Chapter 4Chapter 4Chapter 4Regional Trends and ForecastsFile 05 Chap 4 Alm2013 p1-52.indd 112/16/2013 3:04:22 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-2IntroductionThis chapter provides an in-depth look at emissions and air quality inCalifornia’s five major metropolitan areas (data for individual counties are provided in Appendix B). The emissions data include the latest point source estimates provided by districts as well as inventoryimprovements from recent SIPs. The air quality statistics includevalues reflecting the national ambient air quality standards. Below, wewill briefly discuss some of the statistics used to characterize ozoneand PM air quality in this chapter.In addition to maximum concentrations and number of days abovethe standards, the ozone statistics include the annual 4th high 8-hourconcentration and the design value. The annual 4th high 8-hourconcentration is the annual number that goes into the calculation ofthe national 8-hour design value. We also provide the the maximum1-hour concentration and the national 1-hour design value. Thedesign values are related to the national 8-hour ozone standard andthe national 1-hour ozone standard (revoked). These statistics arereported for the end year of the three-year period. For example, the2011 design value reflects data for the years 2009 through 2011.The design values are concentrations that are compared to the standard for the purpose of determining attainment status. However,values for these statistics that are included in this almanac may notsatisfy data completeness requirements or the boundaries of a nonattainment area, which may differ from county or air basin boundaries.Data conforming to the established design value requirements areavailable for the national 8-hour ozone standard on ARB’s website atwww.arb.ca.gov/airqualitytodayunder “recent year’s ozone air quality.”Historical data are available on the web atwww.arb.ca.gov/adam.Finally, it is important to note that air quality statistics based on asingle year of data (for example, the yearly count of days above thestandard) can fluctuate from year-to-year because of variations inweather. As a result, this almanac compares three-year averages whencharacterizing the percentage increase or decrease in days above thestandard. In this case, the number of exceedance days for 1992 (whichrepresents an average of 1990, 1991, and 1992) is then comparedto the 2011 value (which represents an average of 2009, 2010, and2011), giving a much more stable indicator of long-term progress.File 05 Chap 4 Alm2013 p1-52.indd 212/16/2013 3:04:32 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-3(This page intentionally left blank)File 05 Chap 4 Alm2013 p1-52.indd 312/16/2013 3:04:32 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-4The South Coast Air Basin is California’s largest metropolitan region.The area includes the southern two-thirds of Los Angeles County, allof Orange County, and the western urbanized portions of Riversideand San Bernardino counties. It covers a total of 6,480 square miles,is home to more than 42 percent of California’s population, and generates about 24 percent of the State’s total NOxemissions and about16 percent of the State’s total PM2.5emissions.The South Coast Air Basin generally forms a lowland plain, boundedby the Pacific Ocean on the west and by mountains on the other threesides. In terms of air pollution potential, the warm sunny weatherassociated with a persistent high pressure system is conducive to theformation of ozone, commonly referred to as “smog.” The problemis further aggravated by the surrounding mountains, frequent lowinversion heights, and stagnant air conditions. All of these factors acttogether to trap pollutants in the air basin.Pollutant concentrations in parts of the South Coast Air Basin areamong the highest in the nation. As a result, controlling the contributing emission sources poses a great challenge to State and local airpollution control agencies.South Coast Air BasinIntroduction - Area DescriptionFigure 4-1South Coast Air BasinFile 05 Chap 4 Alm2013 p1-52.indd 412/16/2013 3:04:32 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-5South Coast Air Basin Emissions (tons/day, annual average)Pollutant 2000 2005 2010 2015 2020 2025 2030 2035VOC956678 544 429 400 393 393 391NOX1106 888 603 451 357 289 266 257SOX53 50 19 18 17 17 18 20DPM22 21 12 7 5 4 4 4PM2.588 84 71 67 67 68 70 71PM10179 175 160 155 161 165 170 172NH3123 107 92 96 93 91 93 92Overall, since 2000 the emission levels for the ozone precursors NOxand VOC have been decreasing in the South Coast Air Basin andare projected to continue decreasing through 2035. The decreasesare predominantly due to motor vehicle controls and reductions inevaporative emissions. In the South Coast Air Basin, on-road motorvehicles are the largest contributors to NOx, and VOC emissions.Other mobile sources are also significant contributors to NOxemissions. The emission levels for SOxhave decreased since 2000. Thisis mainly due to the switch from fuel oil to natural gas for electricgeneration and to reduced sulfur content in fuels.South Coast Air BasinEmission Trends and ForecastsFigure 4-2South Coast Air BasinPopulation and VMTBoth population and the daily VMT grew from 2000 to 2010 andare projected to continue to grow at high rates in the South CoastAir Basin from 2010 to 2035. While high growth rates are oftenassociated with corresponding increases in emissions and pollutantconcentrations, aggressive emission control programs in the SouthCoast Air Basin have resulted in emission decreases and a continuingimprovement in air quality.Table 4-1Parameter 1990 1995 2000 2005 2010 2015 2020 2025 2030 2035Population13083594 13745292 14640692 15425626 15735186 16308365 17003779 17624153 18206278 18707348Avg. DailyVMT/1000257490 278813 311684 351680 365620 381013 399639 413000 427819 440283010203040506070801995 2000 2005 2010 2015 2020 2025 2030 2035Percent Growth in Population and VMT from 1990South Coast Air BasinPopulationVMTTable 4-2File 05 Chap 4 Alm2013 p1-52.indd 512/16/2013 3:04:33 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-6South Coast Air BasinOzone Precursor Emission - Trends and ForecastsEmissions of the ozone precursors NOxand VOC in the South CoastAir Basin are generally following the statewide downward trend.Motor vehicle miles traveled in the basin are increasing, but NOxandVOC emissions from on-road vehicles are dropping as more stringentvehicle emission standards have been adopted. These decreases inNOxand VOC emissions are projected to continue between 2010and 2035, as even more stringent motor vehicle standards are impleTable 4-4Table 4-3Figure 4-4Figure 4-3VOC Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources956678 544 429 400 393 393 391Stationary Sources222 123 121 107 115 122 128 133Area-wide Sources188 162 130 119 122 126 130 133On-Road Mobile382 245 178 107 76 63 55 44Gasoline Vehicles367 229 168 101 71 58 49 38Diesel Vehicles15 16 10 5 5 5 5 6OtherMobile165148 114 96 86 82 81 82Gasoline Fuel143 128 100 83 74 70 68 68Diesel Fuel19 17 11 9 8 7 7 8Other Fuel3334455601002003004005006007008002000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)NOXEmission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther Mobile0501001502002503003504004502000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)VOC Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileNOXEmission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources1106888 603 451 357 289 266 257Stationary Sources135 67 62 54 54 55 56 57Area-wide Sources32 28 21 19 18 16 15 14On-Road Mobile707 580 381 249 172 118 102 96Gasoline Vehicles399 246 173 111 73 52 40 31Diesel Vehicles308 334 208 138 99 65 61 65OtherMobile232214 139 128 113 99 93 91Gasoline Fuel27 25 18 15 14 14 14 14Diesel Fuel175 164 101 94 79 66 59 56Other Fuel29 25 20 19 19 20 21 22mented and as newer, lower-emitting vehicles become a larger percentage of the fleet. NOxemissions from electric utilities in the airbasin have declined substantially since 2000, despite a nationwideincrease in emissions from electric utilities in the same time period.These large reductions are primarily due to increased use of naturalgas as the principal fuel for power plants, and control rules that limitNOxemissions.File 05 Chap 4 Alm2013 p1-52.indd 612/16/2013 3:04:34 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-7PM2.5Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035All Sources88 84 71 67 67 68 70 71Stationary Sources17 16 14 14 15 16 17 17Area-wide Sources36 34 33 33 35 35 36 36On-Road Mobile22 21 17 12 11 11 12 12Gasoline Vehicles10 9 9 8 8 8 9 9Diesel Vehicles11 11 8 4 3 3 3 4Other Mobile12 13 8 7 6 5 5 5Gasoline Fuel33333333Diesel Fuel99443222Other Fuel00011111Direct emissions of PM2.5have decreased in the South Coast AirBasin since 2000. Stationary source and area-wide source emissionshave remained relatively flat. The bulk of the decline of PM2.5emissions are from diesel mobile sources.Particulate matter can be directly emitted into the air (primary PM)or, similar to ozone, it can be formed in the atmosphere (secondaryPM) from the reaction of gaseous precursors such as NOx, SOx, VOC,and ammonia. The PM2.5emission inventory includes only directlyemitted particulate emissions.Figure 4-5Table 4-5South Coast Air BasinDirectly Emitted PM2.5Emission - Trends and Forecasts05101520253035402000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)PM2.5Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileFile 05 Chap 4 Alm2013 p1-52.indd 712/16/2013 3:04:35 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-8Diesel PM Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035All Sources22 21 1275444Stationary Sources10000000Area-wide Sources00000000On-Road Mobile11 11 7 3 2 2 2 2Gasoline Vehicles00000000Diesel Vehicles11 11 7 3 2 2 2 2Other Mobile10 10 5 4 3 2 2 2Gasoline Fuel00000000Diesel Fuel10 10 5 4 3 2 2 2Other Fuel00000000Table 4-6Figure 4-6South Coast Air BasinDiesel PM Emission - Trends and ForecastsDiesel PM emissions decreased from 2000 to 2010 primarily asa result of reduced exhaust emissions from diesel mobile sources.These decreases can be attributed to the efforts of ARB’s DieselRisk Reduction Plan. Since its adoption in 2000, this program hasachieved reductions in DPM emissions from on-road and off-roadvehicles as well as stationary and portable diesel-fueled engines. Thishas been accomplished through new regulatory standards for all newdiesel-fueled engines and vehicles along with retrofit requirements(e.g. catalyzed diesel particulate filters) for existing engines and vehicles. Additional reductions are being achieved through improvementsto the quality of diesel fuel by the reduction of sulfur content.Through programs such as the Diesel Risk Reduction Program, emissions from diesel mobile sources are projected to continue to decreasethrough 2035.0246810122000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)Diesel PM Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileFile 05 Chap 4 Alm2013 p1-52.indd 812/16/2013 3:04:36 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-9Ammonia emissions have decreased in the South Coast Air Basinsince 2000. Area-wide source emissions from livestock waste and pesticide usage are expected to remain relatively flat from 2020 through2035. Ammonia emissions from stationary sources, mainly wastedisposal and fuel combustion, are forecasted to increase slightly from2015 to 2035, while on-road mobile source emissions remain flat during the same period.NH3Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035All Sources123 107 92 96 93 91 93 92Stationary Sources26 28 29 40 42 43 44 44Area-wide Sources71 55 44 41 37 35 35 35On-Road Mobile26 24 19 16 14 14 14 14Gasoline Vehicles25 23 18 15 14 13 13 13Diesel Vehicles00001111Other Mobile00000000Gasoline Fuel00000000Diesel Fuel00000000Other Fuel00000000010203040506070802000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)NH3Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileSouth Coast Air BasinAmmonia Emission - Trends and ForecastsFigure 4-7Table 4-7File 05 Chap 4 Alm2013 p1-52.indd 912/16/2013 3:04:36 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-10Figure 4-8South Coast Air BasinOzone Air Quality TrendOzone air quality in the South Coast Air Basin has improved substantially over the last 50 years. During the 1960s, maximum 1-hourconcentrations were above 0.60 ppm. Today, ozone levels rarely reach0.15 ppm, and typical maximum daily values only occasionally reachthe former federal standard of 0.124 ppm. The 2012 8-hour designvalue was 41 percent lower than the 1992 value. The number of daysabove the standards has also declined dramatically, and the trend for1-hour ozone is similar to that for 8-hour. Today, nearly 60 percentof the population lives in areas that meet the 8-hour ozone standard.Although ozone has improved substantially over time, the rate ofprogress has been more modest in recent years. This may be attributable to changes in the mix and reactivity of precursor emissions inthe South Coast. Continuing implementation of emissions controlmeasures will ensure continued progress throughout the Air Basin.The South Coast is designated nonattainment for the 1-hour ozonestandard and the 8-hour ozone standard. ARB and the South CoastAir Quality Management District have developed SIPs to demonstrate how the region will meet these standards. U.S. EPA hasapproved a SIP showing the Basin will meet the 0.08 ppm 8-hourozone standard by 2023. ARB has also submitted a SIP to U.S. EPAdemonstrating the area will meet the 1-hour ozone standard in 2022.These plans call for continuing NOxand VOC reductions needed tomeet the ozone standards. These reductions result from regulationsand incentive programs that lead to cleaner vehicles for on-road and0.000.050.100.150.200.250.300.351992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012

Ozone (ppm)YearMaximum 1-Hour ConcAnnual 4th High 8-Hour Conc1-Hour Design Value8-Hour Design Value1-hr Std8-hr StdSouth Coast Air BasinOzone TrendTable 4-8off-road applications, less polluting consumer products, and industrialand commercial sources. By 2016, the District will submit a new plandemonstrating how the region will meet the 8-hour ozone standard of0.075 ppm by 2032.1The national 1-Hour standard has been revoked. Current and historical 1-Hour data are provided for reference.OZONE (ppm)1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012Annual 4th High 8-Hour0.183 0.172 0.163 0.166 0.154 0.135 0.183 0.133 0.122 0.133 0.131 0.137 0.122 0.130 0.125 0.126 0.120 0.108 0.109 0.113 0.1098-Hour Design Value0.180 0.177 0.171 0.165 0.161 0.148 0.154 0.147 0.146 0.129 0.128 0.131 0.127 0.127 0.121 0.122 0.119 0.118 0.112 0.107 0.106Maximum 1-Hour Concentration 0.300 0.280 0.300 0.256 0.239 0.205 0.244 0.174 0.184 0.190 0.169 0.194 0.163 0.182 0.175 0.171 0.176 0.176 0.143 0.160 0.1471-Hour Design Value10.300 0.300 0.280 0.250 0.231 0.215 0.217 0.211 0.211 0.184 0.169 0.184 0.171 0.173 0.164 0.164 0.164 0.162 0.150 0.143 0.140Days Above Nat. 8-Hour Standard 191 183 164 150 141 155 120 120 126 128 132 133 115 116 114 108 119 113 102 106 111File 05 Chap 4 Alm2013 p1-52.indd 1012/16/2013 3:04:37 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-11South Coast Air BasinOzone Contour Maps: 3-Year Average of National 8-Hour Exceedance Days19922011Another way to look at ozone air quality is to evaluate how widespread the problem is within a region. The maps on this page illustratehow the number of days exceeding the national 8-hour standard havechanged across the South Coast Air Basin over the last two decades.Three-year averages are used to help mitigate the impact of changesin meteorology.Overall, the two maps show a substantial reduction in the number ofexceedance days over the last 20 years. During the 1992 time period,nearly all of the South Coast had more than 50 exceedance days, withmore than 100 days in nearly one-third of the air basin. This is equivalent to more than three months during a year with ozone concentrations above the level of the standard. The coastal areas were cleanerthan the inland areas. However, the entire population of South Coastlived in regions exceeding the 8-hour ozone standardThe 2011 map now shows a large area with less than ten exceedance days. Much of this area currently meets the national standard,including about two-thirds of Orange County and one-third of LosAngeles County, where the majority of the Air Basin population livesand works. Today, this represents nearly 60 percent of the population.The areas with fewer than 50 exceedance days have also grown significantly, while the area with more than 50 days has been reduced.The area with the highest number of exceedance days is now limitedto portions of Riverside and San Bernardino counties.Figure 4-9Figure 4-10File 05 Chap 4 Alm2013 p1-52.indd 1112/16/2013 3:04:37 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-120204060801002001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

PM 2.5 ( μ g/m

3 )Year24-Hour Design ValueAnnual Design Value24-hr StdAnnual StdSouth Coast Air BasinPM2.5TrendFigure 4-11South Coast Air BasinPM2.5Air Quality TrendSimilar to ozone, PM2.5levels in the South Coast have decreasedsignificantly since monitoring began in 1999. Figure 4-11 shows the24-hour and annual average PM2.5design values in the South CoastAir Basin from 1999 through 2011. Overall, the annual averagedesign value has decreased 46 percent since PM2.5monitoring began.The 24-hour PM2.5design value has also declined 49 percent withinthe same period.The South Coast Air Basin is currently designated as nonattainmentfor both the annual and 24-hour PM2.5standards. In 2012, the SouthCoast adopted the2012 Air Quality Management Plan. The plan incorporates a comprehensive strategy aimed at controlling pollution fromall sources, including stationary sources, on-road and off-road mobilesources and area sources. The 2012 plan demonstrates attainment ofthe federal 24-hour PM2.5standard by 2014. In addition, U.S. EPAhas approved a plan showing how the basin will meet the 15μg/m3annual PM2.5standard by 2014. Measures adopted as part of thePM2.5SIP, as well as programs to reduce ozone and diesel PM willcontinue to reduce public exposure to PM2.5in this region. By 2016,the District will submit a new PM2.5plan demonstrating how theregion will meet the revised 12μg/m3annual PM2.5standard.The South Coast Air Basin meets the federal 24-hour PM10standard.Table 4-9PM2.5(μg/m3)1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 201198th Percentile of 24-Hr Conc.85.6 83.0 74.3 66.3 76.6 72.4 58.3 54.4 70.7 47.1 42.9 35.6 40.224-Hour Design Value76.0 73.0 72.0 67.0 65.0 57.0 56.0 53.0 49.0 41.0 39.0Maximum Annual Average30.2 28.3 31.0 27.5 24.8 22.1 20.9 20.8 20.9 18.3 17.2 15.5 15.9Annual Design Value29.8 28.9 27.8 24.8 22.6 20.7 19.6 20.0 18.8 17.0 16.2File 05 Chap 4 Alm2013 p1-52.indd 1212/16/2013 3:04:38 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-13Figure 4-12South Coast Air BasinNitrogen Dioxide Air Quality TrendOver the last 20 years, NO2values have decreased significantly in theSouth Coast Air Basin. The national 1-hour design value for 2011was over 67 percent lower than what it was during 1992.The national annual average standard has not been exceeded since1991. A new national 1-hour standard was adopted by U.S. EPA inJanuary 2010 and is intended to focus on near-road NO2exposure.As a result, a new near-road monitoring network is in the processof being deployed. The South Coast federal 1-hour design value is72 ppb, well below the national 1-hour standard of 100 ppb (98thpercentile).NO2is formed from NOxemissions, which also contribute to ozone.As a result, the majority of the future emission control measures willbe implemented as part of the overall ozone control strategy. Many ofthese control measures will target mobile sources, which account formore than three-quarters of California’s NOxemissions.0501001502002501992 1994 1996 1998 2000 2002 2004 2006 2008 2010

Nitrogen Dioxide (ppb)Year1-Hour Design Value1-hr StdSouth Coast Air BasinNitrogen Dioxide TrendTable 4-10NITROGEN DIOXIDE (ppb)1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011Maximum 1-Hour Concentration300 260 247 239 250 200 255 307 214 251 262 163 157 136 137 108 125 115 118 1101-Hour Design Value223 190 171 168 151 138 127 133 143 151 138 117 111 101 89 84 84 81 79 72Maximum Annual Average51 50 50 46 42 43 43 51 44 41 40 35 34 31 31 31 30 28 26 25File 05 Chap 4 Alm2013 p1-52.indd 1312/16/2013 3:04:39 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-14The San Francisco Bay Area is California’s second largest metropolitanarea. The nine county area comprises all of Alameda, Contra Costa,Marin, Napa, San Francisco, San Mateo, and Santa Clara counties,the southern half of Sonoma County, and the southwestern portionof Solano County. The area is oriented north-south and covers about400 square miles of the area’s total 5,340 square miles.About 19 percent of California’s population resides in the San FranciscoBay Area, and pollution sources in the region account for about 15 percent of the State’s total NOxemissions and about eleven percent ofthe State’s total PM2.5emissions. The climate in the San FranciscoBay Area varies. Along the coast, temperatures are mild year-round.However, as one moves inland, temperatures show larger diurnaland seasonal variations. Overall air quality in the San Francisco BayArea Air Basin is better than inland areas such as the South Coast,San Joaquin Valley, and Sacramento regions. This is due to a morefavorable climate, with cooler temperatures and better ventilation.San Francisco Bay Area Air BasinIntroduction - Area DescriptionSan Francisco Bay Area Air BasinFigure 4-13File 05 Chap 4 Alm2013 p1-52.indd 1412/16/2013 3:04:39 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-15San Francisco Bay Area Air BasinPopulation and VMTCompared with the statewide totals, population and the number ofvehicle miles traveled each day grew steeply until 2000, but haveslowed in recent years and are projected to continue at this slowerrate through 2035. During that 45-year period, the population is projected to increase about 37 percent, from about 5.9 million in 1990to about 8.0 million in 2035. During the same period, the daily VMTis projected to increase 56 percent, from about 135 million miles perday in 1990 to over 210 million miles per day in 2035.The emission levels for the ozone precursors NOxand VOC havebeen trending downward in the San Francisco Bay Area Air Basinsince 2000. On-road motor vehicles are the largest contributors toVOC, and NOxemissions in the air basin. The implementation ofstricter mobile source (both on-road and other) emission standardswill continue to decrease vehicle emissions in this air basin. Controlson stationary source solvent evaporation and fugitive emissions willalso continue to reduce VOC emissions. The emission levels for SOxare also projected to decrease from 2000 to 2015. This is mainly dueto the switch from fuel oil to natural gas for electric generation andto reduced fuel sulfur content.San Francisco Bay Area Air BasinEmission Trends and ForecastsParameter 1990 1995 2000 2005 2010 2015 2020 2025 2030 2035Population 5874273 6182721 6627186 6718351 6982853 7257728 7402393 7590871 7806614 8025820Avg. DailyVMT/1000134997148108 165491 168375 174235 181799 188906 196062 203246 21055401020304050601995 2000 2005 2010 2015 2020 2025 2030 2035Percent Growth in Population and VMT from 1990San Francisco Bay Air BasinPopulationVMTFigure 4-14Table 4-11Table 4-12San Francisco Air Basin Emissions (tons/day, annual average)Pollutant 2000 2005 2010 2015 2020 2025 2030 2035VOC502352 293 236 222 217 217 216NOX591 445 345 272 219 191 181 176SOX71 60 30 24 25 26 28 30DPM10 9 6 3 2 2 2 2PM2.576 60 55 44 44 44 48 48PM10157 133 129 119 121 122 127 129NH333 32 30 31 30 30 31 31File 05 Chap 4 Alm2013 p1-52.indd 1512/16/2013 3:04:39 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-16San Francisco Bay Area Air BasinOzone Precursor Emission - Trends and ForecastsEmissions of ozone precursors have decreased in the San FranciscoBay Area Air Basin since 2000 and are projected to continue declining through 2035. The Bay Area has a significant motor vehiclepopulation, and the implementation of stricter motor vehicle controlshas resulted in significant emissions reductions for NOxand VOC.NOXEmission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035All Sources591 445 345 272 219 191 181 176Stationary Sources87 49 43 40 40 40 41 42Area-wide Sources20 16 15 16 17 18 19 20On-Road Mobile354 267 187 127 84 59 51 46Gasoline Vehicles218 128 86 54 36 26 20 15Diesel Vehicles136 139 101 72 48 33 31 30Other Mobile130112 99 89 79 73 70 68Gasoline Fuel13 12 8 7 7 6 7 7Diesel Fuel92 77 66 55 43 38 35 33Other Fuel25 24 25 27 29 29 29 29VOC Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources502 352 293 236 222 217 217 216Stationary Sources100 66 62 61 65 67 69 72Area-wide Sources97 84 79 72 73 73 75 75On-Road Mobile229 136 99 58 43 37 34 30Gasoline Vehicles221 129 94 54 40 35 31 27Diesel Vehicles77533333Other Mobile7766 53 46 42 40 39 39Gasoline Fuel60 51 40 33 29 27 27 27Diesel Fuel10 8 6 5 4 4 4 4Other Fuel867888880501001502002503003504002000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)NOXEmission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther Mobile0501001502002502000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)VOC Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileFigure 4-15Table 4-13Figure 4-16Table 4-14Stationary source emissions of VOC have declined over the last 15years due to new controls for oil refinery fugitive emissions and newrules for control of VOC from various industrial coatings and solventoperations.File 05 Chap 4 Alm2013 p1-52.indd 1612/16/2013 3:04:40 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-17051015202530354045502000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)PM2.5Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileDirect emissions of PM2.5have declined in the San Francisco BayArea Air Basin between 2000 and 2010 and are projected to increaseslightly through 2035. Emissions from stationary sources declined,while area-wide sources are projected to slightly increase after 2015.This increase in area-wide sources is primarily due to growth in fugitive dust sources. Emissions of directly emitted PM2.5from dieselmotor vehicles have been decreasing since 2000 due to adoption ofmore stringent emission standards; even while population and VMThave increased steadily.Particulate matter can be directly emitted into the air (primary PM)or, similar to ozone, it can be formed in the atmosphere (secondaryPM) from the reaction of gaseous precursors such as NOx, SOx, VOC,and ammonia. The PM2.5emission inventory includes only directlyemitted particulate emissions.San Francisco Bay Area Air BasinDirectly Emitted PM2.5Emission - Trends and ForecastsPM2.5Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources76 60 55 44 44 44 48 48Stationary Sources15 11 11 3 3 3 3 4Area-wide Sources44 34 31 32 32 33 36 36On-Road Mobile10 9 7 6 5 5 6 6Gasoline Vehicles54444444Diesel Vehicles55321122Other Mobile76543333Gasoline Fuel11111111Diesel Fuel54321111Other Fuel10001111Figure 4-17Table 4-15File 05 Chap 4 Alm2013 p1-52.indd 1712/16/2013 3:04:41 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-18Diesel PM Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources109632222Stationary Sources00000000Area-wide Sources00000000On-Road Mobile54311111Gasoline Vehicles00000000Diesel Vehicles54311111Other Mobile54321111Gasoline Fuel00000000Diesel Fuel54321111Other Fuel00000000Table 4-16Figure 4-18San Francisco Bay Area Air BasinDiesel PM Emission - Trends and ForecastsDiesel PMemissions decreased from 2000 to 2010 primarily asa result of reduced exhaust emissions from diesel mobile sources.Emissions from diesel mobile sources are projected to continue todecrease through 2035.01234562000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)Diesel PM Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileFile 05 Chap 4 Alm2013 p1-52.indd 1812/16/2013 3:04:42 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-19Ammonia emissions are forecasted to remain flat in the San FranciscoBay Area Air Basin from 2000 through 2035. Most of the ammoniaemissions are from area-wide sources, particularly from livestockwaste and pesticide usage. Other sources of ammonia emissions arestationary sources, mainly waste disposal and fuel combustion, andon-road mobile sources.NH3Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources33 32 30 31 30 30 31 31Stationary Sources11134444Area-wide Sources19 20 20 20 21 21 21 21On-Road Mobile12 11 9 7 6 6 6 6Gasoline Vehicles12 11 8 7 6 6 6 6Diesel Vehicles00000000Other Mobile00000000Gasoline Fuel00000000Diesel Fuel00000000Other Fuel0000000005101520252000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)NH3Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileSan Francisco Bay Area Air BasinAmmonia Emission - Trends and ForecastsFigure 4-19Table 4-17File 05 Chap 4 Alm2013 p1-52.indd 1912/16/2013 3:04:42 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-200.000.050.100.150.201992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012

Ozone (ppm)YearMaximum 1-Hour ConcAnnual 4th High 8-Hour Conc1-Hour Design Value8-Hour Design Value1-hr Std8-hr StdSan Francisco Bay Area Air BasinOzone TrendSan Francisco Bay Area Air BasinOzone Air Quality TrendOzone concentrations in the San Francisco Bay Area are muchlower than in the South Coast and San Joaquin Valley Air Basins.The 1- and 8-hour design values have declined by an average of nearly17 percent during the last 20 years. The number of days when national standards are exceeded shows a similar trend. The 2012 8-hourdesign value indicates that the area now meets the 2008 federalstandard. Continuing implementation of statewide emissions controlmeasures will ensure continued progress throughout the Air Basin.In September 2010, the Bay Area Air Quality Management Districtadopted theBay Area 2010 Clean Air Plan. The 2010 plan defines acomprehensive multi-pollutant control strategy including 55 controlmeasures to reduce emissions of ozone, PM, air toxics, and greenhouse gases from a wide variety of emission sources.Figure 4-20OZONE (ppm)1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012Annual 4th High 8-Hour0.082 0.082 0.082 0.099 0.099 0.072 0.096 0.093 0.077 0.081 0.094 0.085 0.077 0.075 0.089 0.071 0.087 0.081 0.080 0.075 0.0778-Hour Design Value0.082 0.081 0.082 0.087 0.093 0.090 0.089 0.086 0.087 0.082 0.082 0.086 0.084 0.078 0.080 0.077 0.081 0.078 0.080 0.076 0.073Maximum 1-Hour Concentration 0.130 0.130 0.130 0.155 0.138 0.114 0.147 0.156 0.152 0.134 0.160 0.128 0.113 0.120 0.127 0.120 0.141 0.113 0.150 0.115 0.1021-Hour Design Value10.130 0.120 0.121 0.138 0.138 0.138 0.138 0.139 0.139 0.126 0.124 0.123 0.123 0.113 0.118 0.120 0.121 0.120 0.127 0.109 0.100Days Above Nat. 8-Hour Standard 18 18 13 22 25 5 24 18 9 13 15 12 7 5 17 2 128944Table 4-181The national 1-Hour standard has been revoked. Current and historical 1-Hour data are provided for reference.File 05 Chap 4 Alm2013 p1-52.indd 2012/16/2013 3:04:43 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-21San Francisco Bay Area Air BasinPM2.5Air Quality TrendThe San Francisco Bay Area has seen significant progress in boththe 24-hour and annual average PM2.5design values over the last 13years. The San Francisco Bay Area is in attainment of the nationalannual average PM2.5standard and concentrations have decreased36 percent since 2001. The 24-hour design value has seen the biggestdecline over the past 13 years, decreasing 62 percent.Although the Bay Area is designated as non-attainment for the24-hour national PM2.5standard, recent monitoring data now showsthat the Bay Area meets the 24-hour PM2.5standard. U.S. EPAapproved a “clean data determination” for the 24-hour PM2.5standard for the Bay Area on January 9, 2013.The San Francisco Bay Area Air Basin also attains the national24-hour standard for PM10.0204060801002001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

PM 2.5 ( μ g/m

3 )Year24-Hour Design ValueAnnual Design Value24-hr StdAnnual StdSan Francisco Bay Area Air BasinPM2.5TrendFigure 4-21Table 4-19PM2.5(μg/m3)1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 201198th Percentile of 24-Hr Conc.69.3 63.4 80.0 57.6 37.4 39.8 40.9 36.6 39.2 36.3 33.5 26.8 30.524-Hour Design Value71.0 63.0 47.0 45.0 39.0 39.0 38.0 36.0 36.0 31.0 27.0Maximum Annual Average16.2 13.6 12.8 14.0 11.7 11.6 11.8 10.8 10.7 11.5 10.1 10.5 10.1Annual Design Value14.2 12.7 11.9 11.5 11.7 11.4 11.1 11.0 10.89.19.1File 05 Chap 4 Alm2013 p1-52.indd 2112/16/2013 3:04:43 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-220501001502002501992 1994 1996 1998 2000 2002 2004 2006 2008 2010

Nitrogen Dioxide (ppb)Year1-Hour Design Value1-hr StdSan Francisco Bay Area Air BasinNitrogen Dioxide TrendSan Francisco Bay Area Air BasinNitrogen Dioxide Air Quality TrendThe San Francisco Bay Area has attained the national NO2standardsfor more than 20 years and ambient concentrations continue to bewell below the level of the standard. The 1-hour design value hasdeclined 36 percent since 1992 and design values are below the levelof the 1-hour federal standard of 100 ppb.A new national 1-hour standard was adopted by U.S. EPA inJanuary 2010 and is intended to focus on near-road NO2exposure.As a result, a new near-road monitoring network is in the process ofbeing deployed.NO2is formed from NOxemissions, which also contribute to ozone.As a result, the majority of the future emission control measures willbe implemented as part of the overall ozone control strategy. Many ofthese control measures will target mobile sources, which account formore than three-quarters of California’s NOxemissions.Figure 4-22Table 4-20NITROGEN DIOXIDE (ppb)1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011Maximum 1-Hour Concentration110 120 107 116 108 118 98 128 114 108 80 81 73 74 107 69 80 69 93 931-Hour Design Value110 97 85 90 87 84 78 82 80 81 60 59 57 54 55 57 56 54 62 70Maximum Annual Average25 27 28 27 25 25 25 26 25 24 19 18 17 19 18 17 17 16 16 16File 05 Chap 4 Alm2013 p1-52.indd 2212/16/2013 3:04:43 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-23(This page intentionally left blank)File 05 Chap 4 Alm2013 p1-52.indd 2312/16/2013 3:04:44 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-24The San Joaquin Valley Air Basin (Valley) occupies the southerntwo-thirds of California’s Central Valley. The eight-county area comprises Fresno, Kings, Madera, Merced, San Joaquin, Stanislaus, andTulare counties and the western portion of Kern County. The Valleycovers nearly 23,490 square miles. With very few exceptions, theSan Joaquin Valley is flat, with most of the area lying below 1,000 feetin elevation and most of the population living below 500 feet. TheValley floor slopes downward from east to west, and the San JoaquinRiver winds its way along the western side from south to north.Similar to other inland areas, the San Joaquin Valley has cool wetwinters and hot dry summers. Generally, the temperature increasesand rainfall decreases from north to south.In contrast to other California areas, air quality in the San JoaquinValley is not dominated by emissions from one large urban area.Instead, there are a number of moderately sized urban areas spreadalong the main axis of the Valley. Overall, about 10 percent ofCalifornia’s population lives in the San Joaquin Valley, and pollutionsources in the region account for about 15 percent of the State’s totalNOxemissions and about 18 percent of the State’s total PM2.5emissions.San Joaquin Valley Air BasinIntroduction - Area DescriptionSan Joaquin Valley Air BasinFigure 4-23File 05 Chap 4 Alm2013 p1-52.indd 2412/16/2013 3:04:44 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-25San Joaquin Valley Air Basin Emissions (tons/day, annual average)Pollutant 2000 2005 2010 2015 2020 2025 2030 2035VOC486441 408 344 345 352 356 358NOX567 529 363 272 212 173 159 153SOX27 15 12 10 10 10 11 11DPM16 16 11 6 5 4 3 3PM2.5100 93 77 73 72 72 72 72PM10359 305 284 278 278 276 275 274NH3379 408 434 390 417 444 446 448San Joaquin Valley Air BasinPopulation and VMTThe population and number of vehicle miles traveled each day in theSan Joaquin Valley Air Basin has grown and is projected to continuegrowing at a much faster rate than most other areas of the State. Thepopulation is projected to increase about 125 percent, from about2.6 million in 2000 to nearly six million in 2035. During the sameperiod, the daily VMT is projected to increase by 209 percent, fromover 52 million miles per day in 2000 to over 161 million miles perday in 2035.The emission levels in the San Joaquin Valley Air Basin have beendecreasing since 2000. The decreases are predominantly due to motorvehicle controls and reductions in evaporative and fugitive emissions.On-road motor vehicles, other mobile sources, and stationary sourcesare all significant contributors to NOxemissions. A significant portion of the stationary source VOC emissions is fugitive emissionsfrom the extensive oil and gas production operations in the lowerSan Joaquin Valley. PM10emissions are mostly fugitive dust frompaved and unpaved roads, agricultural operations, and waste burning.The emission levels for SOxhave also decreased since 2000. This ismainly due to the switch from fuel oil to natural gas for electric generation and to reduced fuel sulfur content.San Joaquin Valley Air BasinEmission Trends and ForecastsParameter 1990 1995 2000 2005 2010 2015 2020 2025 2030 2035Population2645311 2972667 3205449 3593550 3848324 4092379 4555564 5018845 5486353 5965229Avg. DailyVMT/100052199 64705 76445 87485 97700 109563 122653 135663 148253 1613100501001502002501995 2000 2005 2010 2015 2020 2025 2030 2035Percent Growth in Population and VMT from 1990San Joaquin Valley Air BasinPopulationVMTFigure 4-24Table 4-21Table 4-22File 05 Chap 4 Alm2013 p1-52.indd 2512/16/2013 3:04:45 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-26San Joaquin Valley Air BasinOzone Precursor Emission - Trends and ForecastsEmissions of the ozone precursors NOxand VOC are projected todecrease in the San Joaquin Valley Air Basin through 2020. WhileNOxcontinues to decline after 2020, VOC increases slightly. Bothstationary source and motor vehicle NOxemissions have beenreduced by the adoption of more stringent emission standards.NOXEmission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources567 529 363 272 212 173 159 153Stationary Sources75 59 41 30 28 28 27 28Area-wide Sources15 16 13 13 13 13 14 14On-Road Mobile324 310 205 138 91 67 65 65Gasoline Vehicles101 65 51 32 22 17 14 12Diesel Vehicles223 245 155 106 69 50 51 54Other Mobile153144 103 91 79 64 53 46Gasoline Fuel55443333Diesel Fuel144 135 95 84 70 55 45 37Other Fuel44335555VOC Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources486 441 408 344 345 352 356 358Stationary Sources112 100 98 96 99 103 107 110Area-wide Sources219 218 212 180 188 196 198 200On-Road Mobile99 70 56 33 26 24 23 21Gasoline Vehicles87 57 48 28 21 18 17 15Diesel Vehicles12 13 9 6 5 6 6 7Other Mobile5653 42 35 32 30 28 27Gasoline Fuel34 32 26 21 19 17 17 16Diesel Fuel19 17 12 10 8 7 6 5Other Fuel444466660501001502002503003502000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)NOXEmission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther Mobile0501001502002502000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)VOC Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileFigure 4-25Table 4-23Figure 4-26Table 4-24Stricter standards have reduced VOC emissions from motor vehiclessince 2000, even though VMT have been increasing. Stationary andarea-wide sources of VOC include petroleum production operationsand the use of solvents. Stricter emission standards and new controlshave reduced the VOC emissions from these sources.File 05 Chap 4 Alm2013 p1-52.indd 2612/16/2013 3:04:45 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-27Direct emissions of PM2.5decreased from 2000 to 2015 and are projected to remain flat after 2015. PM2.5emissions in the San JoaquinValley are dominated by emissions from area-wide sources, primarilyfugitive dust from vehicle travel on unpaved and paved roads, dustfrom farming operations, waste burning, and residential fuel combustion (including wood).Particulate matter can be directly emitted into the air (primary PM)or, similar to ozone, it can be formed in the atmosphere (secondaryPM) from the reaction of gaseous precursors such as NOx, SOx, ROG,and ammonia. The PM2.5emission inventory includes only directlyemitted particulate emissions.San Joaquin Valley Air BasinDirectly Emitted PM2.5Emission - Trends and ForecastsPM2.5Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources100 93 77 73 72 72 72 72Stationary Sources11 10 9 9 9 9 10 10Area-wide Sources70 64 54 54 54 54 54 54On-Road Mobile10 10 7 4 4 5 5 5Gasoline Vehicles22222233Diesel Vehicles78522223OtherMobile98665443Gasoline Fuel11111111Diesel Fuel77543221Other Fuel11112222010203040506070802000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)PM2.5Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileFigure 4-27Table 4-25File 05 Chap 4 Alm2013 p1-52.indd 2712/16/2013 3:04:46 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-28Diesel PM Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources16 16 1165433Stationary Sources11100000Area-wide Sources00000000On-Road Mobile78521112Gasoline Vehicles00000000Diesel Vehicles78521112Other Mobile77543221Gasoline Fuel00000000Diesel Fuel77543221Other Fuel00000000Table 4-26Figure 4-28San Joaquin Valley Air BasinDiesel PM Emission - Trends and ForecastsDiesel PMemissions decreased from 2000 to 2010 primarily asa result of reduced exhaust emissions from diesel mobile sources.Emissions from diesel mobile sources are projected to continue todecrease through 2035.01234567892000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)Diesel PM Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileFile 05 Chap 4 Alm2013 p1-52.indd 2812/16/2013 3:04:47 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-29Ammonia emissions are forecasted to remain relatively constant.About 92 percent of the emissions are from area-wide source emissions from livestock waste and pesticide usage.NH3Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources379 408 434 390 417 444 446 448Stationary Sources17 20 23 26 28 31 34 36Area-wide Sources356 382 405 360 385 409 408 407On-Road Mobile66544455Gasoline Vehicles55544444Diesel Vehicles00000001Other Mobile00000000Gasoline Fuel00000000Diesel Fuel00000000Other Fuel000000000501001502002503003504004502000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)NH3Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileSan Joaquin Valley Air BasinAmmonia Emission - Trends and ForecastsFigure 4-29Table 4-27File 05 Chap 4 Alm2013 p1-52.indd 2912/16/2013 3:04:47 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-300.000.050.100.150.201992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012

Ozone (ppm)YearMaximum 1-Hour ConcAnnual 4th High 8-Hour Conc1-Hour Design Value8-Hour Design Value1-hr Std8-hr StdSan Joaquin Valley Air BasinOzone TrendSan Joaquin Valley Air BasinOzone Air Quality TrendOzone levels in the San Joaquin Valley are among the most severein the State. During the 1980s the Valley averaged nearly 60 federal 1-hour exceedance days per year. However, now the Valley onlyoccasionally exceeds the 1-hour standard. Additionally, 8-hour designvalues have declined an average of nearly 17 percent, while the threeyear average of the national 8-hour exceedance days declined nearly30 percent. Most of this progress has occurred since 2003. Today,nearly 16 percent of the population live in areas that meet the 8-hourozone standard, compared with 20 years ago when the standard wasexceeded throughout the Valley.Similar to the South Coast the San Joaquin Valley is designated nonattainment for the 1-hour and 8-hour ozone standards. ARB and theSan Joaquin Valley Air Pollution Control District have developed SIPsto demonstrate how the region will meet these standards. U.S. EPAhas approved a SIP showing the Valley will meet the 0.08 ppm 8-hourozone standard by 2023. The District has also recently adopted a SIPdemonstrating the area will meet the 1-hour ozone standard by 2017.These plans call for continuing NOx and VOC reductions needed tomeet the ozone standards.These reductions result from regulationsand incentive programs that lead to cleaner vehicles for on-road andoff-road applications, less polluting consumer products, and industrialand commercial sources. By 2016, the District will submit a new planFigure 4-30OZONE (ppm)1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012Annual 4th High 8-Hour0.110 0.117 0.118 0.123 0.126 0.115 0.124 0.109 0.114 0.113 0.119 0.119 0.112 0.108 0.111 0.102 0.112 0.102 0.103 0.102 0.1038-Hour Design Value0.115 0.112 0.111 0.119 0.119 0.115 0.115 0.113 0.111 0.109 0.115 0.115 0.116 0.113 0.110 0.107 0.108 0.105 0.104 0.099 0.098Maximum 1-Hour Concentration 0.160 0.160 0.175 0.173 0.165 0.147 0.169 0.155 0.165 0.149 0.164 0.156 0.155 0.134 0.141 0.138 0.157 0.135 0.140 0.134 0.1351-Hour Design Value10.160 0.160 0.160 0.164 0.165 0.164 0.161 0.161 0.161 0.146 0.151 0.151 0.151 0.149 0.135 0.135 0.140 0.140 0.140 0.130 0.130Days Above Nat. 8-Hour Standard 155 144 137 142 143 138 112 153 144 162 158 160 143 102 120 110 127 98 93 109 105Table 4-281The national 1-Hour standard has been revoked. Current and historical 1-Hour data are provided for reference.demonstrating how the region will meet the 8-hour ozone standard of0.075 ppm by 2032.File 05 Chap 4 Alm2013 p1-52.indd 3012/16/2013 3:04:48 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-31San Joaquin Valley Air BasinOzone Contour Maps: 3-Year Average of National 8-Hour Exceedance Days19922011Another way to look at ozone air quality is to evaluate how widespreadthe problem is within the Air Basin, using data for all sites. The maps onthis page illustrate the reduction in days exceeding the national 8-hourstandard over the last two decades throughout the basin. The use ofthree-year averages helps to mitigate year-to-year changes in meteorology.Similar to the South Coast, the two maps show a substantial reduction inthe number of exceedance days over the last 20 years. During the 1992time period, far more than half of the San Joaquin Valley had between 51and 100 exceedance days. The worst site had 169 days, which is equivalent to nearly six months during a year with ozone concentrations abovethe level of the standard. Areas in the northern San Joaquin Valley werecleaner than areas in the central and southern Valley.The 2011 map shows larger portions of the populated areas of San JoaquinValley which now experience 0 to 5 exceedance days. Much of the rest ofthe Valley experiences an average of 11 to 50 exceedance days per year.Areas with more than 51 exceedance days are generally limited to smallareas in the eastern portion of the central and southern San JoaquinValley. While the extent of these areas is much smaller than during 1992,the areas of poorer ozone air quality overall tend to be the most heavilypopulated. Even though these areas still pose a challenge, the 10 worstsites show an average reduction in exceedance days of more than 43 percent over the last two decades.Figure 4-31Figure 4-32File 05 Chap 4 Alm2013 p1-52.indd 3112/16/2013 3:04:48 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-32San Joaquin Valley Air BasinPM2.5Air Quality Trend0204060801002001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

PM 2.5 ( μ g/m

3 )Year24-Hour Design ValueAnnual Design Value24-hr StdAnnual StdSan Joaquin Valley Air BasinPM2.5TrendWhile the San Joaquin Valley has unique geographical and meteorological challenges, the annual design value for PM2.5shows anoverall downward trend, decreasing 26 percent from 2001 to 2011.The 24-hour PM2.5design value also declined 40 percent during thisperiod, with the most pronounced progress between 2001 and 2004.The San Joaquin Valley Air Basin is currently designated as nonattainment for the annual and 24-hour PM2.5standards. The SanJoaquin Valley adopted their 2012 PM2.5SIP in December 2012 thatshows attainment of the 24-hour PM2.5standard by 2019. The planincorporates a comprehensive strategy aimed at controlling pollutionfrom all sources, including stationary sources, on-road and off-roadmobile sources and area sources. In addition, U.S. EPA has approveda plan showing how the Valley will meet the 15μg/m3annual PM2.5standard in 2014. Measures adopted as part of the PM2.5SIP whichincludes programs to reduce ozone and diesel PM will continue toreduce public exposure to PM2.5in this region. In 2016, the Districtwill submit a new PM2.5plan demonstrating how the region will meetthe revised 12μg/m3annual PM2.5standard.The San Joaquin Valley attains the national 24-hour standard forPM10.Figure 4-33Table 4-29PM2.5(μg/m3)1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 201198th Percentile of 24-Hr Conc.120.0 103.0 96.0 80.4 56.0 61.5 74.9 64.7 73.0 72.3 66.7 56.2 69.524-Hour Design Value104.0 90.0 76.0 62.0 60.0 64.0 69.0 70.0 70.0 65.0 62.0Maximum Annual Average27.6 23.9 22.5 24.1 19.6 18.9 19.8 19.3 22.0 23.5 22.5 17.9 20.4Annual Design Value24.7 23.2 21.8 20.6 19.0 18.9 20.3 21.5 22.6 21.2 18.2File 05 Chap 4 Alm2013 p1-52.indd 3212/16/2013 3:04:49 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-330501001502002501992 1994 1996 1998 2000 2002 2004 2006 2008 2010

Nitrogen Dioxide (ppb)Year1-Hour Design Value1-hr StdSan Joaquin Valley Air BasinNitrogen Dioxide TrendSan Joaquin Valley Air BasinNitrogen Dioxide Air Quality TrendThe San Joaquin Valley has attained the national NO2standardsfor more than 20 years and ambient concentrations continue to bewell below the level of the standard. The 1-hour design value hasdecreased by 41 percent since 1992 and this downward trend isexpected to continue.A new national 1-hour standard was adopted by U.S. EPA in January2010 and is intended to focus on near-road NO2exposure. As aresult, a new near-road monitoring network is in the process of beingdeployed.NO2is formed from NOxemissions, which also contribute to ozone.As a result, the majority of the future emission control measures willbe implemented as part of the overall ozone control strategy. Many ofthese control measures will target mobile sources, which account formore than three-quarters of California’s NOxemissions.Figure 4-34Table 4-30NITROGEN DIOXIDE (ppb)1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011Maximum 1-Hour Concentration190 160 144 119 110 103 112 108 99 115 107 92 83 87 100 101 98 76 82 691-Hour Design Value100 97 95 97 89 84 78 82 81 87 85 83 76 71 68 65 64 61 62 59Maximum Annual Average27 27 24 29 29 24 24 27 24 22 24 23 19 21 21 20 19 18 14 15File 05 Chap 4 Alm2013 p1-52.indd 3312/16/2013 3:04:49 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-34The San Diego Air Basin lies in the southwest corner of Californiaand comprises all of San Diego County. However, the populationand emissions are concentrated mainly in the western portion ofthe County. The Air Basin covers 4,200 square miles, includes abouteight percent of the State’s population, and produces about five percent of the State’s NOxemissions and five percent of the State’sPM2.5emissions. Because of its southerly location and proximityto the ocean, much of the San Diego Air Basin has a relatively mildclimate. Higher temperatures and seasonal variations are experiencedfurther inland.Air quality in the San Diego Air Basin is impacted not only by localemissions, but also by pollutants transported from other areas — inparticular, ozone and ozone precursor emissions transported from theSouth Coast Air Basin and Mexico.San Diego Air BasinIntroduction - Area DescriptionSan Diego Air BasinFigure 4-35File 05 Chap 4 Alm2013 p1-52.indd 3412/16/2013 3:04:50 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-35San Diego Air Basin Emissions (tons/day, annual average)Pollutant 2000 2005 2010 2015 2020 2025 2030 2035VOC198160 139 119 114 111 111 111NOX202 155 120 90 68 56 51 49SOX33211112DPM43211111PM2.526 25 23 19 19 20 20 21PM1076 80 78 73 74 75 76 77NH316 15 15 14 14 14 14 14San Diego Air BasinPopulation and VMTPopulation in the San Diego Air Basin during the 1990-2035 periodis projected to increase by nearly 44 percent, from almost 2.5 millionin 1990 to over 3.6 million in 2035. During this same time period,the number of vehicle miles traveled each day is projected to increaseby 92 percent, from over 57 million miles per day in 1990 to over109 million miles per day in 2035.Emissions of NOxand VOC in the San Diego Air Basin have beenfollowing the declining statewide trends since 2000. These trends arelargely due to motor vehicle controls and reductions in evaporativeemissions. Mobile sources (both on-road and other) are by far thelargest contributors to NOxand VOC emissions in the San Diego AirBasin. The majority of the PM10and PM2.5emissions are from areawide sources.San Diego Air BasinEmission Trends and ForecastsParameter 1990 1995 2000 2005 2010 2015 2020 2025 2030 2035Population2504897 2615201 2828374 2970135 3102745 3225139 3333995 3432537 3530896 3640255Avg. DailyVMT/100057264 63022 72291 77498 82630 86836 90863 97179 103491 10974801020304050607080901001995 2000 2005 2010 2015 2020 2025 2030 2035Percent Growth in Population and VMT from 1990San Diego Air BasinPopulationVMTFigure 4-36Table 4-31Table 4-32File 05 Chap 4 Alm2013 p1-52.indd 3512/16/2013 3:04:51 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-36San Diego Air BasinOzone Precursor Emission - Trends and ForecastsEmissions of the ozone precursors NOxand VOC have been decreasing overall since 2000. These decreases are mostly due to decreasedemissions from motor vehicles, brought about by stricter motorvehicle emission standards. Stationary and area-wide source emisNOxEmission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources202 155 120 90 68 56 51 49Stationary Sources13 7 7 4 4 4 5 5Area-wide Sources33333333On-Road Mobile144 109 79 55 37 27 23 20Gasoline Vehicles90 52 38 25 17 13 10 8Diesel Vehicles53 57 42 30 20 14 13 12Other Mobile4237 32 28 24 22 21 21Gasoline Fuel55444444Diesel Fuel30 25 21 17 13 11 11 10Other Fuel77677777VOC Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources198 160 139 119 114 111 111 111Stationary Sources31 32 33 31 34 35 36 37Area-wide Sources42 38 36 35 36 37 38 39On-Road Mobile82 50 38 24 18 16 14 12Gasoline Vehicles79 48 36 23 17 15 13 11Diesel Vehicles33211111Other Mobile4439 33 28 25 23 23 23Gasoline Fuel36 33 27 22 20 18 18 18Diesel Fuel43221111Other Fuel444444440204060801001201401602000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)NOxEmission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther Mobile01020304050607080902000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)VOC Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileFigure 4-37Table 4-33Figure 4-38Table 4-34sions of VOC have remained mostly unchanged over the last 35 years,with stricter emission standards offsetting industrial and populationgrowth.File 05 Chap 4 Alm2013 p1-52.indd 3612/16/2013 3:04:51 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-37Direct emissions of PM2.5decreased steadily in the San DiegoAir Basin between 2000 and 2010 and are projected to increaseslightly after 2020.Particulate matter can be directly emitted into the air (primary PM)or, similar to ozone, it can be formed in the atmosphere (secondaryPM) from the reaction of gaseous precursors such as NOx, SOx, VOC,and ammonia. The PM2.5emission inventory includes only directlyemitted particulate emissions.San Diego Air BasinDirectly Emitted PM2.5Emission - Trends and ForecastsPM2.5Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources26 25 23 19 19 20 20 21Stationary Sources66533333Area-wide Sources11 11 11 11 11 11 12 12On-Road Mobile44332333Gasoline Vehicles22222222Diesel Vehicles22111111Other Mobile44433333Gasoline Fuel11111111Diesel Fuel21110000Other Fuel22222222024681012142000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)PM2.5Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileFigure 4-39Table 4-35File 05 Chap 4 Alm2013 p1-52.indd 3712/16/2013 3:04:52 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-38Diesel PM Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources43211111StationarySources00000000Area-wide Sources00000000On-Road Mobile22100000Gasoline Vehicles00000000Diesel Vehicles22100000Other Mobile21110000Gasoline Fuel00000000Diesel Fuel21110000Other Fuel00000000Table 4-36Figure 4-40San Diego Air BasinDiesel PM Emission - Trends and ForecastsDiesel PMemissions decreased from 2000 to 2010 primarily asa result of reduced exhaust emissions from diesel mobile sources.Emissions from diesel mobile sources are projected to continue todecrease through 2035.00.20.40.60.811.21.41.61.822000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)Diesel PM Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileFile 05 Chap 4 Alm2013 p1-52.indd 3812/16/2013 3:04:53 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-39Ammonia emissions remain fairly flat from 2000 through 2035 in theSan Diego Air Basin. The majority of the emissions are from areawide sources such as livestock waste and pesticide usage. Most of theremaining ammonia emissions are from on-road mobile sources.NH3Emission Trends (tons/day, annual average)Emission Source 2000 2005 2010 2015 2020 2025 2030 2035AllSources16 15 15 14 14 14 14 14Stationary Sources11111111Area-wide Sources9 9 9 9 9 9 9 10On-Road Mobile65443333Gasoline Vehicles65443333Diesel Vehicles00000000Other Mobile00000000Gasoline Fuel00000000Diesel Fuel00000000Other Fuel000000000246810122000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)NH3Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileSan Diego Air BasinAmmonia Emission - Trends and ForecastsFigure 4-41Table 4-37File 05 Chap 4 Alm2013 p1-52.indd 3912/16/2013 3:04:54 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-400.000.050.100.150.201992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012

Ozone (ppm)YearMaximum 1-Hour ConcAnnual 4th High 8-Hour Conc1-Hour Design Value8-Hour Design Value1-hr Std8-hr StdSan Diego Air BasinOzone TrendSan Diego Air BasinOzone Air Quality TrendBoth the design value and the number of days above the nationalozone standard have decreased substantially over the last 20 years.The 8-hour ozone design value shows an overall decline of 31 percentfrom 1992 to 2012. There were 105 national 8-hour standard exceedance days during 1992, compared with 10 during 2012, representinga decrease of 88 percent in the three-year average of the national8-hour exceedance days. Today, 97 percent of thepopulation live inareas meeting the standard.San Diego County is nonattainment for the 0.075 ppm 8-hour ozonestandard. The region met the level of the previous 0.08 ppm 8-hourozone standard in 2011 resulting in the U.S. EPA issuing a CleanData Finding and redesignating San Diego to attainment for the0.08 ppm 8-hour ozone standard on July 5, 2013. Current ARB andlocal programs will provide the continuing reductions in NOxandVOCs required to bring San Diego County into attainment of the0.075 ppm standard.Figure 4-42OZONE (ppm)1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012Annual 4th High 8-Hour0.110 0.112 0.107 0.107 0.099 0.093 0.114 0.092 0.095 0.096 0.096 0.089 0.083 0.087 0.094 0.086 0.098 0.085 0.081 0.082 0.0818-Hour Design Value0.118 0.112 0.109 0.108 0.104 0.099 0.102 0.099 0.100 0.094 0.095 0.093 0.089 0.086 0.088 0.089 0.092 0.089 0.088 0.082 0.081Maximum 1-Hour Concentration 0.170 0.187 0.147 0.162 0.138 0.136 0.164 0.124 0.124 0.141 0.121 0.125 0.129 0.113 0.121 0.134 0.139 0.119 0.107 0.114 0.1011-Hour Design Value10.170 0.154 0.150 0.146 0.141 0.137 0.133 0.131 0.130 0.118 0.118 0.118 0.115 0.112 0.113 0.113 0.121 0.119 0.116 0.105 0.101Days Above Nat. 8-Hour Standard 105 91 90 94 64 43 58 44 46 43 31 38 23 24 38 27 35 24 14 10 10Table 4-381The national 1-Hour standard has been revoked. Current and historical 1-Hour data are provided for reference.File 05 Chap 4 Alm2013 p1-52.indd 4012/16/2013 3:04:55 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-41San Diego Air BasinPM2.5Air Quality TrendThe San Diego Air Basin currently meets both the national annualPM2.5standard of 15μg/m3and the 24-hour PM2.5standard of35μg/m3. San Diego Air Basin has seen a 42 percent decrease in the24-hour PM2.5design value since 2001. San Diego’s annual designvalue has also decreased 26 percent since 2001.The San Diego Air Basin also attains the national 24-hour standardfor PM10.0204060801002001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

PM 2.5 ( μ g/m

3 )Year24-Hour Design ValueAnnual Design Value24-hr StdAnnual StdSan Diego Air BasinPM2.5TrendFigure 4-43Table 4-39PM2.5(μg/m3)1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 201198th Percentile of 24-Hr Conc.45.1 48.7 40.8 39.3 46.9 37.4 30.2 30.8 37.7 30.2 25.2 25.2 27.424-Hour Design Value45.0 43.0 41.0 39.0 36.0 32.0 30.0 32.0 31.0 26.0 26.0Maximum Annual Average18.0 15.8 17.7 16.0 15.5 14.1 11.8 13.1 13.3 13.7 13.5 12.3 12.4Annual Design Value17.1 16.4 15.9 14.9 12.8 12.1 11.9 13.2 12.8 12.1 12.7File 05 Chap 4 Alm2013 p1-52.indd 4112/16/2013 3:04:55 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-42San Diego Air BasinNitrogen Dioxide Air Quality TrendThe San Diego Air Basin attains the national NO2standard. Since1990, ambient concentrations have been well below the levels of thenational 1-hour and annual average standards. Data show that the1-hour design value decreased nearly 38 percent from 1992 to 2011.A new national 1-hour standard was adopted by U.S. EPA in January2010 and is intended to focus on near-road NO2exposure. As aresult, a new near-road monitoring network is in the process of beingdeployed.Because NOxemissions contribute to ozone, as well as to NO2, manyof the ozone control measures help reduce ambient NO2concentrations. Furthermore, NOxemission controls are a critical part of theozone control strategy. As a result, these controls should ensure continued attainment of the national NO2standard.0501001502002501992 1994 1996 1998 2000 2002 2004 2006 2008 2010

Nitrogen Dioxide (ppb)Year1-Hour Design Value1-hr StdSan Diego Air BasinNitrogen Dioxide TrendFigure 4-44Table 4-40NITROGEN DIOXIDE (ppb)1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011Maximum 1-Hour Concentration190 130 157 140 124 142 132 172 117 148 126 148 125 109 97 101 123 91 91 1001-Hour Design Value120 109 104 99 95 94 88 91 88 96 91 95 88 71 86 86 88 85 82 75Maximum Annual Average27 23 24 26 22 24 23 26 24 22 22 21 23 24 24 22 24 21 21 20File 05 Chap 4 Alm2013 p1-52.indd 4212/16/2013 3:04:55 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-43(This page intentionally left blank)File 05 Chap 4 Alm2013 p1-52.indd 4312/16/2013 3:04:55 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-44Located in the northern portion of the Central Valley, the SacramentoMetropolitan Area is home to California’s capital. This area includesthe southern part of the Sacramento Valley Air Basin as well as thewestern portion of El Dorado County and the western and centralportions of Placer County. The Sacramento Metropolitan Area occupies 5,602 square miles and has a population of more than two million people, or just over six percent of the State’s population. Thisarea produces about five percent of the State’s NOxemissions andsix percent of the State’s PM2.5emissions.Because of its inland location, the climate of the SacramentoMetropolitan Area is more extreme than that of the San FranciscoBay Area or South Coast air basins. The winters are generally cooland wet, while the summers are hot and dry.Emissions from the urbanized portion (Sacramento, Yolo, Solano,and Placer Counties) dominate the emission inventory for theSacramento Metropolitan Area, and on-road motor vehicles are theprimary source of emissions.Sacramento Metropolitan AreaIntroduction - Area DescriptionSacramento Metropolitan AreaFigure 4-45File 05 Chap 4 Alm2013 p1-52.indd 4412/16/2013 3:04:55 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-45Sacramento Metropolitan AreaPopulation and VMTBetween 1990 and 2035, population in the Sacramento MetropolitanArea is projected to grow at a higher rate than the statewide average-a90 percent increase, compared with a 54 percent increase statewide.Population is projected to grow from 1.6 million in 1990 to almost3.1 million in 2035. During this same period, the increase in the number of vehicle miles traveled each day is projected to be higher thanthe overall statewide value: a 157 percent increase in the SacramentoMetropolitan Area. VMT are projected to increase from about 29 million miles in 1990 to over 75 million miles in 2035.The emission levels in the Sacramento Metropolitan Area are trending downward from 2000 to 2035 for NOxand VOC. The decreasesin NOxand VOC are largely due to motor vehicle controls andreductions in evaporative emissions. Mobile sources are by far thelargest contributors to NOxand VOC emissions in the SacramentoMetropolitan Area. PM2.5emissions decrease slightly from 2000 to2035 while PM10emissions remain constant The emission levels forSOxare also fairly flat from 2000 to 2035.Sacramento Metropolitan AreaEmission Trends and ForecastsSacramento Metropolitan Area Emissions (tons/day, annual average)Pollutant 2000 2005 2010 2015 2020 2025 2030 2035VOC158126 110 99 94 93 95 94NOX187 165 118 96 74 62 57 54SOX33222222DPM44211111PM2.532 28 24 25 25 25 26 27PM1086 83 80 83 84 84 86 87NH328 28 28 28 28 28 28 28Parameter 1990 1995 2000 2005 2010 2015 2020 2025 2030 2035Population1614624 1771449 1964285 2201002 2336097 2432108 2565083 2706127 2870371 3062405Avg. DailyVMT/100029177 33472 37187 40080 45628 51621 57720 63493 69350 750570204060801001201401601801995 2000 2005 2010 2015 2020 2025 2030 2035Percent Growth in Population and VMT from 1990Sacramento Metropolitan AreaPopulationVMTFigure 4-46Table 4-41Table 4-42* Note: VMT is estimated at the county, air basin, and air district level. Since the Sacramento Metropolitan Ozone Non-attainmentarea includes sub-county areas, the above VMT and population estimates include a small portion of Sutter county which fallsoutside the Sacramento Metropolitan Ozone Non-attainment areaFile 05 Chap 4 Alm2013 p1-52.indd 4512/16/2013 3:04:56 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-46Sacramento Metropolitan AreaOzone Precursor Emission - Trends and ForecastsEmissions of NOxdecreased from 2000 to 2010 and are projectedto continue decreasing from 2010 to 2035. On-road motor vehiclesand other mobile sources are by far the largest contributors to NOxemissions. More stringent mobile source emission standards andNOXEmission Trends (tons/day, annual average)Emission Sources 2000 2005 2010 2015 2020 2025 2030 2035AllSources187 165 118 96 74 62 57 54Stationary Sources16 13 12 13 12 13 13 13Area-wide Sources65566666On-Road Mobile118 103 72 50 34 24 21 19Gasoline Vehicles68 42 31 20 14 10 8 7Diesel Vehicles51 61 41 30 19 14 13 12Other Mobile4743 30 27 23 19 17 15Gasoline Fuel33333333Diesel Fuel42 37 24 21 17 14 11 10Other Fuel32233333VOC Emission Trends (tons/day, annual average)Emission Sources 2000 2005 2010 2015 2020 2025 2030 2035AllSources158 126 110 99 94 93 95 94Stationary Sources20 19 21 24 25 26 27 28Area-wide Sources45 38 35 38 39 40 42 43On-Road Mobile62 40 31 18 14 12 11 9Gasoline Vehicles59 36 29 17 13 11 9 8Diesel Vehicles33211111Other Mobile3129 23 19 16 15 14 14Gasoline Fuel26 24 20 16 14 13 12 12Diesel Fuel54322111Other Fuel111111110204060801001201402000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)NOXEmission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther Mobile0102030405060702000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)VOC Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileFigure 4-47Table 4-43Figure 4-48Table 4-44cleaner burning fuels have largely contributed to the decline in NOxemissions. VOC emissions have continued decreasing due to morestringent motor vehicle standards and new rules for control of VOCfrom various industrial coating and solvent operations.File 05 Chap 4 Alm2013 p1-52.indd 4612/16/2013 3:04:57 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-47Direct emissions of PM2.5have steadily declined in the SacramentoMetropolitan Area between 2000 and 2010 and then are projectedto increase very slightly through 2035. Emissions are dominated bycontributions from area-wide sources, primarily fugitive dust frompaved and unpaved roads, fugitive dust from construction and demolition, particulates from residential fuel combustion (including wood),and waste burning. Emissions of directly emitted PM2.5from mobilesources and stationary sources in the Sacramento Metropolitan Areahave remained relatively steady.Particulate matter can be directly emitted into the air (primary PM)or, similar to ozone, it can be formed in the atmosphere (secondaryPM) from the reaction of gaseous precursors such as NOx, SOx, ROG,and ammonia. The PM2.5emission inventory includes only directlyemitted particulate emissions.Sacramento Metropolitan AreaDirectly Emitted PM2.5Emission - Trends and ForecastsPM2.5Emission Trends (tons/day, annual average)Emission Sources 2000 2005 2010 2015 2020 2025 2030 2035AllSources32 28 24 25 25 25 26 27Stationary Sources54344455Area-wide Sources22 18 17 17 17 17 19 19On-Road Mobile33322222Gasoline Vehicles21111222Diesel Vehicles22111111Other Mobile33221111Gasoline Fuel11111000Diesel Fuel22111000Other Fuel0000000005101520252000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)PM2.5Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileFigure 4-49Table 4-45File 05 Chap 4 Alm2013 p1-52.indd 4712/16/2013 3:04:59 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-48Diesel PM Emission Trends (tons/day, annual average)Emission Sources 2000 2005 2010 2015 2020 2025 2030 2035All Sources44211111Stationary Sources00000000Area-wide Sources00000000On-Road Mobile22110000Gasoline Vehicles00000000Diesel Vehicles22110000OtherMobile22111000Gasoline Fuel00000000Diesel Fuel22111000Other Fuel00000000Table 4-46Figure 4-50Sacramento Metropolitan AreaDiesel PM Emission - Trends and ForecastsDiesel PMemissions decreased from 2000 to 2010 primarily asa result of reduced exhaust emissions from diesel mobile sources.Emissions from diesel mobile sources are projected to continue todecrease through 2035.00.511.522.52000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)Diesel PM Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileFile 05 Chap 4 Alm2013 p1-52.indd 4812/16/2013 3:04:59 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-49Ammonia emissions are projected to remain fairly constant in theSacramento Metropolitan Area. These emissions are dominated byarea-wide sources such as livestock waste and pesticide usage. Othercontributors of ammonia emissions are stationary sources and onroad mobile source.NH3Emission Trends (tons/day, annual average)Emission Sources 2000 2005 2010 2015 2020 2025 2030 2035AllSources28 28 28 28 28 28 28 28Stationary Sources12333333Area-wide Sources23 22 22 22 22 22 22 22On-Road Mobile44332222Gasoline Vehicles44332222Diesel Vehicles00000000Other Mobile00000000Gasoline Fuel00000000Diesel Fuel00000000Other Fuel0000000005101520252000 2005 2010 2015 2020 2025 2030 2035

Annual Average (tons/day)NH3Emission TrendsStationary SourcesArea-wide SourcesOn-Road MobileOther MobileSacramento Metropolitan AreaAmmonia Emission - Trends and ForecastsFigure 4-51Table 4-47File 05 Chap 4 Alm2013 p1-52.indd 4912/16/2013 3:05:00 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-500.000.050.100.150.201992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012

Ozone (ppm)YearMaximum 1-Hour ConcAnnual 4th High 8-Hour Conc1-Hour Design Value8-Hour Design Value1-hr Std8-hr StdSacramento Metropolitan AreaOzone TrendSacramento Metropolitan AreaOzone Air Quality TrendSince 1992, the 8-hour design value decreased approximately 10 percent. Although the trend is more variable for the number of daysabove the national standards. The three-year average of the national8-hour exceedance days has declined nearly 45 percent since 1992.Additionally, the population living in areas below the standard hasincreased from five percent in 1992 to 36 percent in 2011.In March 2009, ARB approved the2009 Sacramento Regional 8-HourOzone Attainment and Reasonable Further Progress Plan. This plan setsout a strategy for attaining the 1997 federal 8-hour ozone standard inthe Sacramento Nonattainment Area by 2018. By 2016, the Districtwill submit a new plan demonstrating how the region will meet the8-hour ozone standard of 0.075 ppm by 2032. U.S. EPA finalizeda “clean data determination” for the 1-hour ozone standard for theSacramento Metropolitan Area on October 3, 2012.Figure 4-52OZONE (ppm)1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012Annual 4th High 8-Hour0.111 0.103 0.106 0.111 0.104 0.092 0.115 0.106 0.103 0.105 0.111 0.106 0.092 0.102 0.105 0.093 0.114 0.096 0.096 0.094 0.0978-Hour Design Value0.105 0.110 0.104 0.106 0.106 0.099 0.103 0.103 0.107 0.104 0.106 0.107 0.102 0.097 0.097 0.098 0.102 0.100 0.102 0.095 0.095Maximum 1-Hour Concentration 0.170 0.150 0.145 0.156 0.157 0.145 0.163 0.160 0.138 0.148 0.156 0.145 0.118 0.134 0.143 0.138 0.166 0.122 0.124 0.123 0.1251-Hour Design Value10.160 0.150 0.142 0.145 0.145 0.145 0.149 0.149 0.149 0.144 0.148 0.148 0.145 0.139 0.134 0.134 0.139 0.132 0.132 0.122 0.123Days Above Nat. 8-Hour Standard 90 48 73 64 76 45 60 80 61 73 86 79 61 53 74 38 56 42 23 45 49Table 4-481The national 1-Hour standard has been revoked. Current and historical 1-Hour data are provided for reference.File 05 Chap 4 Alm2013 p1-52.indd 5012/16/2013 3:05:00 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-51Sacramento Metropolitan AreaPM2.5Air Quality TrendThe Sacramento Metropolitan Area has seen significant progress inboth the 24-hour and annual average PM2.5design values over thelast 13 years. The Sacramento Metropolitan Area is in attainment ofthe national annual average PM2.5standard and concentrations havedecreased 20 percent since 2001. The 24-hour design value has seenthe biggest decline over the past 14 years, decreasing 51 percent.Although the Sacramento Metropolitan Area is designated as nonattainment for the 24-hour national PM2.5standard, recent monitoring data now shows that the Sacramento Metropolitan Area meets the24-hour national PM2.5standard. U.S. EPA finalized a “clean datadetermination” for the 24-hour PM2.5standard for the SacramentoMetropolitan Area on July 15, 2013.The Sacramento Metropolitan Area also currently attains the national24-hour standard for PM10.0204060801002001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

PM 2.5 ( μ g/m

3 )Year24-Hour Design ValueAnnual Design Value24-hr StdAnnual StdSacramento Metropolitan AreaPM2.5TrendFigure 4-53Table 4-49PM2.5(μg/m3)1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 201198th Percentile of 24-Hr Conc.96 84 81 53 63 43.0 42.0 49.0 55.0 53.0 54.9 38.7 27.3 45.124-Hour Design Value72 68 60 51.0 49.0 45.0 49.0 52.0 54.0 49.0 40.0 35.0Maximum Annual Average19.9 12.3 11.9 14.3 12.3 11.5 11.5 13.1 12.3 13.2 10.7 8.8 10.5Annual Design Value12.5 12.4 11.7 10.8 11.8 12.0 12.3 12.9 12.1 10.9 10.0File 05 Chap 4 Alm2013 p1-52.indd 5112/16/2013 3:05:01 PMChapter 4Chapter 4ARB Almanac 2013 – Chapter 4: Regional Trends and Forecasts4-520501001502002501992 1994 1996 1998 2000 2002 2004 2006 2008 2010

Nitrogen Dioxide (ppb)Year1-Hour Design Value1-hr StdSacramento Metropolitan AreaNitrogen Dioxide TrendSacramento Metropolitan AreaNitrogen Dioxide Air Quality TrendThe Sacramento Metropolitan Area has attained the national NO2standard for more than 20 years. The 2011 1-hour design valuehas declined by 43 percent from 1992 levels. The SacramentoMetropolitan Area shows more variability in maximum 1-hour concentrations than other areas of the State. This variability may bedue to changes in emission sources and may also reflect year-to-yearchanges in meteorology. However, ambient concentrations are wellbelow the level of both standards.A new national 1-hour standard was adopted by U.S. EPA in January2010 and is intended to focus on near-road NO2exposure. As aresult, a new near-road monitoring network is in the process of beingdeployed.NO2is formed from NOxemissions, which also contribute to ozone.As a result, the majority of the future emission control measures willbe implemented as part of the overall ozone control strategy. Many ofthese control measures will target mobile sources, which account formore than three-quarters of California’s NOxemissions.Figure 4-54Table 4-50NITROGEN DIOXIDE (ppb)1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011Maximum 1-Hour Concentration190 120 111 99 145 92 101 110 86 172 90 102 146 79 97 127 115 68 95 661-Hour Design Value90 90 83 80 78 75 72 71 71 71 67 67 67 63 58 57 57 56 54 51Maximum Annual Average21 22 22 22 22 19 21 21 19 19 20 18 17 16 16 15 15 13 12 13File 05 Chap 4 Alm2013 p1-52.indd 5212/16/2013 3:05:01 PM