanac of Emissions & Air Quality, ARB

Emission trends ROG Source: 1999 California Almanac of Emissions & Air Quality, ARB

Emission trends PM 10 Source: 1999 California Almanac of Emissions & Air Quality, ARB

Passenger Car Exhaust Changes for Southern California Year 2000, by Emissions Model tons/day

Statewide, 2000 NO x, ROG NO x ROG ROG Old Estimate Revised Estimate