Chapter 2Chapter 2Chapter 2Current Emissions and Air QualityFile 03 Chap 2 Alm2013 p1-22.indd 112/16/2013 10:59:57 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-2This chapter provides statewide information on current emissionsand air quality, relative to the national ambient air quality standards.The first section of this chapter includes a summary table of the statewide emission inventory and the air quality information can be foundin the second section.It should be noted that emission inventories are developed for manypurposes, including SIPs, and for other planning and regulatoryneeds. For this edition of the Almanac, the current emissions datarepresent a calendar year 2012 snapshot with updated mobile sourceestimates from the EMFAC2011 and various off-road models. Alsoincluded are the latest point source estimates provided by districts aswell as inventory improvements from recent SIPs.Emissions DataThe summary table shows emission data by three major source categories: stationary, area-wide, and mobile sources. Emission data fornatural sources are provided in Appendix D. The remaining sectionsof this Chapter provide information on emissions and air quality on astatewide basis. Emissions are presented for NOx, VOC, PM10, PM2.5,DPM, SOx, and NH3.Emissions are reported as annual averages in tons per day (tpd). Formost sources and pollutants that are not seasonal, this describesemissions very well. However, for some pollutants such as PM10andPM2.5, annual averages do not give an accurate indication of theseasonal nature of emissions. Many sources of PM10and PM2.5areseasonal, including wildfires, agricultural processes, and residentialwood combustion. Additionally, many sources of PM10and PM2.5canalso be very localized, and basinwide annual averages do not give anyinformation about these sources.IntroductionAir Quality DataThe air quality section provides an overview of statewide progressmade towards attainment of federal ozone and PM2.5standards. Thediscussion includes maps showing 2011 8-hour ozone design valuesand 2011 maximum 98th percentile 24-hour PM2.5design valuesby air basin. Additionally, exceedance day, design value, and percentabove the standard information has been provided for each pollutant’s nonattainment areas. This information along with the percentabove the standard comparison in Chapter 4 help to give a morecomplete picture of progress in each of these key areas.Additional information is provided for three other pollutants, theseinclude Carbon Monoxide (CO), Nitrogen Dioxide (NO2) and SulfurDioxide (SO2). An indication of “No Data” indicates that not enoughinformation was provided to meet data requirements in order to calculate a value. In some areas “No Data” may mean no data was collected or that the data may have been limited to a certain time of theyear and thus may not meet the minimum data collection threshold.File 03 Chap 2 Alm2013 p1-22.indd 212/16/2013 11:00:14 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-3NOxis a group of gaseous compounds of nitrogen and oxygen, manyof which contribute to the formation of ozone, PM10, and PM2.5.Most NOxemissions are produced by the combustion of fuels.Industrial sources report NOxemissions to local air districts and theARB. Other sources of NOxemissions are estimated by the local airdistricts and the ARB. Mobile sources (including on-road and othermobile) make up about 83 percent of the total statewide NOxemissions. Area-wide sources, which include residential fuel combustionand managed burning and disposal, contribute only a small portionof the total NOxemissions.NOxSources - StatewideVOC Sources - StatewideVOCs are photochemically reactive and contribute to the formationof ozone, as well as PM10and PM2.5. These emissions result primarilyfrom incomplete fuel combustion and the evaporation of chemical solvents and fuels. Mobile sources (including on-road and other mobile)are the largest contributors to statewide VOC emissions. Stationarysources of VOC emissions include processes that use solvents (suchas dry cleaning, degreasing, and coating operations) and petroleumrelated processes (such as petroleum refining and marketing and oiland gas extraction). Area-wide VOC sources include consumer products, pesticides, aerosol and architectural coatings, asphalt paving androofing, farming operations, and other evaporative emissions.Table 2-1NOx Emissions (annual average)Emissions Sourcetons/dayPercentStationary Sources28413%Area-wide Sources754%On-Road Mobile102449%Gasoline Vehicles39519%Diesel Vehicles62930%Other Mobile72334%Gasoline Fuel452%Diesel Fuel61329%Other Fuel653%Total Statewide2106100%Table 2-2VOC Emissions (annual average)Emissions Sourcetons/dayPercentStationary Sources38422%Area-wide Sources60935%On-Road Mobile40323%Gasoline Vehicles37121%Diesel Vehicles332%Other Mobile34220%Gasoline Fuel25915%Diesel Fuel533%Other Fuel292%Total Statewide1739100%File 03 Chap 2 Alm2013 p1-22.indd 312/16/2013 11:00:14 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-4Directly Emitted Particulate Matter (PM10andPM2.5)PM is a mixture of substances that includes elements such as carbonand metals; compounds such as nitrates, sulfates, and organic compounds; and complex mixtures such as diesel exhaust and soil. PM2.5includes fine particles with a diameter of 2.5 microns or smaller andis a subset of PM10. These particles come in many sizes and shapesand can be made up of hundreds of different chemicals. Some particles, known as primary particles are emitted directly from a source,such as construction sites, unpaved roads, fields, smokestacks orfires. Others form in complicated reactions in the atmosphere ofchemicals such as sulfur dioxides and nitrogen oxides that are emitted from power plants, industries and automobiles. These particles,known as secondary particles, make up most of the fine particlepollution in the country.Area-wide sources account for about 65 and 83 percent of the statewide emissions of directly emitted PM2.5and PM10, respectively. Themajor area-wide sources of PM2.5and PM10are fugitive dust, especially dust from unpaved and paved roads, agricultural operations,and construction and demolition. Sources of PM10include crushingor grinding operations, and dust stirred up by vehicles traveling onroads. Sources of PM2.5include all types of combustion, includingmotor vehicles, power plants, residential wood burning, forest fires,agricultural burning, and some industrial processes.Exhaust emissions from mobile sources contribute only a very small portion ofdirectly emitted PM2.5and PM10emissions, but are a major source ofthe VOC and NOxthat form secondary particles.Table 2-3PM2.5Emissions (annual average)Emissions Sourcetons/dayPercentStationary Sources6215%Area-wide Sources27165%On-Road Mobile4310%Gasoline Vehicles215%Diesel Vehicles225%Other Mobile4210%Gasoline Fuel9 2%Diesel Fuel256%Other Fuel8 2%Total Statewide418100%Table 2-4PM10Emissions (annual average)Emissions Sourcetons/dayPercentStationary Sources1238%Area-wide Sources121383%On-Road Mobile785%Gasoline Vehicles483%Diesel Vehicles302%Other Mobile463%Gasoline Fuel101%Diesel Fuel272%Other Fuel9 1%Total Statewide1460100%File 03 Chap 2 Alm2013 p1-22.indd 412/16/2013 11:00:15 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-5Oxides of Sulfur (SOx) are a group of compounds of sulfur and oxygen. Stationary sources account for 49 percent of the emissions ofSOx. Emissions from stationary sources are related to diesel fuel combustion. Other mobile sources, primarily ocean-going vessels, generate about 40 percent of the statewide SOxemissions.SOxSources - StatewideAmmonia is a gaseous compound of nitrogen and hydrogen that caneasily be condensed into a liquid during cold conditions. Ammonia isconsidered a precursor of PM2.5because it can react with NOxin theatmosphere to form ammonium nitrate.Area-wide sources account for 81 percent of the statewide emissionsof ammonia. The major area-wide source of ammonia is livestockwaste. Ammonia emissions from on-road vehicles are produced bythree-way catalyst equipped gasoline vehicles. Ammonia emissionsfrom stationary sources are primarily related to NOxemission controls, the manufacture of a variety of products, and waste disposal.Ammonia emission sources have strong geographic differences. In theSan Joaquin Valley, ammonia emissions are dominated by livestockand other agricultural sources. However, in the South Coast Air Basinammonia emissions from stationary sources and motor vehicles arealso significant contributors.Ammonia Sources - StatewideTable 2-5SOXEmissions (annual average)Emissions Sourcetons/dayPercentStationary Sources5249%Area-wide Sources66%On-Road Mobile55%Gasoline Vehicles4 4%Diesel Vehicles1 1%Other Mobile4240%Gasoline Fuel0 0%Diesel Fuel3836%Other Fuel4 3%Total Statewide105100%Table 2-6NH3Emissions (annual average)Emissions Sourcetons/dayPercentStationary Sources8612%Area-wide Sources57481%On-Road Mobile456%Gasoline Vehicles436%Diesel Vehicles1 0%Other Mobile00%Gasoline Fuel0 0%Diesel Fuel0 0%Other Fuel0 0%Total Statewide706100%File 03 Chap 2 Alm2013 p1-22.indd 512/16/2013 11:00:15 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-6Table 2-7Diesel engines at ports, including ships, cargo handling equipment,locomotives, and trucks, emit a complex mixture of air pollutants,composed of gaseous and solid material. The solid particles in dieselexhaust, which at times may be visible, are known as particulate matter, which includes carbon particles or “soot.” In 1998, ARB identified DPM as a toxic air contaminant based on its potential to causecancer and other health problems.Health risks from DPM are highest in areas of concentrated emissions, such as near ports, rail yards, freeways, or warehouse distribution centers. Exposure to DPM is a health hazard, particularly tochildren whose lungs are still developing, and the elderly who mayhave other serious health problems. DPM is also a large componentof PM pollution in many cities. Table 2-7 shows the source categoriesfor DPM.Diesel PM Sources - StatewideDiesel PM Emissions (annual average)Emissions Sourcetons/dayPercentStationary Sources23%Area-wide Sources00%On-Road Mobile2042%Gasoline Vehicles0 0%Diesel Vehicles2042%Other Mobile2755%Gasoline Fuel0 0%Diesel Fuel2755%Other Fuel0 0%Total Statewide49100%File 03 Chap 2 Alm2013 p1-22.indd 612/16/2013 11:00:15 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-72012 Statewide Emission InventorySummaryTable 2-8*Includes directly emitted particulate matter only.** Natural sources are provided in Appendix D. These summaries do not include emission estimates of wind blown dust - from exposed lake beds from Owens and Mono Lakes. These emissions are estimated to be about23 tons/day of PM10.DivisionEmissions (tons/day, annual average)Major Category VOC NOxSOxPM2.5*PM10*DPM NH3Stationary Sources384 284 5262 123286Fuel Combustion26 211 282226214Waste Disposal384 1 1 2 062Cleaning and Surface Coatings139003300Petroleum Production and Marketing131452200Industrial Processes4964173591010Area-Wide Sources609 756271 1213 0574Solvent Evaporation3540 0 0 0 0155Miscellaneous Processes255 756271 1213 0419Mobile Sources746 1747 4785 124 4745Light Duty Passenger Vehicles139 11721125017Light and Medium Duty Trucks157 2012920023Heavy Duty Trucks64 63112128194Other On-Road447402410Aircraft and Trains37 1574111230Ships, Ocean Going Vessels & C Harbor Craft14 268 381010100Pleasure Crafts981905600Recreational Vehicles34200000Off-Road Equipment123 1810111280Other Off-Road369605660Total Statewide - All Sources**1739 2106 105 418 1460 49 706File 03 Chap 2 Alm2013 p1-22.indd 712/16/2013 11:00:15 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-82012 Statewide Emission Inventoryby Sub-CategoryTable 2-9* Includes directly emitted particulate matter only.DivisionEmissions (tons/day, annual average)Major CategorySub-Category VOC NOxSOxPM2.5*PM10*DPM NH3Stationary Sources (division total)384 284 5262 123286Fuel Combustion (major category total)26 211 282226214- Electric Utilities22155609- Cogeneration21612201- Oil And Gas Production (Combustion)21012200- Petroleum Refining (Combustion)31892201- Manufacturing And Industrial76385601- Food And Agricultural Processing32111110- Service And Commercial54634401- Other (Fuel Combustion)11601200Waste Disposal (major category total)384 1 1 2 062- Sewage Treatment1000000- Landfills121 0 0 1 0 9- Incinerators1310000- Soil Remediation0000000- Other (Waste Disposal)240 0 0 0 052Cleaning And Surface Coatings (major category total)139003300- Laundering2000000- Degreasing34000000- Coatings And Related Process Solvents (sub-category total)58002200- Auto Marine, & Aircraft21000000- Paper & Fabric1000000- Metal, Wood, & Plastic21001100- Other150 0 0 0 0 0File 03 Chap 2 Alm2013 p1-22.indd 812/16/2013 11:00:15 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-92012 Statewide Emission Inventoryby Sub-CategoryTable 2-9 (continued)* Includes directly emitted particulate matter only.DivisionEmissions (tons/day, annual average)Major CategorySub-Category VOC NOxSOxPM2.5*PM10*DPM NH3Stationary Sources (division total) (continued)Cleaning And Surface Coatings (major category) (continued)- Printing18 0 0 0 0 0 0- Adhesives And Sealants 20000000- Other (Cleaning And Surface Coatings)8001100Petroleum Production And Marketing (major category total) 131452200- Oil And Gas Production 36200000- Petroleum Refining 12242200- Petroleum Marketing (sub-category total) 83000000- Fuel Distribution Losses 15000000- Fuel Storage Losses2000000- Vehicle Refueling 38000000- Other28 0 0 0 0 0 0- Other (Petroleum Production And Marketing)0000000Industrial Processes (major category total) 49 64 17 35 91 0 10- Chemical 15221100- Food And Agriculture 18 0 0 3 10 0 0- Mineral Processes 4 53 12 22 64 0 1- Metal Processes0100100- Wood And Paper2 1 0 7 10 0 0- Glass And Related Products0620100- Electronics0000000- Other (Industrial Processes)9101609File 03 Chap 2 Alm2013 p1-22.indd 912/16/2013 11:00:15 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-102012 Statewide Emission Inventoryby Sub-CategoryTable 2-9 (continued)* Includes directly emitted particulate matter only..DivisionEmissions (tons/day, annual average)Major CategorySub-Category VOC NOxSOxPM2.5*PM10*DPM NH3Area-Wide Sources (division total)609 756271 1213 0574Solvent Evaporation (major category total)3540 0 0 0 0155- Consumer Products205000000- Architectural Coatings And Related Process Solvent (sub-category total) 78000000- Architectural Coating66000000- Thinning & Cleanup Solvents12000000- Pesticides/Fertilizers (sub-category total)420 0 0 0 0155- Farm Use390 0 0 0 0155- Commercial Use2000000- Asphalt Paving / Roofing29000000- Other (Solvent Evaporation)-------Miscellaneous Processes (major category total)255 756271 1213 0419- Residential Fuel Combustion (sub-category total)57603555703- Wood Combustion5461505203- Cooking And Space Heating34514400- Other0 100 1 1 0 0- Farming Operations (sub-category total)1460021 1450349- Tilling,Harvesting, & Growing00019 12400- Livestock146003210349File 03 Chap 2 Alm2013 p1-22.indd 1012/16/2013 11:00:15 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-112012 Statewide Emission Inventoryby Sub-CategoryDivisionEmissions (tons/day, annual average)Major CategorySub-Category VOC NOxSOxPM2.5*PM10*DPM NH3Area-Wide Sources (division total) (continued)Miscellaneous Processes (major category) (continued)- Construction And Demolition (sub-category total) 0 0 0 16 164 0 0- Building0 0 0 8 84 0 0- Road Construction Dust0 0 0 8 80 0 0- Paved Road Dust 0 0 0 25 163 0 0- Unpaved Road Dust 0 0 0 27 271 0 0- Fugitive Windblown Dust (sub-category total) 0 0 0 46 320 0 0- Farm Lands 0 0 0 13 77 0 0- Pasture Lands0 0 0 2 13 0 0- Unpaved Roads 0 0 0 30 230 0 0- Fires1001100- Managed Burning And Disposal (sub-category total) 43 15 4 50 57 0 5- Agricultural Burning** 11 7 1 13 14 0 2- Non-Agricultural Burning** 32 7 3 37 43 0 4- Other0000000- Cooking7 0 0 28 33 0 0- Other (Miscellaneous Processes)2 0 0 0 0 0 61Table 2-9 (continued)* Includes directly emitted particulate matter only.** Agricultural burning includes the prescribed burning of prunings andfield crops. Non-agricultural burning includes prescribed burning activities associated with range improvement, forest management, wildlandfire use, and weedabatement.File 03 Chap 2 Alm2013 p1-22.indd 1112/16/2013 11:00:15 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-122012 Statewide Emission Inventoryby Sub-CategoryTable 2-9 (continued)* Includes directly emitted particulate matter only.DivisionEmissions (tons/day, annual average)Major CategorySub-Category VOC NOxSOxPM2.5*PM10*DPM NH3Mobile Sources (division total)746 1747 4785 124 4745On-Road Motor Vehicles (major category total)403 1024 543782045- Light Duty Passenger (sub-category total)139 11721125017- Non-Evaporative65 11621125017- Evaporative74000000- Diesel0200000- Light Duty Trucks(<3750 lbs.) (sub-category total)423302303- Non-Evaporative193202303- Evaporative23000000- Diesel0000000- Light Duty Trucks (>3750 lbs) (sub-category total)597914909- Non-Evaporative277914909- Evaporative32000000- Diesel0000000- Medium Duty Trucks (sub-category total)56901 3 8 011- Non-Evaporative31901 3 8 011- Evaporative25000000- Diesel0000000- Light Heavy Duty Gas Trucks (<10000 lbs) (sub-category total)254401203- Non-Evaporative164401203- Evaporative9000000- Light Heavy Duty Gas Trucks (>10000 lbs) (sub-category total)2400000- Non-Evaporative1400000- Evaporative1000000- Medium Heavy Duty Gas Trucks (sub-category total)6900000- Non-Evaporative4900000- Evaporative2000000File 03 Chap 2 Alm2013 p1-22.indd 1212/16/2013 11:00:15 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-132012 Statewide Emission Inventoryby Sub-CategoryTable 2-9 (continued)* Includes directly emitted particulate matter only.DivisionEmissions (tons/day, annual average)Major CategorySub-Category VOC NOxSOxPM2.5*PM10*DPM NH3Mobile Sources (division total) (continued)On-Road Motor Vehicles (major category) (continued)- Heavy Heavy Duty Gas Trucks (sub-category total)1400000- Non-Evaporative1400000- Evaporative0000000- Light Heavy Duty Diesel Trucks (<10000 lbs)48801210- Light Heavy Duty Diesel Trucks (>10000 lbs)12200100- Medium Heavy Duty Diesel Trucks58804530- Heavy Heavy Duty Diesel Trucks21 37311518151- Motorcycles (sub-category total)36900000- Non-Evaporative26900000- Evaporative11000000- Heavy Duty Diesel Urban Buses13401210- Heavy Duty Gas Urban Buses (sub-category total)1200000- Non-Evaporative1200000- Evaporative0000000- School Buses (sub-category total)1800100- Non-Evaporative1100000- Evaporative0000000- Diesel0700100- Other Gas Buses (sub-category total)1300000- Non-Evaporative1300000- Evaporative0000000- Motor Coach Diesel Buses0700000- All Other Diesel Buses0500000- Motor Homes (sub-category total)2700000- Non-Evaporative1400000- Evaporative1000000- Diesel0300000File 03 Chap 2 Alm2013 p1-22.indd 1312/16/2013 11:00:15 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-14DivisionEmissions (tons/day, annual average)Major CategorySub-Category VOC NOxSOxPM2.5*PM10*DPM NH3Mobile Sources (division total) (continued)Other Mobile Sources (major category total) 342 723 42 42 46 27 0- Aircraft29 55 4 8 9 0 0- Trains8 102 0 3 3 3 0- Ships and Commercial Boats0000000- Ocean Going Vessels (sub-category total) 9 209 377770- Residual Oil0000000- Diesel9 209 37 7 7 7 0- Commercial Harbor Craft 5 5902330- Pleasure Craft (sub-category total) 98 1905600- Non-Evaporative 75 1604600- Evaporative 22000000- Diesel1300000- Off-Road Recreational Vehicles (sub-category total) 34200000- All-Terrain Vehicles 12200000- Motorcycles 17100000- Snowmobiles3000000- Golf Carts, Specialty Carts & Minibikes2000000- Off-Road Equipment (sub-category total) 123 181 0 11 12 8 0- Lawn And Garden Equipment 81 1202200- Non-Evaporative 45701100- Evaporative 35000000- Diesel1500000- Commercial & Industrial Equipment 42 169 0 10 11 8 0- Non-Evaporative 18 1803300- Evaporative9000000- Diesel 16 14007880- Natural Gas 0 1000000- Farm Equipment (sub-category total) 18 9605660- Non-Evaporative2200000- Evaporative2000000- Diesel 14 9505660- Fuel Storage and Handling 18000000Total Statewide - All Sources** 1739 2106 105 418 1460 49 7062012 Statewide Emission Inventoryby Sub-CategoryTable 2-9 (continued)* Includes directly emitted particulate matter only.** Natural sources are provided in Appendix D. These summaries do not include emission estimates of wind blown dust - from exposed lake beds from Owens and Mono Lakes. These emissions are estimated to be about23 tons/day of PM10.File 03 Chap 2 Alm2013 p1-22.indd 1412/16/2013 11:00:16 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-15Ozone concentrations in California have improved greatly over thelast several decades as a result of the implementation of comprehensive control programs for mobile and stationary sources. Comparedwith 1990, ozone concentrations are about 10 to 50 percent lowerthroughout California, with some of the largest decreases occurringin areas with the worst ozone air quality. Additionally, the number ofdays people are exposed to unhealthy ozone levels has dropped by anaverage of over 65 percent among the air basins. A number of areasin the State have been below the federal ozone standards for manyyears, and seven areas that were originally designated as nonattainment for the 1997 federal 8-hour ozone standard of 0.08 ppm nowmeet this standard. In addition, many of these areas also meet, or arevery close to meeting the more health-protective 2008 8-hour ozonestandard of 0.075 ppm. Progress continues in all areas of the State,with the greatest remaining challenge in the South Coast and SanJoaquin Valley.The 2011 data from California’s ozone network are summarized inTable 2-10 and 2-11. Table 2-10 summarizes design values and thenumber of days exceeding the 0.075 ppm 8-hour ozone standard ineach of California’s 15 airbasins. Air basins represent relatively largeareas of the State with similar meteorology and are often geographically linked. Although nine air basins have at least one site with con-ave at least one site with concentrations above the standard, there can be a great deal of variabilitycentrations above the standard, there can be a great deal of variabilityin ozone levels within an air basin. Thein ozone levels within an air basin. Therefore, Table 2-11 provides asummary for the individual regions within these air basins that havebeen designated as nonattainment. Nonattainment areas are portionsof an air basin(s) with unique air pollution characteristics and insome cases can share boundaries with air basins. Of the nonattainment areas 7 of the 16 had concentrations in 2011 which were withinStatewide Ozone - 2011 Air Qualityfive percent of the standard and many areas are expected to meet thestandard by 2015.The highest ozone levels and number of exceedance days are foundin the South Coast and the San Joaquin Valley. SIPs for these tworegions, as well as several other urban areas will be submitted to U.S.EPA in 2016 that will demonstrate how the regions will meet the8-hour ozone standard. More discussion on the SIPs of the five airbasins discussed in this almanac can be found in Chapter 4.File 03 Chap 2 Alm2013 p1-22.indd 1512/16/2013 11:00:16 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-16National 8-Hour Nonattainment Areas: Design Values and 8-Hour Exceedance Days by AreaOzone - 2011 Air Quality Tables8-Hour Design Values and Exceedance Days by Air BasinTable 2-10Table 2-11AIR BASIN2011 8-Hour Design ValueNumber of days in 2011 above the National8-Hour StandardGreat Basin Valleys0.0713Lake County0.0570Lake TahoeN/AN/AMojave Desert0.09795Mountain Counties0.08432North Central Coast0.0700North Coast0.0470Northeast Plateau0.0580Sacramento Valley0.09546Salton Sea0.09359San Diego0.08210San Francisco Bay Area0.0764San Joaquin Valley0.099109South Central Coast0.08311South Coast0.107106AreaDesign ValuesExceedance Days Percent above StandardButte County0.07763%Calaveras County0.07733%Coachella Valley0.0935424%Eastern Kern0.080207%Imperial County0.080157%Mariposa County0.077103%Nevada County (Western part)0.07975%Sacramento Metropolitan Area0.0954527%San Diego County0.082109%San Francisco Bay Area0.07641%San Joaquin Valley0.09910932%San Luis Obispo County (Eastern San Luis Obispo)0.07864%South Coast Air Basin0.10710643%Tuscan Buttes0.07611%Ventura County0.083811%West Mojave Desert0.0979529%File 03 Chap 2 Alm2013 p1-22.indd 1612/16/2013 11:00:16 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-17Due to California’s comprehensive emission control program, PM2.5concentrations in California have improved greatly since monitoringbegan in 1999. Compared with 1999, 24-hour PM2.5concentrationsare about 40 to 50 percent lower throughout California, with someof the largest decreases occurring in areas with the worst PM2.5airquality.A number of areas in the State have been below the federal PM2.5standard for many years, and four areas that were originally designated as nonattainment for the 2006 federal 24-hour PM2.5standardof 35μg/m3now meet this standard. Progress continues in all areas ofthe State, with the greatest remaining challenge in the South Coastand San Joaquin Valley.The 2011 data from California’s PM2.5network are summarized inTables 2-12 and 2-13. Table 2-12 summarizes annual and 24-hourPM2.5design values in each of California’s 15 air basins. Air basinsrepresent relatively large areas of the State with similar meteorology and are often geographically linked. Although three air basinshave at least one site with concentrations above the standard, therecan be a great deal of variability in PM2.5levels within an air basin.Therefore, Table 2-13 provides a summary for the individual regionswithin these air basins that have been designated as nonattainmentfor the 24-hour standard. Nonattainment areas are portions of an airbasin(s) with unique air pollution characteristics and in some casescan share boundaries with air basins. Five of the seven nonattainment areas had 2011 concentrations meeting the standard. Only theSouth Coast and San Joaquin Valley had 2011 concentrations abovethe standard.As mentioned above, the highest PM2.5levels are found in the SouthCoast and San Joaquin Valley, with the highest 24-hour design valueStatewide PM2.5- 2011 Air Qualityand the largest number of exceedance days occurring in the SanJoaquin Valley. SIPs that demonstrate how the regions will attain the24-hour PM2.5standard were submitted to U.S. EPA in 2012 and2013. More discussion on the SIPs for these two areas can be foundin Chapter 4.File 03 Chap 2 Alm2013 p1-22.indd 1712/16/2013 11:00:16 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-18Table 2-12* These statistics and determination of their validity are calculated according to the methods specified in 40 CFR Part 50, Appendix N. Validity is based on the number of measurements available per quarter and therefore, depends on data completeness. Both the 98thpercentile concentration and the average of quarters concentration relate to the national PM2.5standards, while only the average of quarters concentration relates to the State PM2.5standard.** Calexico-Ethel design value is based on incomplete data24-hour data- The table may include data from extreme, exceptional, or unusual concentration events: however, there is a mechanism in place to review for these types of events during the area designation process.Annual average data- Extreme, exceptional, or unusual concentration events do not generally significantly influence the annual average. However, their exclusion can be considered on a case-by-case basis.PM2.5- 2011 Air Quality Tables24-Hour and Annual Average Design Values by Air BasinNational PM2.5Nonattainment Areas: 24-Hour Design Values by AreaTable 2-13AIR BASIN2011 24-Hour Design Valuein micrograms/cubic meter*2011 Annual Average Design Valuein micrograms/cubic meter*Great Basin Valleys36.07.4Lake County7.03.2Mojave Desert**Mountain Counties33.09.4North Central Coast15.06.3North Coast23.06.4Northeast Plateau**Sacramento Valley35.010.1Salton Sea35.0**14.0**San Diego24.011.2San Francisco Bay Area31.09.9San Joaquin Valley62.018.2South Central Coast22.09.3South Coast39.016.2AreaDesign ValuesPercent above StandardImperial35*Meets Standard*Butte County 35 Meets StandardSacramento Metro Area 35 Meets StandardSan Francisco Bay Area Air Basin 31 Meets StandardSan Joaquin Valley Air Basin 62 77%South Coast Air Basin 39 11%Yuba City/Marysville 27 Meets Standard* Calexico-Ethel design value is based on incomplete dataAreas with clean data findings: Butte County, Sacramento, San Francisco Bay Area, and Yuba City/MarysvilleFile 03 Chap 2 Alm2013 p1-22.indd 1812/16/2013 11:00:16 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-19Statewide Carbon Monoxide, Nitrogen Dioxide, Sulfur Dioxide2011 Air QualityThe national CO standard is now attained statewide in California.The requirements for cleaner vehicles and fuels have been primarilyresponsible for the reductions in CO, despite significant increasesin population and the number of vehicle miles traveled each day.8-hour CO design values range from 0.90 to 7.52 ppm, all wellbelow the federal 8-hour CO standard of 9 ppm.California has attained the annual average NO2standard since 1998,with current annual average NO2concentrations ranging from 1 to18 ppb, well below the federal annual average standard of 53 ppb.In the early 1980s, 1-hour NO2concentrations in California were ashigh as 300 ppb, three times the level of the new 1-hour standard.Today, 1-hour NO2design values range from 23 to 75 ppb, withall values meeting the level of the federal 1-hour NO2standard of100 ppb. The current monitoring network provides a robust indicator of regional exposure to NO2. U.S. EPA has also established newmonitoring requirements to measure NO2concentrations near majorroadways in urban areas. Air districts in California are in the processof developing this new network, which will be phased in between2014 and 2017.In 2010, U.S. EPA strengthened the primary NAAQS for SO2to75 ppb. The two existing primary standards were revoked becausethey would not provide additional public health protection given a1-hour standard set at 75 ppb. 1-hour SO2design values range from2 to 17 ppb, and currently, no areas exceed the new lower standard.However, U.S. EPA has stated that the current monitoring networkdoes not adequately characterize short-term SO2concentrations inthe vicinity of SO2emission sources. Therefore, U.S. EPA is expected to require additional evaluation of these sources before makingSO2designations.Nitrogen DioxideSulfur DioxideCarbon MonoxideFile 03 Chap 2 Alm2013 p1-22.indd 1912/16/2013 11:00:16 AMChapter 2Chapter 2ARB Almanac 2013 – Chapter 2: Current Emissions and Air Quality2-20Carbon Monoxide, Nitrogen Dioxide, Sulfur Dioxide - 2011 Air Quality TablesPeak Indicator and Design Values by Air BasinTable 2-14AIR BASIN2011 Carbon Monoxide8-Hour Design Value (ppm)2011 Nitrogen Dioxide1-Hour Design Value (ppb)2011 Sulfur Dioxide1-Hour Design Value (ppb)Great Basin ValleysNo DataNo DataNo DataLake CountyNo DataNo DataNo DataLake TahoeNo DataNo DataNo DataMojave Desert4.25619Mountain CountiesNo DataNo DataNo DataNorth Central Coast0.9033No DataNorth Coast1.61234Northeast PlateauNo DataNo DataNo DataSacramento Valley2.42512Salton Sea7.52648San Diego2.3175No DataSan Francisco Bay Area2.617017San Joaquin Valley2.23598South Central Coast1.81426South Coast3.83727File 03 Chap 2 Alm2013 p1-22.indd 2012/16/2013 11:00:16 AM