# FINAL 2003 AQMP APPENDIX II

CURRENT AIR QUALITY

AUGUST 2003

## SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT

GOVERNING BOARD

Chairman: WILLIAM A. BURKE, Ed.D. Speaker of the Assembly Appointee

Vice-Chair: S. ROY WILSON, Ed.D. Supervisor, Fourth District Riverside County Representative

Members:

FRED AGUIAR Supervisor, Fourth District San Bernardino County Representative

MICHAEL D. ANTONOVICH Supervisor, Fifth District Los Angeles County Representative

HAL BERNSON Councilmember, City of Los Angeles Cities Representative, Los Angeles County/Western Region

JANE W. CARNEY Senate Rules Committee Appointee

WILLIAM CRAYCRAFT Councilmember, City of Mission Viejo Cities Representative, Orange County

BEATRICE LAPISTO-KIRTLEY Councilmember, City of Bradbury Cities Representative, Los Angeles County/Eastern Region

RONALD O. LOVERIDGE Mayor, City of Riverside Cities Representative, Riverside County

LEONARD PAULITZ Mayor Pro-Tem, City of Montclair Cities Representative, San Bernardino County

CYNTHIA VERDUGO-PERALTA Governor’s Appointee

JAMES W. SILVA Supervisor, Second District Orange County Representative

EXECUTIVE OFFICER Barry R. Wallerstein, D.Env.

# CONTRIBUTORS

Barry R. Wallerstein, D.Env.

Executive Officer

Elaine Chang, DrPH Deputy Executive Officer Planning, Rule Development and Area Sources

Laki Tisopulos, Ph.D., P.E. Assistant Deputy Executive Officer Planning, Rule Development and Area Sources

Zorik Pirveysian Planning and Rules Manager Planning, Rule Development and Area Sources

Authors: With the Assistance of: Planning & Rules

Joe Cassmassi

Shoreh Cohanim Information Technology

Curt Miller

Tom Parsons

Sandra Hom

Production: U. S. Environmental Protction Agency: Planning & Rules Patti Whiting Faye Thomas Region IX

Coe Owen

## Table Of Contents

i 

## Table of Contents

SUMMARY

Summary .................................................................................................................II-S-1

South Coast Air Basin..................................................................................II-S-1 Riverside County Salton Sea Air Basin.......................................................II-S-2 Seasonal, Day-of-Week and Diurnal Variations .........................................II-S-2



## CHAPTER 1 INTRODUCTION

Introductio n.............................................................................................................II-1-1 Air Quality Overview ..................................................................................II-1-1 Air Quality Standards a nd Episode Le vels..................................................II-1-2 South Coast Air Quality Ma nagement District............................................II-1-3 South Coast, Salton Sea and Moja ve Desert Air Basins .............................II-1-4

Weather ........................................................................................................II-1-4

Emissions. ....................................................................................................II-1-5 Air Quality Tr ends .......................................................................................II-1-6 Air Quality in the District Compared to Other Areas of the U.S. ...............II-1-6



## CHAPTER 2 AIR QUALITY IN THE SOUTH COAST AIR BASIN

Air Quality in the South Coast Air Basin ...............................................................II-2-1 Ozone (O 3 

## ) ...................................................................................................II-2-1

Carbon Monoxide (CO)...............................................................................II-2-9 Suspended Particulate Matter (PM 10 

## ) ........................................................II-2-14 Suspended Particulate Matter (PM 2.5 

## )........................................................II-2-19 Nitrogen Dioxide (NO 2 

## ).............................................................................II-2-22 Sulfur Dioxide (SO 2 

## ) .................................................................................II-2-24 Sulfate (SO 4 = 

## ).............................................................................................II-2-25 Lead (Pb) ....................................................................................................II-2-26



## CHAPTER 3 AIR QUALITY IN THE RIVERSIDE COUNTY SSAB

Air Quality in the Rive rside County SSAB............................................................II-3-1 Ozone (O 3 

## ) ...................................................................................................II-3-2 Suspended Particulate Matter (PM 10 

## ) ..........................................................II-3-2 Suspended Particulate Matter (PM 2.5 

## )..........................................................II-3-3

Carbon Monoxide (CO)...............................................................................II-3-4 Nitrogen Dioxide (NO 2 

## )...............................................................................II-3-4 Sulfur Dioxide (SO 2 

## ) ...................................................................................II-3-4

## Final 2003 AQMP Appendix II: Current Air Quality

ii Sulfate (SO 4 = 

## )...............................................................................................II-3-4 Lead (Pb) ......................................................................................................II-3-5



## ATTACHMENT

LIST OF FIGURES:

Figure 1-1: 2001 Maximum Pollu tant Concentrations As

Percent of Sta ndards ....................................................................................II-1-1

Figure 1-2: South Coast Air Qua lity Management District...................................II-1-3

Figure 1-3: 1997 Average Daily Emissions...........................................................II-1-5

Figure 1-4: Percent Basin-Days Exceeding the Federal Satandard,

1976-2001 ....................................................................................................II-1-6

Figure 1-5: Ozone - 1998-2000, Average Number of Days Exceeding Federal Standard ........................................................................II-1-7

Figure 2-1: Monthly Number of Days Ex ceeding Federal Standards in 2001 ......II-2-2

Figure 2-2: Ozone - 2001, Number of Days Exceeding 1-Hour

Federal Standard ..........................................................................................II-2-4

Figure 2-3: Ozone - 2001, Number of Days Exceeding 8-Hour

Federal Standard ..........................................................................................II-2-5

Figure 2-4: 5-Year Average Numb er of Days Per Month Exceeding

Federal Ozone Standard in the Basin...........................................................II-2-6

Figure 2-5: Ozone, Diurnal Varia tion, May-October 2001, Maximum

Concentration for Each Hour .......................................................................II-2-7

Figure 2-6: Ozone, Day-of-Week Variation, 1999-2001, Exceedances

of the Federal Standard by Day of Week.....................................................II-2-8

Figure 2-7: Carbon Monoxide - 2001, Maximum 8-Hour Average Concentration, ppm.................................................................................... II-2-10

Figure 2-8: Carbon Monoxide, Seas onal Variation, 1999-2001, Average Monthly Exceedances of Fe deral Standard ...............................................II-2-11

Figure 2-9: Carbon Monoxide, Diur nal Variation, 2001, Maximum

Concentration for Each Hour .....................................................................II-2-12

## Table Of Contents

iii Figure 2-10: Carbon Monoxide, Da y-of-Week Variation, 1999-2001, Average Concentrations by Day of W eek .................................................II-2-13

Figure 2-11: Chemical Composition of PM 10 

## , 1995............................................ II-2-15

Figure 2-12: Suspended Particulate Matter (PM 10 

## ) - 2001, Annual Arithmetic Mean, μg/m 3............................................................................II-2-17

Figure 2-13: Basin-Days Exceeding State PM 10 

## Standard by Month, 1999- 2001 .....................................................................................II-2 -18

Figure 2-14: Monthly Average PM 10 

## Concentration, 1999-2001........................ II-2-18

Figure 2-15: Day-of-Week Va riation, 1999-2001, Average PM 10 

## Concentration by Da y of Week .................................................................II-2-19

Figure 2-16: Suspended Particulate Matter (PM 2.5 

## ) - 2001, Annual Arithmetic Mean, μg/m 3............................................................................II-2-20

Figure 2-17: PM 2.5 

## Seasonal Variation, 1999-2001, Average Number of Basin-Days Exceeding Federa l Standard by Month .............................II-2-21

Figure 2-18: PM 2.5 

## Day-of-Week Variati on, 1999-2001, Basin-Days Exceeding the Federal Standa rd by Day of Week.....................................II-2-22

Figure 3-1: Maximum Pollutant C oncentrations as Percent of Standards, Riversid e County SS AB ............................................................II-3-1



## LIST OF TABLES:

Table 1: 2001 Maximum Annual Average Nitrogen Dioxide

Concentrati ons ...........................................................................................II-2-23

Table 2: 2001 Maximum 24-Hour Average Sulfur Dioxide

Concentrati ons ...........................................................................................II-2-25

Table 3: 2001 Maximum 24-Hour Aver age Sulfate Concentrations...................II-2-26

Table 4: 2001 Maximum Quarterly Average Lead Concentrations ....................II-2-27

## Final 2003 AQMP Appendix II: Current Air Quality

iv 

## ATTACHMENT LIST:

Table A-1: Ambient Air Quality Standards

Table A-2: Episode Criteria

Table A-3: Air Monitoring Sta tions and Source/Receptor Areas

Figure A-1:South Coast Air Basin and Ad joining Areas of SaltonSea Air Basin

Table A-4: Ozone - Number of Da ys Exceeding the Federal Standard

Table A-5: Ozone, 1976 - 2001, Annual Nu mber of Days of First/Second Stage Episodes

Table A-6: Ozone - Annua l Maximum 1-Hour, ppm, 1955-2001

Table A-7: Carbon Monoxide - Number of Days Maximum 8-Hour Average

Exceeded the Federal Standard

Table A-8: Carbon Monoxide - Number of Days Maximum 8-Hour Average

Exceeded the Federal Alert Level

Table A-9: Carbon Monoxide, Annual Maximum 8-Hour Average, ppm,

1976-2001

Table A-10: Suspended Particulates (PM 10 

## ), Annual Arithmetic Mean,

μ g/m 3 

## , 1985-2001

Table A-11: Suspended Particulates (PM 10 

## ), Annual Geometric Mean,

μ g/m 3 

## , 1985-2001

Table A-12: Suspended Particulates (PM 10 

## ) - Percent of Sampling Days Exceeding State Standard a nd Federal Standards, 1985-2001

Table A-13: Suspended Particulates (PM 10 

## ), Annual Maximum 24-Hour Average, μ g/m 3 , 1985-2001

Table A-14: Nitrogen Dioxide - A nnual Average of All Hours, pphm,

1976-2001

Table A-15: Nitrogen Dioxide - Number of Days 1-Hour Average Exceeded the State Standard, 1976-2001

Table A-16: Nitrogen Dioxide, Annual Maximum 1-Hour, ppm, 1976-2001

## Table Of Contents

v Table A-17: Sulfur Dioxide - Annual Average, pphm, 1976-2001

Table A-18: Sulfur Dioxide, Annua l Maximum 1-Hour Average, ppm,

1976-2001

Table A-19: Sulfate - Percent of Sampling Days Exceeding the State Standard, 1976-2001

Table A-20: Sulfate - Maxi mum 24-Hour Averages, 1976-2001

Table A-21: Lead - Highest Calendar Quarter Mean, μ g/m 3 

## , 1976-2001

Table A-22: Lead - Highest Monthly Averages, μ g/m 3 

## , 1976-2001

# CHAPTER 1

INTRODUCTION

## Chapter 1 Introduction

II-1-1 

## INTRODUCTION

Air Quality Overview

In 2001, the South Coast Air Quality Mana gement District (District) monitored ambient air quality for criteria pollutants (ozone, carbon monoxide , nitrogen dioxide, sulfur dioxide, particulate matters, lead a nd sulfate) at 32 loca tions in Southern California’s South Coast Air Basin (Basin ) and in the neighbor ing areas of the Salton Sea Air Basin (SSAB) that are within the District's jurisdiction. Pollutant

concentrations exceeded federal and/or st ate standard(s) for ozone and particulate matters (PM10 and PM2.5). Figure 1-1 shows the maximum pollutant concentrations for 2001 as a percen tage of the federal standards.

* There is no federal standard for sulfate. ** Higher measurements were recorded at special monitoring sites immediately adjacent to sources.



## FIGURE 1-1

2001 Maximum Pollutant Concentrati ons as Percent of Standards

Maximum 1-hour average and 8-hour averag e ozone concentrations in 2001 (0.190 ppm and 0.144 ppm) were 152% and 169% of the fe deral 1-hour and 8-hour standards, respectively. Maximum 24-hour average and annual average PM10 concentrations (219 μg/m 3 

## and 63.1 μg/m 3 

## ) were 146% and 125% of the federal 24- Percent of Standard

0 50 100 150 200 250

Ozone Ozone Carbon Nitrogen Sulfur PM2.5 PM10 Sulfate* Lead**

Monoxide Dioxide Dioxide

(1-Hour) (8-Hour) (8-Hour) (Annual) (Annual) (Annual) (Annual) (24-Hour) (Quarter) 

### STANDARD

## Final 2003 AQMP Appendix II: Current Air Quality

II-1-2 hour and annual standards, respectively. Maximum 24-hour average and annual average PM2.5 concentrations (98.0 μg/m 3 

## and 31.1 μg/m 3 

## ) were, respectively,

150% and 201% of the federal 24-hour a nd annual standards. Carbon monoxide

concentration did not exceed the standa rds in 2001. The highest 8-hour average

carbon monoxide concentration of the year (7.71 ppm) was 81% of the federal

standard.

In 2001, the federal nitrogen dioxide sta ndard was not exceeded, with a maximum concentration (0.0419 ppm) which was 78% of the federal standard. The maximum 1-hour average nitrogen dioxi de concentration (0.25 ppm) was 96% of the state

standard. The maximum 24-hour su lfate concentration (20.6 μg/m 3 

## ) was 82% of the state standard. (There is no federal sulf ate standard.) Sulfur dioxide and lead

concentrations continued to remain well below the federal and state standards in

2001.



## Air Quality Standards and Episode Levels

Both the federal and state governments have adopted ambient air quality standards,

which define the concentration below which long-term exposure to a pollutant is not expected to cause adverse eff ects to public health and welf are. Episode levels have also been established, below which short- term exposures are not expected to be injurious to health. The standards and episode levels are summarized in Tables A-1

and A-2 in the Attachment.

Both standards and episode levels are pe riodically reviewed to incorporate the findings from the most current research ava ilable on effects of pollutants. In 1997, the U.S. EPA adopted new federal air qua lity standards for particulate matter and ozone. The 8-hour average ozone standard (0.08 ppm) would protect the public health against the effects of prolonged expos ure and represents a tightening of the 1- hour ozone standard. For particulate ma tter, annual and 24-hour standards for the finest fraction of particulate, PM2.5 (particles less than 2.5 micrometer), was established to complement the PM10 federa l and state standards that target a full range of inhalable particulate matter. PM2.5 is estimated to be the most injurious to health and causes the greatest visibility reduction. The form of the 24-hour PM10

standard was also revised. The 1-hour average ozone standard and the annual PM10

standard are retained.

## Chapter 1 Introduction

II-1-3 

## South Coast Air Quality Management District

California’s first local air pollution cont rol agency, the Los Angeles County Air Pollution Control District (LAAPCD), was formed in 1947 and APCDs were formed in Orange, Riverside, and San Bernardino counties not l ong afterward. These four agencies combined in 1976 to form the S outhern California APCD, which was later replaced by the South Coast Air Quality Management District and the Mojave

Desert APCD.

The South Coast Air Quality Management District was established by state legislation effective February 1, 1977, a nd was assigned jurisdiction over air quality

in the South Coast Air Basin. The District is also responsible for air quality in the Riverside county area of the Salton Sea Ai r Basin (SSAB), by contract with the county. The South Coast Air Quality Management District is the name applied both to the agency and to the geographic juri sdiction which region it serves. The region encompassed by the District is shown in Figure 1-2. In 2001, the District maintained a network of 30 air monitoring stations in the Basin and an additional two in the District portions of SSAB (s hown in Figure A-1 a nd Table A-3 in the

Attachment). Antelope Valley

COUNTY 

### MDAB

South Coast Air Quality Management District

50 0 SOUTH C OAST AIR B ASIN (SOCA B) MOJAV E DE SE RT AIR BASIN (M DAB)

SCA QMD J URISDIC TION

J UN E 1996 R EVISION MILES LOS ANGELES COUNTY

RI VER SIDE C OUNT Y KE RN C OUNTY

IMPERIAL COUNT Y SAN DIEGO COUN TY COUNTY BOUNDAR IES Antelope Valley

SCAQM D AIR
MONITOR ING STATION COU NTY SAN BERNARDINO 

### SOCAB

ORANGE

COUNTY Coachella Valley



### SSAB

SA LTON SEA AIR B ASIN (SSAB)

## Final 2003 AQMP Appendix II: Current Air Quality

II-1-4 FIGURE 1-2 South Coast Air Quality Management District



## South Coast, Salton Sea and Mojave Desert Air Basins

The South Coast Air Basin (Basin) has an area of 6800 square miles and the population was 15 million in 2001. It incl udes all of Orange county and the nondesert areas of Los Angeles, Riversid e and San Bernardino counties. The Los Angeles urban area (the nation’s second largest) and the Anaheim-Fullerton and

Riverside-San Bernardino urba n areas lie within the Ba sin’s boundaries. About twothirds of the Basin’s population liv es within Los Angeles county.

The Salton Sea Air Basin and the Moja ve Desert Air Basin (MDAB) have a combined area of approximately 32,200 square miles. The two Basins include the desert portions of Los Ange les, Riverside and San Bern ardino counties as well as Imperial county and part of Kern county.

The SSAB and MDAB were previously incl uded in a single large Basin called the Southeast Desert Air Basin (SEDAB). The SEDAB also included the San Gorgonio Pass area. On May 30, 1996, the Califor nia Air Resources Board replaced the SEDAB with the SSAB and MDAB, and tran sferred the San Gorgonio Pass area to the Basin. In July 1997, the Antelope Va lley area of MDAB was separated from the District and incorporated into a new air district under the jurisdiction of the newly formed Antelope Valley Air Pollu tion Control District (AVAPCD).

The South Coast Air Quality Management District has the jurisdiction over the Coachella Valley portion of Riverside c ounty in SSAB. The population in the SSAB portion under the jurisdiction of the Di strict is about 300,000. The District also has the jurisdiction over a small por tion of the MDAB in eastern Riverside county. The area is sparcely populated desert.



## Weather

The South Coast Air Basin is arid, with virtually no ra infall and abundant sunshine during the summer months. It has light wi nds and poor vertical mixing compared to the other large urban areas in the U.S. The combination of poor dispersion and abundant sunshine pr ovide conditions especially fa vorable to the formation of photochemical smog. The Basin is also bounded to the north a nd east by mountains with maximum elevations exceeding 10,000 feet. The unfavorable combination of meteorology, topography, and emissions from the nation’s second largest urban area result in the Basin having the worst ai r quality in the U.S. More detailed information on Basin climatology appeared in a previous District publication.

## Chapter 1 Introduction

II-1-5 

## Emissions

The amount of each of the ma jor pollutants emitted into th e atmosphere of the Basin in 1997 is shown in Figur e 1-3. In 1997, approxi mately 7800 tons of carbon monoxide (CO), 1400 tons of oxides of nitrogen (NO

x 

## ), 1200 tons of volatile organic compounds (VOC), 80 tons of oxides of sulfur (SO

x 

## ), 330 tons of directly emitted particulate (PM10), 120 tons of finer particlate (PM2.5), and 600 tons of total suspended particulate (TSP) were em itted into the Basin’s atmosphere each day. (Additional PM10 forms by chemical reaction of the gaseous pollutants.) Emissions vary relatively little by season, but there are large seasonal differences in the atmospheric concentrations of polluta nts due to seasonal variations in the weather. (Details of the 1997 emissions inventory are contained in Appendix III.)

Volatile organic compounds and oxides of nitrogen are precur sors of ozone. Oxides of nitrogen and volatile orga nic compounds also react to form nitrates and solid organic compounds, which are a significant fra ction of PM10. Sulf ur dioxide reacts to form sulfates which are likewise signifi cant contributors to the Basin’s PM10 and PM2.5. In addition to the PM10 formed by reaction of gaseous precursors, there is directly emitted PM10, most of which is attributed to f ugitive dust sources such as re-entrained road dust, construction ac tivities, farming opera tions and wind-blown

dust.

FIGURE 1-3 1997 Average Daily Emissions in the Basin 01234567 PM2.5 PM10

TSP SOx NOx VOC

CO

Thousands Tons/Day

## Final 2003 AQMP Appendix II: Current Air Quality

II-1-6 

## Air Quality Trends

In 2001, the SCAB locations exceeded one or more of the federal standards on 37 days (excluding the recently adopted 8-hour ozone and PM2.5 standards exceedances).

Figure 1-4 shows the long-term annual trend of percent "basin-days" exceedances of the federal standards. (A "basin-day" is recorded if any locati on in the South Coast Air Basin exceeds the standard. Multiple lo cations exceeding on the same day count as a single basin-day.)

FIGURE 1-4 Percent Basin-Days Exceeding the Federal Standards, 1976-2001



## Air Quality in the District Comp ared to Other Areas of the U.S.

Despite the significant downtrend, the Sout h Coast Air Basin still has some of the worst air quality in the nation in terms of the annual number of days exceeding the federal standards. In 2001, the highest U. S. location in terms of number of days

over the federal ozone standard was locate d in the Basin (Central San Bernardino Percent Basin-Days

0% 25% 50% 75% 100%

76 78 80 82 84 86 88 90 92 94 96 98 00



### All Standards O3 (1-Hour)

CO (8-Hour) PM10 (24-Hour)

## Chapter 1 Introduction

II-1-7 Mountains, 26 days). Other area with the greatest number of exceedances outside

California was located in the Houston Me tropolitan Area, Texas (10 days). Figure 1-5 shows the average numbe r of days on which the federal ozone standard was exceeded at U.S. locations for the years 1998-2000.

Over the past decade, reductions in ve hicular emissions have reduced carbon monoxide levels throughout th e U.S., and many areas ha ve ceased violating the standards. In 2001, the Basin continued to rank among the areas of the U.S. with high 8-hour average carbon m onoxide concentration, alt hough it did not exceed the

standards.

The Basin exceeded the federal 24-hour av erage and annual PM10 standards in a few areas in 2001. The highest 24-hour av erage PM10 concentration in the U.S.

was recorded at a location in the Great Basin Valleys Air Basin in California. More detailed information on air qua lity in the U.S. is available in EPA's annual National Air Quality and Emi ssions Trend Report.

FIGURE 1-5 OZONE, 1998-2000 Average Number of Days Exceeding the Federal Standard

## Final 2003 AQMP Appendix II: Current Air Quality

II-1-8 The following two chapters of this re port summarize current air quality in the District. Analyses are presented for:

• Ozone (O 3 

## )

• Carbon monoxide (CO)

• Nitrogen dioxide (NO 2 

## )

• Sulfur dioxide (SO 2 

## )

• Particulate matter (PM10)

• Particulate matter (PM2.5)

• Lead (Pb)

• Sulfate (SO 4 = 

## )

Chapters 2 and 3 contain summa ries of air quality in the South Coast Air Basin, and the Riverside county portion of Salton Sea Ai r Basin, respectively. Salton Sea Air Basin includes Coachella Valley. Fo r those pollutants still designated as nonattainment, maps are presented which s how how air quality varies in different areas in the Basin. Detailed air quality sta tistics for each of the District’s monitoring

locations in the Basin and SSAB are contai ned in the attachment to this report.

A brief update of air quality trends th rough 2001 are presented in this report. Detailed analyses of air quality trends in the Basin are available in Appendix II of the 1997 AQMP and the December editions of the Air Quality Standards Compliance Reports (AQSCR's).

# CHAPTER 2

AIR QUALITY IN THE SOUTH COAST AIR BASIN

## Chapter 2 Air Quality in the South Coast Air Basin

II-2-1 

## AIR QUALITY IN THE SOUTH COAST AIR BASIN

The maximum pollutant concentrations record ed at District monitoring stations in 2001 (Figure 1-1 in Chapter 1) were all recorded in the densely populated South Coast Air Basin. However, air quality in the Basin varies wi dely by season and by

area.

The prevailing daytime sea breeze tends to transport pollutants from coastal areas into the Basin’s inland valleys, and from th ere, still further inland into neighboring

areas of Salton Sea Air Basin of the Distri ct as well as the MDAB. Concentrations of primary pollutants (those em itted directly into the air) are typically highest close

to the sources which emit th em. However, secondary pollutants (those formed in the air by chemical reaction of precursors ) reach maximum concentrations some

distance downwind of the sources that emit th e precursors, due to the fact that the polluted air mass is moved inland many miles by the prevailing winds before

maximum concentrations are reached.

The Basin’s air quality varies with season due to seasonal differences in the weather. In Figure 2-1, the number of days excee ding federal standards for each criteria pollutant is shown for each month of 2001. All of the ozone exceedances occurred during the May to October “smog season.” Particulate matter (PM 10 

## and PM 2.5 

## ) standards are exceeded at times throughout th e year and do not ha ve a clear pattern

like ozone and carbon monoxide. PM 2.5 

## exceedances, however, typically occur more frequently during late fall and early winter months. The standards were exceeded on a total of 54 days in 2001 (37 days excluding PM 2.5 

## ).



## Ozone (O 3 

## )

Properties

The Basin's unique air pollution problem firs t began to be recognized in the 1940's. Unlike the smog in many other urban area s, the Los Angeles smog was worse in summer. Early research showed that oz one was being formed in the Basin's atmosphere from hydrocarbons and oxides of nitrogen being emitted into the air in the presence of steady sunshine. Regular monitoring of total oxidants was begun by the Los Angeles Air Pollution Control Dist rict (LAAPCD) in the 1950’s, and annual

maximum 1-hour ozone concentr ations in excess of 0.6 ppm were recorded at that

time.

Ozone (O 3 

## ), a colorless gas with a sharp odor, is a highly reactive form of oxygen. High ozone concentrations ex ist naturally in the stratosphere. Some mixing of stratospheric ozone downward through the troposphere to the earth's surface does occur; however, the extent of ozone transpor t is limited. At th e earth's surface in

## Final 2003 AQMP Appendix II: Current Air Quality

II-2-2 sites remote from urban areas ozone con centrations are normally very low (0.03- 0.05 ppm).

* Basin-days represents the number of days a standard was exceeded anywhere in the Basin. ** Number of exceedances due to PM10 may have been higher, since PM10 samples are collected every 6 days (or every 3 days at a few sites).



## FIGURE 2-1 Monthly Number of Days Exc eeding Federal Standards in 2001

In urban areas, ozone is formed by a complicated series of chemical and photochemical reactions between reactive organic compounds, n itrogen oxides, and the oxygen in the air. A d ecrease in ozone precursors may or may not give a

decrease in ozone. Ozone concentra tions are dependent not only on overall precursor emissions, but on the ratio of hydrocarbon concentration to oxides of nitrogen concentration, the reactivity of the specific hydrocarbons present, the spatial and temporal distribu tion of emissions, and weather.

While ozone is beneficial in the strato sphere because it filters out skin-cancercausing ultraviolet radiation, it is a highly re active oxidant. It is this reactivity which accounts for its damaging effects on material s, plants, and human health at the

earth's surface.

The propensity of ozone for reacting with organic materials causes it to be damaging to living cells, and ambient ozone concen trations in the Basin are frequently

sufficient to cause health effects. Ozone enters th e human body primarily through the respiratory tract and causes respir atory irritation and discomfort, makes breathing more difficult during exercise, and reduces the respiratory system's ability

Basin-Days Exceeding*

0 2 4 6 8 10 12 14

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ozone (1-Hour)

CO (8-Hour)

PM10 (24-Hour)**

PM2.5 (24-Hour)

2 or More Standards

## Chapter 2 Air Quality in the South Coast Air Basin

II-2-3 to remove inhaled particles and fight infection. People with respiratory diseases, children, the elderly, and people who exerci se heavily are more susceptible to the

effects of ozone.

Plants are sensitive to ozone at concentra tions well below the he alth-based standards and ozone is responsible for significant cr op damage. Ozone is also responsible for damage to forests and other ecosystems.

Federal 8-Hour Ozone Standard

Studies have shown that even relatively lo w concentrations of ozone, if continued for several hours, can significantly reduce lung function in norma l healthy people. In July 1997, the U.S. Environmental Prot ection Agency (U.S. EPA) adopted an 8- hour average federal ozone standard with a level of 0.08 ppm. The new standard was based on exposure studies reporting health effects associated with long-term (6 to 8 hours) exposures at leve ls below the level of the 1-hour standard. The 8-hour ozone standard is more stringent than the 1-hour standard and provides greater protection to public health than the 1-hour standard. It will he lp protect people who spend a significant amount of time worki ng or playing outdoors -- a group that is particularly vulnerable to the effects of ozone. The federal 1-hour ozone standard continues to apply in non-attainment ar eas (including the District), where the

standard is still violated.

The effect of the adopted 8-hour ozone st andard on this region's attainment of

federal ozone standards has been ev aluated by comparing the number of exceedances of the 1-hour standard (0.12 ppm 1-hour average) with the number of exceedances of 8-hour average concentr ations of 0.08 ppm . The number of

exceedances in different areas in the Ba sin and SSAB vary; however, there are a greater number of days exceeding the federa l 8-hour ozone standard level in most areas, especially in the inland valleys and adjacent mountains where high ozone concentrations normally occur.

Current Ozone Air Quality

In 2001, the District measured ozone concentrations at 28 regular ambient monitoring locations. The maximu m 1-hour average and 8-hour ozone concentrations in the Basin in 2001 (0. 190 ppm and 0.144) were 152% and 169% of the federal 1-hour and 8-hour standards, respectively, and 190% of the state

standard. The federal 1-hour ozone standard was exceed ed at one or more Basin locations on a total of 36 days, the 8-hour standard was exceed ed on 100 days. The

California state standard was exceeded on 121 days, and the health advisory level on 15 days. The stage 1 episode level (1-hour average ≥ 0.20 ppm) was not exceeded anywhere in the Basin for th e third consecutive year.

## Final 2003 AQMP Appendix II: Current Air Quality

II-2-4 Figure 2-2 is a contour diagram of the num ber of days exceedi ng the 1-hour federal

ozone standard in different areas of the Basin in 2001. The standard was exceeded most frequently in the Basin's Central San Bernardino Mountai ns and adjacent valleys. The coastal areas of Los Angele s and Orange counties and areas near the boundary between the Basin and San Diego c ounty did not exceed the 1-hour federal

ozone standard.

The more stringent state standard was exceed ed almost everywhere in the Basin with the greatest number of exceedances occu ring in the Central San Bernardino Mountains and adjacent valleys (not shown).

A decade ago, only the coastal areas of the Basin did not record exceedances of the stage 1 episode level (1-hour average O 3 

## greater than or equal to 0.20 ppm). In 2001, stage 1 episodes were not recorded anyw here in the Basin. In addition, there have been no exceedances of the stag e 2 episode level (1-hour average O 3 

## greater than or equal to 0.35 ppm) since 1988 and th e stage 3 episode level (1-hour average

O 3 

## greater than or equal to 0.50 ppm) has not been exceeded since 1974.

FIGURE 2-2

OZONE - 2001 Number of Days Exceeding 1-Hour Federal Standard (1-hour average ozone > 0.12 ppm)

## Chapter 2 Air Quality in the South Coast Air Basin

II-2-5 Figure 2-3 shows the number of days exceeding the 8-hour federal standard in the

Basin in 2001. The 8-hour federal ozone standard was also exceeded most frequently in the Basin's Central San Bernar dino Mountains and adjacent areas. The

federal standards were not exceeded in the coastal areas.

FIGURE 2-3

OZONE - 2001 Number of Days Exceeding 8-Hour Federal Standard (8-hour average ozone > 0.08 ppm)

Table A-4 in the Attachment shows the num ber of exceedances of the 1-hour federal

ozone standard at all District air monitori ng sites, for all years for which data was available during the period 1976-2001. Tabl es A-5 and A-6 s how the number of days exceeding stage 1 and stage 2 episode levels and the maximum1-hour ozone

concentrations.

## Final 2003 AQMP Appendix II: Current Air Quality

II-2-6 Seasonal Variation

Because photochemical reactions require sunlight to pro ceed, ozone formation is favored by strong solar radiation. Solar radiation is more intense and of longer duration, and temperature inversions are stronger and more persistent, in summer

than in winter. This causes ozone concen trations to be higher in summer than in

winter. Peak ozone concentr ations generally occur near the middle of the day during the period May through October.

Figure 2-4 shows the 5-year average of number of days per month exceeding the federal ozone standard for the period 1976-2000. Up until the late 1980's it was common to have days exceeding the federal ozone standard as ear ly as February and

as late as November and December. In late 1990's (since 1996) there have been no

federal standard exceedances recorded in the months of January-March and November-December. Also, the frequency of exceedances in fa ll (September and October) has been reduced signifi cantly in the recent years.

FIGURE 2-4 5-Year Average of Number of Days Per Month Exceeding Federal Ozone Standard in the Basin 0 5 10 15 20 25 30 35

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DECDays Exceeding 

### 76-80

81-85

86-90

91-95

96-00

## Chapter 2 Air Quality in the South Coast Air Basin

II-2-7 Diurnal Variation

Because time and sunlight are required for the precursor organi c gases and nitrogen oxides to react to form ozone, peak oz one concentrations usually occur from afternoon to early evening. By this time, the prevailing sea breeze has moved the polluted air mass miles inla nd from the major sources of precursor emissions. Figure 2-5 illustrates the maximum ozone c oncentrations for eac h hour of the day for the smog season (May-October) of 2001 at three representative areas in the Basin. The diurnal pattern in these areas, coastal area of Los Angeles county, inland valley area and San Bernardino mountain area, depicts diurnal formation and impact of ozone transport.

Ozone concentrations in the Basin are typically low during early morning hours, increasing rapidly after sunrise and peak ing in the afternoon. However, peak concentrations occur earlier in the day fo r coastal areas and later in the day for locations further downwind. Examining diurnal variation th roughout the District, the time of the peak concentration was found to vary from noon - 1 p.m. PST in coastal-central Los Angeles county, to 4 - 7 p.m. in the farthe st inland Basin and

SSAB locations.

FIGURE 2-5

OZONE Diurnal Variation, May-October 2001

Maximum Concentration for Each Hour 0 5 10 15 20 25

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

HOUR, PSTConcentration, ppm East San Gabriel Valley

South Coastal Los Angeles County

Central San Bernardino Mountains

## Final 2003 AQMP Appendix II: Current Air Quality

II-2-8 In East San Gabriel Valley, an area typical of the inland valley areas of the Basin where high ozone concentrations occur, conc entrations are usually low at night and remain relatively low until mid-morning, reaching peak concentrations in the afternoon around 1 - 3 p.m. Diurnal variation in the South Coastal Los Angeles county area where ozone concentrations are typically low, show a similar pattern except that the peak concentrations are lower. In the mountain area where the Basin's highest concentrations have been r ecorded in recent years, concentrations are usually higher all the times and the peak is reached later in the afternoon around 4 - 5 p.m. and remains relatively high thr ough out the evening hours during the smog

season.

Day-of-Week Variation

Since the mid-1970s, it has been documented th at ozone concentrations in the Basin are higher on weekends than on weekdays, in spite of the fact that ozone pollutant precursors are lower on weekends than on weekdays. Similar effects have been observed in some other metropolitan areas in the nation such as San Francisco, Washington D.C., Philadelphia and New York.

Figure 2-6 shows the three-year average number of exceedances of the federal 1-

hour ozone standard for each day of the week in the Basin for the period 1999-2001. The number of exceedances was higher on Sunda ys followed by Saturdays. Fridays

FIGURE 2-6

OZONE Day-of-Week Variation, 1999-2001 Exceedances of the Federal Standard by Day of Week Average Number of Exceedances

0 2 4 6 8 10 12

Mon Tue Wed Thu Fri S at S un

## Chapter 2 Air Quality in the South Coast Air Basin

II-2-9 exceeded least. Average ozone concentrati ons also show a patte rn similar to the average number of exceedances , with weekends tending to be higher than weekdays. The California Air Resources Board (ARB) ha s sponsored several research projects to study the causes of elevated ozone levels on weekends in the Basin. Changes in daily patterns that impact the quantity and temporal loading of emissions have been suggested as strongly contri buting to observations. Carr yover of matured precursor from weekdays to weekends is also suggested as contributing factor.



## Carbon Monoxide (CO)

Properties

Carbon monoxide (CO) is a co lorless, odorless, relatively inert gas. It is a trace constituent in the unpolluted troposphere, a nd is produced by both natural processes

and human activities. In remote areas far from human habitation, carbon monoxide occurs in air at an average background c oncentration of 0.04 ppm, primarily as a result of natural processes su ch as forest fires and the oxidation of methane. Global atmospheric mixing of CO from urban and industrial sources creates higher background concentrations (up to 0.20 ppm) near urban areas. The major source of CO in urban areas is incomplete combus tion of carbon-containing fuels, mainly gasoline. In 1997, 97% of the CO emitte d into the Basin's atmosphere was from mobile sources. Consequently, CO concen trations are generally highest in the vicinity of major concentrations of vehicular traffic.

Carbon monoxide is a primary pollutant, meaning that it is directly emitted into the air, not formed in the atmosphere by chemical reaction of precursors, as is the case with ozone and other secondary pollutants. Ambient concentrations of CO in the Basin exhibit large spatial and temporal vari ations, due to variations in the rate at which CO is emitted, and in the meteorol ogical conditions that govern transport and dilution. Unlike ozone, CO tends to reach high concentrations in the fall and winter months. The highest concentrations frequently occur on weekdays at times

consistent with rush hour traffic and late night during the coolest, most stable portion of the day.

When carbon monoxide is inhaled in suffici ent concentration, it can displace oxygen and bind with the hemoglobin in the blood, reducing the capacity of the blood to carry oxygen. Individuals most at risk from the effects of CO include heart patients, fetuses (unborn babies), smokers , and people who exercise heavily. Normal healthy individuals are affected at higher concen trations, which may cause impairment of manual dexterity, vision, learning ability, and performance of work . The results of studies concerning the combined effects of CO and other pollutants in animals have shown a synergistic effect af ter exposure to CO and ozone.

## Final 2003 AQMP Appendix II: Current Air Quality

II-2-10 Current Carbon Monoxide Air Quality

The District currently monitors carbon monoxide air quality at 23 of its 32 air monitoring stations. The highe st CO concentrations are found in coastal and central Los Angeles county. The highest 8-hour average CO concentration in 2001 (7.71 ppm) was recorded in South Central Los A ngeles county and was 81% of the federal

standard and 85% of the state standard. Th is was the lowest concentration recorded in the Basin since carbon monoxide monitoring began in this region. The highest 1- hour average concentration in 2001 (12.0 ppm ) was 33% of the federal and 57% of

the state 1-hour standards. Concentrations in the less urbanized areas of the Basin

and in the SSAB were well below the standards.

In 2001, for the first time since montori ng began, carbon monoxi de standards were not exceeded anywhere in the Basin. The Basin, however, conti nued to rank in the nation among the locations with the highe st carbon monoxide concentrations. Figure 2-7 shows the distribution of maximum 8-hour average carbon monoxide

concentrations in the Basin in 2001. Highest concentrations were recorded in Los Angeles county areas, in the areas of S outh Central Los Ange les county and West San Fernando Valley. There have been no exceedances of the stage 1 episode (federal alert) level (8-hour average CO grea ter than or equal to 15 ppm) since 1994.

FIGURE 2-7

CARBON MONOXIDE - 2001 Maximum 8-Hour Average Concentration, ppm

## Chapter 2 Air Quality in the South Coast Air Basin

II-2-11 The annual number of days exceeding the federal carbon monoxide standard at all monitoring sites during the period 1976-2001 is given in Table A-7 in Attachment.

Tables A-8 and A-9 show the annual number of federa l alerts and maximum CO concentrations for all sites for the years 1976-2001.

Seasonal Variation

Carbon monoxide concentrations in the Basin tend to be highest in the late fall and

winter months. This is due mainly to meteorological conditions which occur more frequently in late fall and winter; specifi cally, light winds and late night and early morning radiation inversions, which inhibit the vertical dispersion of pollutants. Also, mobile sources produce more CO emi ssions in colder temperatures. Figure 2- 8 shows the three-year average monthly number of exceedances of the federal CO standard for the years 1999-2001 in the Basin. In the late fall and winter months, the

actual number of exceedances for each of the three years 1999-2001 ranged from one day to four days per month in January and December. No exceedances of the CO standards were recorded during Febr uary through November of the years 1999-

2001.

FIGURE 2-8

CARBON MONOXIDE Seasonal Variation, 1999-2001 Average Monthly Exceedances of Federal Standard Average Number of Exceedances

0 1 2 3

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

## Final 2003 AQMP Appendix II: Current Air Quality

II-2-12 Diurnal Variation

Figure 2-9 shows the maximum concentrati on of carbon monoxide for each hour of the day for the winter months (January , February, November and December) of

2001 in the Basin areas where typically higher CO concentrations are recorded, all located in Los Angeles county. On aver age, the CO concentration exhibits two peaks: first at around 7 - 8 a.m., the time of morning rush traffic congestion. A second peak is typically observed at 10 - 11 p.m. after the evening commute. Hourly concentrations during the summer m onths were relativel y low at all hours, with the peak concentration for winter av eraging more than two times higher than the average peak concentra tion for summer. The seasona l and diurnal patterns in these Los Angeles county areas are typical of those found at most locations in the

District.

FIGURE 2-9

CARBON MONOXIDE Diurnal Variation, 2001

Maximum Concentration for Each Hour 0 5 10 15 20

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

HOUR, PSTConcentration, ppm South Central Los Angeles County

Southwest Coastal Los Angeles County

West San Fernando Valley

## Chapter 2 Air Quality in the South Coast Air Basin

II-2-13 Day-of-Week Variation

Concentrations of carbon monoxide a nd exceedances of the carbon monoxide

standards have been found to vary significantly with day of week. This is due to

variation in vehicular traffic and CO em issions by day of week. Figure 2-10 shows the three-year average maximum hourly concen trations for each day of the week in the South Central Los Angeles county area during the pe riod 1999-2001. The average concentration for weekends (due primarily to Sunday) was lower than the average concentration for weekdays (Monday to Friday). A similar pattern has been observed for day-of-week variation at most locations in the District.

FIGURE 2-10

CARBON MONOXIDE Day-of-Week Variation, 1999-2001 Average Concentrations by Day of Week Average Concentration, ppm

0.0 5.0 10.0 15.0 20.0

Mon Tue Wed Thu Fri Sat Sun 

### South Central Los Angeles County

## Final 2003 AQMP Appendix II: Current Air Quality

II-2-14 

## Suspended Particulate Matter

Total suspended particulate (TSP) is the name applied to the complex mixture of solid material suspended in the at mosphere. TSP is collected on a glass fiber filter by means of a high volume sampler. Samples are colle cted for a 24-hour period every sixth day,

and then returned to the Di strict laboratory for chemical analysis to determine the relative concentrations of sulfate, nitrate a nd lead. The federal and state standards for

lead and sulfate are based on analyses of TSP samples. In 2001, TSP samples were collected by the District at 13 sites. These samples were analyzed for sulfate and nitrate

and were found to contain an average of from 5 to 19 percent sulfate and 5 to 21 percent nitrate, depending on location. Lead concentrations were determined for 9 of the sites, and the average lead concentration range d from 0.03 to 0.06 percent of the TSP.

The fine fraction of TSP has greater effect s on health and visibility than the coarse fraction. In 1987 EPA adopted PM 10 

## standards, which replaced the earlier TSP

standards. PM 10 

## samples are collected on quartz filters with a size selective inlet high volume sampler. The District began PM 10 

## monitoring in late 1984.

In 1997, the U.S. EPA adopted new federal air quality standards for finer particulate
matter, PM 2.5 

## , to complement existing PM 10 

## standards that targ et the full range of inhalable particulate matter. In compliance with the adopted standard, the District

monitored PM 2.5 

## concentrations at 18 sites in 2001.



## Suspended Particulate Matter (PM 10 

## )

Properties

Of greatest concern to public health are the particles small enough to be inhaled into the deepest parts of the lung. Respirable pa rticles (particulate matter less than about 10 micrometers in diameter) can accumulate in th e respiratory system and aggravate health problems such as asthma, bronchitis and othe r lung diseases. Children, the elderly, exercising adults, and those suffering from asthma are especially vulnerable to PM 10 

## 's

adverse health effects.

PM 10 

## particles are both directly emitted or formed from diverse emission sources. Major sources of directly emitted (primary) PM 10 

## include re-suspended road dust or soil entrained into the atmosphere by wind or activities such as construction and agriculture. Other components of PM 10 

## form in the atmosphere (secondary PM 10 

## ) from precursor emissions of the gaseous pollutants.

In 2001, the District measured PM 10 

## concentrations at 18 loca tions. At the 7 locations

where both PM 10 

## and TSP were monitored, PM 10 

## averaged 50 to 76% of TSP. PM 10

## Chapter 2 Air Quality in the South Coast Air Basin

II-2-15 samples are routinely analyzed for sulfate and nitrate, and in 2001 sulfates constituted an average of 7 to 18% of PM 10 

## , and nitrates constituted 4 to 18% of PM 10



## .

An intensive study of PM 10 

## was conducted at six locati ons in 1995, using special samplers designed to allow deta iled chemical analyses of PM 10 

## . The study sites included five Basin locations in Central Orange county (CEOC), Centra l Los Angeles county (CELA), Pomona/Walnut Valley (PWV), Cent ral San Bernardino Valley (CSBV), and Metropolitan Riverside county (MRIV) areas a nd one remote area in San Nicolas Island (SANI).

Figure 2-11 shows the average amounts of sulfate (SO 4 = 

## ), nitrate (NO 3 - 

## ), ammonium (NH 4 + 

## ), organic carbon (OC), elemental carbon (EC), sodium (Na + 

## ), chloride (Cl - 

## ), and

other materials such as soil components in the PM 10 

## samples which were collected during 1995. Sulfates, nitrates, and organic carbon are typically formed in the air by reaction of gaseous precursors such as oxi des of nitrogen, oxide s of sulfur, volatile organic compounds (hydrocarbons and rela ted compounds) and ammonia, which are emitted by a variety of sources. Soil-related materials tend to be larger particles which are suspended in the air by human activity or by wind.

FIGURE 2-11 Chemical Composition of PM 10 

## , 1995 0 20 40 60 80 100

SANI CEOC CELA PWV CSBV MRIV

SO4= NO3- NH4+ OC EC Na Cl Others 

### μg/m 3

## Final 2003 AQMP Appendix II: Current Air Quality

II-2-16 San Nicolas Island, 80 miles o ffshore and remote from the Basin’s urban areas, recorded a very low average PM 10 

## (18 μg/m 3 

## ), which contained a relatively large fraction of Na and Cl (25% of the PM 10 

## ). The relatively high Na and Cl is due to the influx of sea salt from the surrounding ocean. The concentrations of, and in most cases percentages of, the other components (NH 4 + 

## , NO 3 - 

## , SO 4 = 

## , OC, EC, crustal material) were low compared

to mainland Basin sites.

PM 10 

## annual concentrations measured at the five Basin locations recorded PM 10 

## concentrations from 42 μg/m 3 

## to 78 μg/m 3 

## . These Basin sites contain relatively high proportions of sulfates (6-11%), nitrat es (22-26%), organi c carbon(15-20%), and elemental carbon (5-8%). These materials deri ve from stationary or mobile sources of pollution in the Basin. The amount of soil-relate d material in the air is also greater (17% to 31%), due to suspension of soil in the air by human activitie s such as re-entrainment

of road dust and construction.

Current PM 10 

## Air Quality

In 2001, the District measured PM 10 

## concentrations at 18 lo cations throughout the South Coast and Salton Sea Air Basins. Figur e 2-12 shows for 2001 the annual average (arithmetic mean) PM 10 

## concentrations in the Basin. The area which exceeded the federal standard (inside the dashed line) is limited to the areas of Riverside and San Bernardino counties close to Metropolitan Riverside county. The maximum annual average recorded (63.1 μg/m 3 

## in the Metropolitan Riversid e county area) was 125% of

the federal standard.

The federal 24-hour standard was exceeded at two Basin locations in the inland valley areas 2001 (not shown). The maximum 24-hour average concentration (219 μg/m 3


## recorded in Metropolitan Riverside county) was 146% of the federal 24-hour standard.

The more stringent state annual standard wa s exceeded in a much larger area than the federal annual standard, with most of the Ba sin and part of the Riverside county SSAB recording annual average concentrations above the standard. The maximum annual average (annual geometric mean PM 10 

## 54.3 μg/m 3 

## , recorded at Metropolitan Riverside county) was 180% of the state annual standard.

The state 24-hour PM 10 

## standard was exceeded at all locations monitored in the District.

The standard was exceeded most frequently in the Basin’s inland valleys, centering in Metropolitan Riverside county. The maximu m 24-hour average was 429% of the state

24-hour standard.

The annual arithmetic and geometric mean, th e percent of days exceeding state and federal standards, and the maximum 24-hour average concentration for the years 1985 - 2001 are given in Tables A-10 to A-13 in Attachment.

## Chapter 2 Air Quality in the South Coast Air Basin

II-2-17 FIGURE 2-12 Suspended Particulate Matter (PM 10 

## ) - 2001 Annual Arithmetic Mean, μg/m 3



## Seasonal and Day-of-Week Variation in PM 10



## PM 10 

## samples are only collected every sixth day (or third day at sites where an intensive monitoring schedule has been adopted) and ex ceedances of the federal standard are relatively infrequent in recent years. As a consequence, seas onal and day-of-week

variations in exceedances of the federal st andard for the last few years cannot be determined accurately. Howeve r, if exceedances of the stat e standard are considered, seasonal and day-of-week patterns do emerge.

Previous analyses of s easonal variations in PM 10 

## show that the monthly average PM 10 

## concentration and the monthly average number of days exceeding the state standard tend to peak in summer and fall in the in land valley area of the Basin where PM 10 

## concentrations are highest. However, in the South Coastal Los Angeles county area, monthly average PM 10 

## concentrations and the averag e number of days exceeding the state standard are highest in late fall and winter months.

Figure 2-13 shows the average number of da ys in each month exceeding the state

standard at one or more Basin locati ons over the period 1999-2001. The greatest

number of state standard exceedances occurre d in the summer and fall months. Due to higher number of exceedances in the inland va lleys, the pattern for the Basin is more

## Final 2003 AQMP Appendix II: Current Air Quality

II-2-18 similar to those for individual sites in th e inland valley areas. Figure 2-14 shows the monthly average PM 10 

## concentrations for the two site s, Metropolitan Riverside county in inland valleys and South Coas tal Los Angeles county. In the inland valley areas, PM 10 

## concentrations are higher in the summer and fa ll months while in th e coastal areas higher

concentrations are recorded in the late fall and winter months.

FIGURE 2-13 Basin-Days Exceeding State PM 10 

## Standard by Month, 1999-2001

FIGURE 2-14 Monthly Average PM 10 

## Concentration, 1999-2001 0 2 4 6 8 10

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecBasin-Days > 50 μg/m3

0 20 40 60 80 100



### Jan Feb Mar Apr May Jun Juy Aug Sep Oct Nov DecConcentration, ug/m3 

### Metropolitan Riverside County

South Coastal Los Angeles County

## Chapter 2 Air Quality in the South Coast Air Basin

II-2-19 Day-of-week variations have also been examined, and it was found that the average

weekend concentrations were lower than the weekday average at all sites monitored in

the Basin and SSAB locations. Figure 2-15 shows the average PM 10 

## concentrations by day of week at three representative mon itoring sites in the Basin for the period 1999- 2001, based on the Beta Attenuation Monito r (BAM) and Tapered Element Oscillating Microbalance (TEOM) data.

Diurnal variations proved to be complex and location dependent.

FIGURE 2-15 Day-of-Week Variation, 1999-2001 Average PM 10 

## Concentration by Day of Week



## Suspended Particulate Matter (PM 2.5 

## )

Properties

PM 2.5 

## , the fine sized particles less than 2.5 mi crometers in diameter, are small enough to penetrate the defenses of the human respirat ory system and lodge in the deepest recesses of the lung, causing adverse health impacts. The health effects include increased respiratory symptoms and diseases such as ashma, bronchitis , acute and chronic respiratory problems like shortness of breat h and painful breathi ng (in children, the elderly and sensitive people), and premature deaths (mainl y in the elderly due to a weaker immune system). The sources of PM 2.5 

## include diesel-powered vehicles such as 0 20 40 60 80

Mon Tue Wed Thu Fri Sat SunConcentration, ug/m3 Metropolitan Riverside County Central Los Angeles South Coastal Los Angeles County

## Final 2003 AQMP Appendix II: Current Air Quality

II-2-20 buses and trucks, fuel combustion from autom obiles, power plants, industrial processes, and wood burning.

In the South Coast Air Basin, much of the PM 10 

## fraction is actually finer in size than 2.5 

## micrometers, a condition which has major imp lications for both health and atmospheric visibility. Reducing PM 2.5 

## concentrations will therefore not only reduce the threat to the health of the Basin's population, but will also improve visual air quality in this region.

The District began monitoring PM 2.5 

## regularly in 1999. In 2001, the District measured

PM 2.5 

## concentrations at 18 locations. Sample s are collected for a 24-hour period every 3 days at most locations excep t for a few sites with high PM 2.5 

## levels where samples are taken every day.

Current PM 2.5 

## Air Quality

Figure 2-16 shows 2001 the annual average arithmetic mean PM 2.5 

## concentrations in

different areas of the Basin. Like PM 10 

## , PM 2.5 

## concentrations were higher in the inland valley areas of San Bernar dino county and Metropolitan Ri verside county. However,

PM 2.5 

## concentrations were also high in th e metropolitan areas of Los Angeles and Orange counties. The high PM 2.5 

## concentrations in these ar eas are mainly due to the

FIGURE 2-16 Suspended Particulate Matter (PM 2.5 

## ) - 2001 Annual Arithmetic Mean, μg/m 3

## Chapter 2 Air Quality in the South Coast Air Basin

II-2-21 secondary formation of smaller-sized partic ulate resulting from mobile and stationary

source activities. The maximum a nnual average recorded (31.1 μg/m 3 

## in the Metropolitan Riverside county area) was 201% of the federal standard. In 2001, the

federal annual PM 2.5 

## standard was exceeded everywhere in the District except for the

San Bernardino Mountain area in the Basin and Coachella Valley area in SSAB.

The federal 24-hour PM 2.5 

## standard was exceeded likewis e almost everywhere in the

Basin in 2001. The standard was exceeded mo st frequently in the metropolitan areas of Los Angeles and Riverside counties. Ma ximum 24-hour average concentration (98.0 μg/m 3 

## in Metropolitan Riverside county) was 150% of the federal 24-hour standard.

Seasonal and Day of Week Variation in PM 2.5



## Evaluation of the available data for the past two years that PM 2.5 

## has been monitored

shows that the PM 2.5 

## concentrations tend to peak during the late fall-winter months. Figure 2-17 shows the average number of da ys in each month exceeding the federal

standard at one or more Basin locations over the years 1999-2001. The greatest number of exceedances occurred in January and October-December.

FIGURE 2-17

PM 2.5 

## Seasonal Variation, 1999-2001 Average Number of Basin-Days Ex ceeding Federal Standard by Month

0 1 2 3 4 5

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecBasin-Days > 65 μg/m3

## Final 2003 AQMP Appendix II: Current Air Quality

II-2-22 Because PM 2.5 

## standards and monitoring requirements are of recent adaption, there is

insufficient data accumulated t hus far to accurately determ ine day-of-week trends in

PM 2.5 

## concentrations in the Basin. Preliminary analysis of available data shows slightly higher frequency of number of days exceeding the federa l standard on Sundays and Mondays. No specific day-of-wee k pattern was found in the in PM 2.5 

## concentrations in the Basin. Figure 2-18 the total number of days exceeding the federal standard in the Basin by day of week for the three-year period 1999-2001.

FIGURE 2-18

PM 2.5 

## Day-of-Week Variation, 1999-2001 Basin-Days Exceeding the Federa l Standard by Day of Week



## Nitrogen Dioxide (NO 2 

## )

Properties

Nitrogen dioxide (NO 2 

## ) is a reddish-brown gas with a bleach-like odor. Nitric oxide (NO) is a colorless gas, formed from the nitrogen (N 2 

## ) and oxygen (O 2 

## ) in air under conditions of high temperat ure and pressure which are generally present during combustion of fuels; NO reacts rapidly with the oxygen in air to give nitrogen dioxide (NO 2 

## ). NO 2 

## is responsible for the brownish tinge of polluted air. The two gases, nitric oxide and nitrogen dioxide, ar e referred to collectively as oxides of nitrogen (NO

x 

## ). In the presence of sunlight, nitroge n dioxide reacts to give nitr ic oxide and an oxygen atom. The oxygen atom can react further to give ozone, via a complex series of chemical 0 5 10 15

Mon Tue Wed Thu Fri Sat SunBasin-Days

## Chapter 2 Air Quality in the South Coast Air Basin

II-2-23 reactions involving hydrocarbons. Nitrogen dioxide may also react to give nitric acid (HNO 3 

## ) which reacts further to give nitrates, which are a component of PM 10



## .

Nitrogen dioxide is a respiratory irritant and reduces resistance to respiratory infection. Children and people with respiratory diseas e are most susceptible to its effects.

Current Nitrogen Dioxide Air Quality

In 2001, the District monitore d nitrogen dioxide concentrati ons at 23 locations. Federal and state standards for nitrogen dioxide were not exceeded at any location. The federal

standard has not been exceeded in the Basin since 1991.

Table 1 below shows the 2001 maximu m annual average nitrogen dioxide concentrations by Basin and county. The maximum annua l average nitrogen dioxide concentration (0.0419 ppm recorded in th e East San Fernando Valley area of Los Angeles county) was 78% of the federal st andard. Concentrations in the downwind

SSAB areas were much lower. The maximum 1-hour average concentration in the Basin (0.25 ppm in East San Fernando Valle y) was 96% of the state standard.

The annual averages, number of days exceed ing the state standard, and maximum 1-hour average concentrations for each individual area of the District for the years 1976-2001 are given in Tables A-14 to A-16 in Attachment.

TABLE 1 2001 Maximum Annual Average Nitr ogen Dioxide Concentrations*

Maximum Percent Basin/County Annual Avg. Federal Area ppm Standard

South Coast Air Basin Los Angeles 0.0419 78% East San Fernando Valley Orange 0.0293 55% Central Orange County Riverside 0.0247 46% Metropolitan Riverside County San Bernardino 0.0384 72% Northwest San Bernardino Valley

Salton Sea Air Basin Riverside 0.0175 33% Coachella Valley

* Federal standard = 0.0535 ppm

## Final 2003 AQMP Appendix II: Current Air Quality

II-2-24 Though the state and federal standards were not exceeded in 2001, nitrogen dioxide is still a concern since it is a precursor to both ozone and particulate matter. Further control of oxides of nitrogen will be requi red to attain the oz one and particulate

standards.



## Sulfur Dioxide (SO 2 

## )

Properties

Sulfur dioxide (SO 2 

## ) is a colorless gas with a sharp odo r. It reacts in the air to form sulfuric acid (H 2 

## SO 4 

## ), which contributes to acid precip itation, and sulfates, which are a component of PM 10 

## and PM 2.5 

## . Most of the SO 2 

## emitted into the atmosphere is produced by the burning of sulfur-containing fuels.

At sufficiently high concentrations, sulfur dioxide affects breathing and the lungs’ defenses, and can aggravate respiratory a nd cardiovascular diseases. Asthmatics and people with chronic lung dise ase or cardiovascular disease are most sensitive to its effects. Sulfur dioxide also causes plant da mage, damage to materials, and acidification

of lakes and streams.

Current Sulfur Dioxide Air Quality

In 2001, sulfur dioxide was meas ured at seven Basin locations. No violations of federal

or state standards occurred. The federal st andards were last exce eded in the 1960’s and

the state standard was last exceeded in 1990.

The maximum 24-hour average SO 2 

## concentrations recorded in the District in 2001 are shown in Table 2. The highest 24-hour average SO 2 

## concentration (0.012 ppm in South and Southwest Coastal Los Angeles count y areas) was 8% of the federal 24-hour standard. The highest 1-hour average (0.05 ppm in South Coastal Los Angeles county)

was 19% of the state standard. The ma ximum annual average concentration (0.0041 ppm in the Southwest Coastal Los Angele s county area) was 13% of the federal

standard.

Detailed statistics including annual av erage and maximum 1-hour average SO 2 

## concentrations for each location monitore d for the years 1976-2001 are given in in

Attachments A-17 and A-18.

While sulfur dioxide concentrations in the Basin no longer ex ceed standards, SO 2 

## is a precursor of PM 10 

## and sulfate.

## Chapter 2 Air Quality in the South Coast Air Basin

II-2-25 TABLE 2 2001 Maximum 24-Hour Average Sulf ur Dioxide Concentrations*

Maximum Percent Basin/County 24-hr Avg. Federal Area ppm Standard

South Coast Air Basin Los Angeles 0.012 8% Southwest Coastal LA County Orange 0.007 5% North Coastal Orange County Riverside 0.011 8% Metropolitan Riverside County San Bernardino 0.010 7% Central San Bernardino Valley

Salton Sea Air Basin

Riverside N.D.

N.D. = No Data. Historical measurements indicate concentrations are below standard.
* Federal standard = 0.14 ppm



## Sulfate (SO 4 = 

## )

Properties

Sulfates are chemical compounds wh ich contain the sulfate ion (SO 4 = 

## ), and are part of the mixture of solid materials which make up PM 10 

## and TSP. Most of the sulfates in the atmosphere are produced by oxidation of sulfur dioxide. Oxidation of sulfur dioxide yields sulfur trioxide (SO 3 

## ) which reacts with water to give sulfuric acid (H 2 

## SO 4 

## ), which contributes to acid precipitation. The reacti on of sulfuric acid with basic substances such as ammonia yields sulfates, a component of PM 10



## .

Current Sulfate Air Quality

In 2001 sulfate concentrations were measured at 13 Basin locations. Table 3 shows the 2001 maximum 24-hour average con centrations in the District by Basin and county. The maximum sulfate concentration (20.6 μg/m 3 

## ) recorded in the District was 82% of the

state standard.

The percent of days exceeding the sta ndard and the maximum 24-hour average concentration at each monitoring location for the years 1976-2001 are given in Tables

A-19 to A-20 in Attachment.

## Final 2003 AQMP Appendix II: Current Air Quality

II-2-26 TABLE 3 2001 Maximum 24-Hour Average Sulfate Concentrations

Maximum Percent Basin/County 24-hr. Avg. State Area

μg/m 3 

## Standard

South Coast Air Basin Los Angeles 20.6 82% Southwest Coastal LA County Orange N.D. Riverside 10.7 43% Metropolitan Riverside County San Bernardino 11.5 46% Central San Bernardino Valley

Salton Sea Air Basin

Riverside N.D.

N.D. = No Data. Historical measurements i ndicated concentrations were below standard.
* State standard = 25 μg/m3



## Lead (Pb)

Properties

Lead in the atmosphere is present as a mi xture of a number of lead compounds. Leaded gasoline and lead smelters have been the main sources of lead emitted into the air. Due to the phasing out of leaded gasoline, there was a dramatic reduction in atmospheric lead in the Basin over the past two decades. Howe ver, lead concentrations in excess of the

standards have been recorded since 1990 in ve ry localized areas near stationary sources

of lead.

Current Lead Air Quality

In 2001 lead concentrations were measured at nine Basin ai r monitoring stations, none of

which exceeded the state or federal standard s. Table 4 shows the maximum quarterly average lead concentrations in the Distri ct by Basin and county in 2001. The maximum quarterly average lead concentration (0.12 μg/m 3 

## ) was 8% of the federal standard. The maximum monthly average lead concentration (0.23 μg/m 3 

## ) was 15% of the state

standard.

## Chapter 2 Air Quality in the South Coast Air Basin

II-2-27 TABLE 4 2001 Maximum Quarterly Average Lead Concentrations

Maximum Percent Basin/County Qtr. Avg.* Federal Area

μg/m 3 

## Standard

South Coast Air Basin Los Angeles 0.12 8% South Central LA County Orange N.D. Riverside 0.03 2% Metropolitan Riverside County San Bernardino 0.04 3% Multiple Sites

Salton Sea Air Basin

Riverside N.D.

N.D. = No Data. Historical measurements i ndicated concentrations were below standard.
* Higher concentrations (0.49 μg/m3) were measured in localized areas near sources.



## In addition to lead measurements at Distri ct air monitoring stations, special monitoring was done in the immediate vicinity of several stationary sources of lead. Data from the special monitoring sites showed that highe r concentrations were reached in very localized areas near sources, with a maximum quarterly average (0.49 μg/m 3 

## ) 32% of the federal standard, and a maximum monthly average (0.57 μg/m 3 

## ) 38% of the state

standard.

Maximum quarterly average and monthly averag e lead concentrations at each of the regular monitoring sites for the years 1976-2001 are given in the Attachment, Tables A21 and A-22 in Attachment.

# CHAPTER 3

AIR QUALITY IN TH E RIVERSIDE COUNTY SSA B

## Chapter 3 Air Quality in the Riverside C ounty SSAB

II

- 3

- 1 

## AIR QUALITY IN THE R IVERSIDE COUNTY SSAB

In 2001 , the District monitored air quality at two locations in the Riverside county portion of the Salton Sea Desert Air Basin (SSAB), both in the Coachella Valley. One monitoring station was located immediately downwind of the densely populated Basin, and the other was located further downwind in the Coachella Valley. The maximum concentrations

recorded at these locations in 2001 are shown in Figure 3

- 1.

In 2001 , pollutant concentrations in the Riverside county SSAB exceeded standards for

ozone and PM10. The maximum 1

- hour average ozone concentration (0.1 37 ppm) was

1 37 % and 110 % of the state and federal standards, respectively. The maximum 8

- hour

average ozone concentration (0.1 14 ppm) was 1 3 4% of the 8

- hour federal ozone standard. The maximum annual average PM10 concentration (5 0.2 μg/m 3 

## ) was 99 % of the federal annual PM10 standard. (The annual average PM10 does not include the data for the samples col lected on high

- wind days in accordance with EPA's Natural Event Policy.) The maximum annual average PM2.5 concentration (1 2 .2 μg/m 3 

## ) was 7 9 % of the standard.

FIGURE 3

- 1

2001 Maximum Pollutant Concentrations as Percent of Standards

Riverside County SSAB Percent of Federal Standard

0 50 100 150

Ozone Ozone PM10 PM2.5 Carbon Monoxide Nitrogen Dioxide

(1-Hour) (8-Hour) (Annual) (Annual) (8-Hour) (Annual) 

## Coachella Valley

Federal Standard

## Final 2003 AQMP Appendix II: Current Air Quality

II

- 3

- 2 Federal and state standards for carbon monoxide and nitrogen dioxide were not exceeded. The highest 8

- hour average carbon monoxide concentration ( 1.75 ppm) was 16 % of the federal standard. The maximum annual average nitrogen dioxide concentration recorde d (0.017 5 ppm) was 33% of the federal NO 2 

## standard. No measurements of sulfur dioxide, sulfate or lead were made in the Riverside county SSAB area of the District in 2001

. Historical measurements in this area showed concentrations of these pollutants to be well below the state and federal standards and monitoring was discontinued. Detailed information on historical air quality and trends in air quality in this area was presented in a previous report.



## Ozone (O 3 

## )

Ozone in the atmosphere of the Riverside co unty portion of SSAB is both directly transported from the Basin and formed principally from precursors emitted upwind. These precursors are emitted in greatest quantity in the coastal and central Los Angeles county areas of the Basin. The Basin’s prevai ling sea breeze causes polluted air to be transported inland. As the air is being transported inland, ozone is formed, with peak concentrations occurring in the inland valleys of the Basin in an area extending from eastern San Fernando Valley through the San Gabriel Valley into the Riverside

- San Bernardino area and the adjacent mountains. As the air is transported still further inland into the desert areas,

ozone concentrations decrease.

The 1

- hour federal o zone standard level was exceeded on a maximum of six days in Coachella Valley in 2001 . The more stringent 8

- hour federal standard was exceeded on 42 days. Ozone concentrations and the number of days exceeding the federal ozone standard are greatest in summer. There are typically no exceedances during the winter months.

The 1

- hour state ozone standard was exceeded on a maximum of 5 3 days in Coachella Valley in 2001 . The health advisory level has not been exceeded in the Coachella Valley area since 1999. No stage 1 episode level has been recorded in t he Riverside county SSAB

areas since 1989.

Number of days exceeding the 1

- hour federal ozone standard and episode levels and the

maximum 1

- hour ozone concentrations for the years 1976

- 2001 are given in the
Attachment, in Tables A

- 4 through A

- 6.



## Particulate Matter (PM10)

Although exceedances of the ozone standard in the Coachella Valley area are due to the transport of ozone from the densely populated areas of the Basin upwind, the same cannot

be said for PM10 exceedances. PM10 exceedances in the Coachella Valley are primarily due to locally generated sources of fugitive dust (e.g. construction activities, re

- entrained

## Chapter 3 Air Quality in the Riverside C ounty SSAB

II

- 3

- 3 dust from paved road travel, and natural wind

- blown sources) and not as a result of secondary PM10 generated from precursor gaseous emissions . In addition, the Riverside county SSAB is subject to frequent high winds which generate wind

- blown sand and dust that can cause high levels of PM10. PM10 is the only pollutant which has sometimes reached higher concentrations in SSAB than in the densel y populated Basin.

In 2001 , the federal 24

- hour PM10 standard was exceeded in Coachella Valley on a maximum of five days (

4 % of sampling days). All samples which exceeded the standard were collected on high

- wind days which resulted in windblown dust. The data for these samples are excluded from the data base in accordance with the EPA's Natural Event Policy. The federal annual PM10 standard level was not exceeded in the Riverside county part of SSAB in 2001 . The maximum annual average PM10 concentration (5 0.2 μg/m

3 

## )

was 99 % of the standard.

The maximum annual average PM10 concentrations in the western portion of the Coachella Valley area, as well as the San Gorgonio Pass area at the eastern edge of the Basin,

remained well below the federal PM10 standa rds in 2001

.

In 2001 , the state 24

- hour PM10 standard was exceeded on a maximum of 5 0 days ( 4 5% of sampling days) in Coachella Valley

. The state annual standard was also exceeded. The maximum annual average (4 4.3 μg/m 3 

## , annual geometric mean) was 147 % of the state

standard.

Analyses of the seasonal distribution of exceedances of the PM10 standards showed a pattern similar to the inland valleys with a peak in summer and falling to a minimum in

winter.

Variation in average concentration by day

- of

- week in Coachella Valley also shows the same pattern as other areas in the Basin, with concentrations lower on weekends than on week days.

Annual average, percent number of days exceeding standards and maximum 24

- hour average concentrations for the years 1985

- 20 01 for the Riverside county SSAB and other District air monitoring stations are presented in the Attachment, in Tables A

- 10 to A

- 13.



## Particulate Matter (PM2.5)

PM2.5 has been measured in Coachella Valley since 1999 when the District began PM2.5 monitoring. In 2001 , federal PM2.5 standards were not exceeded at either of the two Riverside county SSAB air monitoring sites. The maximum 24

- hour average and annual average concentrations recorded in 2001 ( 44.7 μg/m 3 

## and 1 2.2 μg/m

3 

## ) were, respectively,

68 % and 7 9 % of the federal 24

- hour and annual standards.

## Final 2003 AQMP Appendix II: Current Air Quality

II

- 3

- 4 

## Carbon Monoxide (CO)

Carbon monoxide was measured at one of the Riverside county SSAB air monitoring

stations in 2001 . Neither the federal nor state standards were exceeded. The maximum 8

- hour average CO r ecorded in 2001 ( 1.75 ppm) was 16 % of the federal and 19 % of the state standards. Historical carbon monoxide air quality and trends in the Riverside county SSAB

area shows that the area has not exceeded the federal standard over the last two decades.

Su mmary statistics for carbon monoxide in the Riverside county SSAB as well as other District areas are given in the Attachment, in Tables A

- 7 to A

- 9.



## Nitrogen Dioxide (NO 2 

## )

Nitrogen dioxide was measured at one of the stations in the Riverside county SSAB in

2001 . The maximum annual average nitrogen dioxide concentration (0.017 5 ppm) was

33% of the federal standard and the maximum 1

- hour average (0.0 8 ppm) was 31 % of the

state 1

- hour standard.

Table 1 (Chapter 2) and Tables A

- 15 to A

- 17 in the Attachment c ontain nitrogen dioxide summary statistics for the Riverside county SSAB and other District monitoring stations for the year 2001 and earlier years.



## Sulfur Dioxide (SO 2 

## )

Sulfur dioxide concentrations were not measured in the Riverside county SSAB in 2001

. Measurements made in past years have shown concentrations to be well below the standard.

Tables A

- 17 and A

- 18 in the Atthachment contain annual average and maximum 1

- hour averages for available years for the period 1976

- 2001 at Riverside county SSAB and o ther District monitoring stations.



## Sulfate (SO 4 = 

## )

No measurements of sulfate concentrations were made in 2001 at the two monitoring stations in the Riverside county SSAB. Historical monitoring has shown concentrations to

be less than the state standard.

T he percent of days exceeding the standard, and the maximum 24

- hour average and annual average sulfate concentrations at each monitoring location for past years are presented in
the Attachment, in Tables A

- 20 to A

- 22.

## Chapter 3 Air Quality in the Riverside C ounty SSAB

II

- 3

- 5 

## Lead (Pb)

Lead concentrations were not measured at the two Riverside county SSAB stations in

2001 . Measurements made in past years have shown concentrations to be less than the

state and federa standards.

Maximum quarterly average and monthly average concentrations for past years are given in

Tables A

- 23 and A

- 24 in the Attachment.

# SUMMARY

## Summary

II-S-1 

## SUMMARY

This report contains a summary of the year 2001 air quality in the South Coast Air Basin and the portion of Salton Sea Air Basin m onitored by the South Coast Air Quality Management District. For those pollutants for which the Basin is in nonattainment of the federal standards, an updated air quality trends through the year 2001 are presented. 1



## In 2001 the South Coast Air Qua lity Management District m onitored concentrations of air pollutants at 32 locations in Southern California’s Los Angeles, Orange, Riverside

and San Bernardino counties. Pollutant concentrations exceeded the federal and state standards for ozone and particulate matte r (PM10, PM2.5). Standards for carbon monoxide, nitrogen dioxide, su lfur dioxide, sulfate and lead were not exceeded.

In the year 2001, the U.S. loca tion with the highest number of days exceeding the federal

ozone standard was located in the South Coast Air Basin (Orange county and the nondesert portions of Los Angeles, Riverside a nd San Bernardino countie s). The Basin also continued to rank among the areas of th e U.S. with high car bon monoxide and PM10

concentrations in 2001.



## South Coast Air Basin (SCAB)

In 2001, there were a total of 37 days on wh ich the federal standards for 1-hour ozone

and 24-hour PM10 were exceeded at one or more SCAB (Basin) locations. The recently adopted federal 24-hour PM2.5 standard was exceeded on 23 days in the Basin.

The number of days exceeding the federal oz one standard varied widely by area, from zero to 26 exceedances, depending on location. Exceedances were fewest at the coast, increasing to a maximum in the Basin's Ce ntral San Bernardino Mountains and inland valleys, and then decreasing further downwi nd in the Basin’s far inland areas. The

Central San Bernardino Mountai ns area exceeded the federal ozone standard most frequently (26 days). The more stringent state standard was exceeded on 88 days in the same area. The highest 1-hour average and 8-hour average oz one concentration recorded in 2001 (0.190 ppm and 0.144 ppm) were 152% and 169% of the federal 1- hour and 8-hour standards, respectively.

In 2001, carbon monoxide concentr ations did not exceed the st andards anywhere in the Basin. The highest carbon monoxi de concentrations were recorded in coastal and central Los Angeles county areas. The maximum 8- hour average concentration of 7.71 ppm, recorded in South Central Los Angeles C ounty, was 81% of the federal standard.

1 

### The current air quality analysis presented in this repor t is based on the data through the year 2001. Complete particulate data for the year 2002 is not available at this time.

## Final 2003 AQMP Appendix II: Current Air Quality

II-S-2 Exceedances of the federal annual PM10 standa rd were confined to Riverside and San Bernardino counties, primarily in and ar ound the Metropolitan Rive rside county area. The more stringent state a nnual PM10 standard was exceeded in a much larger area, covering most of the Basin. The federal 24- hour PM10 standard was also exceeded at a few locations in the inland valley areas in 2001. The state 24-hour standard, however,

was exceeded at all locations monitored, with the Metropolitan Riverside county area exceeding most frequently (67% of sampli ng days). The maximum 24-hour average and annual PM10 concentrations (219 μg/m 3 

## and 63.1 μg/m 3 

## ) were 146% and 125% of the

federal 24-hour and annual sta ndards, respectively.

PM2.5 concentrations were monitored in th e District in 2001 in accordance with the adopted federal PM2.5 standards. Ma ximum 24-hour average and annual average PM2.5 concentrations (98.0 μg/m 3 

## and 31.1 μg/m 3 

## ) were 150% and 201% of the federal 24-hour and annual standards, respectively, both recorded in the Metropolitan Riverside
county area.



## Riverside County Salton Sea Air Basin (SSAB)

Pollutant concentrations in the Riverside county portion of SSAB were monitored at two locations in the Coachella Valley in 2001, a nd exceeded the federal and state standards

for ozone. No other standards were exceeded.

The highest 1-hour and 8-hour ozone concentrations record ed in the Coachella Valley in 2001 (0.137 ppm and 0.114 ppm) were 110% and 134% of the federa l 1-hour and 8-hour standards, respectively. The federal 1-hour ozone standard excee ded on a maximum of six days in SSAB in 2001. The more stringent state standard was exceeded on 42 days.

Both the state and federal 24-hour PM10 st andards and the stat e and federal annual

PM10 standards were exceeded in the Coache lla Valley. However, the deletion of highwind day samples from considera tion results in there being no exceedances of the federal

standards in 2001. PM2.5 c oncentrations were below th e federal 24-hour and annual

PM2.5 standards.



## Seasonal, Day-of-Week and Diurnal Variations

Concentrations of pollutants have been f ound to vary by season, day of week, and time of day, and these variati ons were examined for 1999- 2001 for ozone, carbon monoxide

and PM10. Ozone standard exceedances generally peak in summer, while carbon monoxide exceedances peak in late fa ll and winter, and federal 24-hour PM10 exceedances peak in fall and winter. Ozone tended to be higher on weekends than on weekdays, while the opposite was true for ca rbon monoxide and PM10. The time of the day which averaged highest in ozone conc entration was early afternoon in the peak

## Summary

II-S-3 ozone area, while carbon monoxide averaged hi ghest at the time of morning rush-hour

traffic.

# ATTACHMENT

## TABLE A

- 1

AMBIENT AIR QUALITY STANDARDS

CALIFORNIA FEDERAL

AIR POLLUTANT CONCENTRATION DISTRICT METHOD PRIMARY (>) SECONDARY (>) METHOD a)

Ozone b) 0.09 ppm, 1

- hour average > U.V. Photometry 0.12 ppm, 1

- hour average

0.08 ppm, 8

- hour avera ge b) Same as Primary

Standrd Chemiluminescence

Carbon Monoxide 9.0 ppm, 8

- hour average > c)
20 ppm, 1

- hour average > Gas Correlation 9 ppm, 8

- hour average d)
35 ppm, 1

- hour average None Non

- dispersive Infra

Red Spectrophotometry

Nitrogen Dioxide 0.25 ppm, 1

- hour average > e) Gas Phase

Chemiluminescence 0.053 ppm, annual average f) Same as Primary

Standrd Gas Phase

Chemiluminescence

Sulfur Dioxide 0.04 ppm, 24

- hour average > g)

0.25 ppm, 1

- hour average > h) Ultraviolet

PulseFluorescence 0.03 ppm, annua l average
0.14 ppm, 24

- hour average 0.50 ppm, 3

- hour

average Para

- rosaniline

Suspended

Particulate Matter (PM10)** 30 μ g/m 3 , annual geometric mean >

50 μ g/m 3 , 24

- hour average > i), **

20 μ g/m 3 , annual arithmetic mean >

** Size Segregation Inlet High Volu me Sampling 50 μ g/m 3 , annual arithmetic mean

150 μ g/m 3 , 24

- hour average j) Same as Primary

Standrd Inertial Separation and

Gravimetric Analysis

Suspended

Particulate

Matter (PM2.5) k), ** 12 μ g/m 3 , annual arithmetic mean ** Inertial Separation and

Gravim etric Analysis 15 μ g/m 3 , annual arithmetic mean

k)

65 μ g/m 3 , 24

- hour average k) Same as Primary

Standrd Inertial Separation and

Gravimetric Analysis

Lead 1.5 μ g/m 3 , 30

- day average >= High Vol. Sampling Atomic Absorption 1.5 μ g/m 3 , calendar quarter Same a s Primary

Standrd High Vol. Sampling

Atomic Absorption

Sulfates 25 μ g/m 3 , 24

- hour average >= High Vol. Sampling Ion Chouromatography

Hydrogen Sulfide 0.03 ppm, 1

- hour average >= Cadmium Hydroxide Stractan

Vinyl Chloride 0.010 ppm, 24

- hour average >= Gas Chouromatography

Visibility Reducing

Particles In sufficient amount to give an

extinction coefficient > 0.23 inverse kilometers (visual range less than 10 miles), with relative humidity <70%,

8

- hour average (10am

- 6pm, PST) l)

. Nep helometry and AISI Tape Sampler (COH) 

## NO

FEDERAL

STANDARDS

a) Reference method as described by the federal government. An equivalent method of measurement may be used as approved by the federal government.
b) Effective September 16, 1997, new federal 8

- hour average standard was established. c) Effective December 15, 1982. The previous standards were 10 ppm, 12

- hour average and 40 ppm, 1

- hour average. d) Effective September 13, 1985, standard changed from >10 μ g/m 3 (>=9.3 ppm) to > 9 ppm (>=9.5 ppm).
e) Effective March 9, 19 87, standard changed from >=0.25 ppm to > 0.25 ppm. f) Effective July 1, 1985, standard changed from > 100 μ g/m 3 (>0.0532 ppm) to > 0.053 ppm (>= 0.0535 ppm). g) Effective July 29, 1992. The previous standard was >= 0.05 ppm, 24

- hour average with ozone >= 0.1 ppm, 1

- hour average or TSP >=100 μ g/m 3 , 24

- hour average. h) Effective October 5, 1984. The previous standard was 0.5 ppm, 1

- hour average. i) Effective August 19, 1983**. The previous standards were annual geometric mean TSP > 60 μ g/m 3 , and 24 hour av erage TSP > 100 μ g/m 3

. j) Effective July 1, 1987. The previous standards were annual geometric mean TSP > 75 μ g/m 3 , and 24 hour average TSP > 260 μ g/m 3

. k) Effective September 16, 1997, new federal standards were established. There were no previous stand ards for PM2.5.** The new PM2.5 annual average state standard of 12 μg/m 3 and revised PM10 annual average state standard of 20 μg/m3 (to replace AGM 30 μg/m3) recommended by

the California Air Resources Board was approved by the state Office of Administr ative Law effective July 5, 2003

. l) Effective October 18, 1989. The previous standard was “In sufficient amount to reduce the prevailing visibility to less than 10 miles at relative humidity Revised
less than 70%, 1 observation”, and was based on human observation rather than instrumental measurement. July 2003

## TABLE A

- 2

Episode Criteria

SCAQMD AND CALIFORNIA FEDERAL

AIR POLLUTANT HEALTH ADVISORY ( ≥ ) STAGE I ( ≥ ) STAGE II ( ≥ ) STAGE III ( ≥ ) STAGE I ( ≥ )
(ALERT) STAGE II ( ≥ )

(WARNING) STAGE III ( ≥ )

(EME RGENCY)

Ozone 0.15 ppm, 1

- hr. avg. 0.20 ppm, 1

- hr. avg. 0.35 ppm, 1

- hr. avg. 0.50 ppm, 1

- hr. avg. 0.2 ppm, 1

- hr. avg. 0.4 ppm, 1

- hr. avg. 0.5 ppm, 1

- hr. avg.

Carbon Monoxide 40 ppm, 1

- hr. avg.
20 ppm, 12

- hr. avg. 75 ppm, 1

- hr. avg.

35 ppm, 12

- hr. avg. 1 00 ppm, 1

- hr. avg.

50 ppm, 12

- hr. avg. 15 ppm, 8

- hr. avg. 30 ppm, 8

- hr. avg. 40 ppm, 8

- hr. avg.

Nitrogen Dioxide 0.6 ppm, 1

- hr. avg.
0.15 ppm, 24

- hr. avg 1.2 ppm, 1

- hr. avg.

0.30 ppm, 24

- hr. avg. 1.6 ppm, 1

- hr. avg.

0.40 ppm, 24

- hr. avg.

Sulfur Dioxi de 0.50 ppm, 1

- hr. avg.
0.20 ppm, 24

- hr. avg. 1.00 ppm, 1

- hr. avg.

0.70 ppm, 24

- hr. avg. 2.00 ppm, 1

- hr. avg.

0.90 ppm, 24

- hr. avg. 0.3 ppm, 24

- hr. avg. 0.6 ppm, 24

- hr. avg. 0.8 ppm, 24

- hr. avg.

Suspended Particulate

(PM 10 ) 350 μg/m 3 , 24

- hr. avg. 42 0 μg/m 3 , 24

- hr. avg. 500 μg/m 3 , 24

- hr. avg.

Suspended Particulate

(PM 2.5 )

Sulfates* 25 μg/m 3 , 24

- hr. avg. combined with ozone > 0.20 ppm, 1

- hr. avg.

Actions to be Taken** Health Advisory to

a) Persons with
respiratory and
coronary disease,
b) School officials in

order to curtail students'
participation in strenuous

activities. First steps in
abatement plans.
Health Advisory to
a) Persons with
respiratory and
coronary disease,
b) School officials

in order to curtail
students' participation

i n strenuous activities. Intermediate Steps.

Abatement actions

taken to reduce

concentration of
pollutant at issue. Mandatory abatement

measures. Extensive

actions taken to

prevent exposure at

indicated levels.

State can take

action if local efforts

fail ed. Open burning

prohibited. Reduction
in vehicle operation
requested. Industrial

curtailment. Incinerator use

prohibited. Reduction
in vehicle operation
required. Further

industrial curtailment. Vehicle use prohibited.

Industry shut down or

curtailment . Public

activities ceased.

* Episodes based upon these criteria are not classified according to stages.

** For ozone, actions a) and b) are taken at Health Advisory level. For all other pollutants, these actions are taken at Stage I Episode level.

## TABLE A

- 3

Air Monitoring Stations and Source/Receptor Areas

AIR

SOURCE/RECEPTOR MON

AREA # AREA* STN #

LOS ANGELES COUNTY

1 Central LA 087

2 Northwest Coastal LA County 091

3 Southwest Coastal LA County 094

4 South Coastal LA Coun ty 072

6 West San Fernando Valley 074

7 East San Fernando Valley 069

8 West San Gabriel Valley 088

9 East San Gabriel Valley 1 060

9 East San Gabriel Valley 2 591

10 Pomona/Walnut Valley 075

11 South San Gabriel Valley 085

12 South Cen tral LA Co unty 1 084

12 South Central LA County 2 801

13 Santa Clarita Valley 0 90

ORANGE COUNTY

16 North Orange County 3177

17 Central Orange County 3176

18 North Coastal Orange County 3195

19 Saddleback Valley 1 3186

19 Saddleback Valley 2 3812

RIVERSIDE COUNTY

22 Norco/Corona 4155

23 Metropolitan Riverside Co unty 1 4144

23 Metropolitan Riverside County 2 4146

24 Perris Valley 4149

25 Lake Elsinore Area 4158

29 Banning Airport 4164

30 Coachella Valley 1** 4137

30 Coachella Vall ey 2** 4157

SAN BERNARDINO COUNTY

32 Northwest San Bernardino Valley 5175

33 Southwest San Bernardino Valley 5 817

34 Central San Bernardino Valley 1 5197

34 Central San Bernardino Valley 2 5203

35 East San Bernardino Valley 5204

37 Central San Ber nardino Mountains 5181

3 8 East San Bernardino Mountains 5 818

* Source/Receptor areas and numbers are shown in detail on the map "South Coast Air Quality Management

District and Air Monitoring Areas" which is available from SCAQMD Public Information

. **Salton Sea Air Basin.

### L o s A n g e l e s C o u n t y

O r a n g e C o u n t y S a n B e r n a r d i n o C o u n t y

R i v e r s i d e C o u n t y

M I L E S 0 2 5 

### 1 9

2 1 2 5 2 2

2 6

2 4 2 3 3 2 3 6 3 7 3 8

3 0

2 8 2 9

2 7 2 0 1 8 3 3 3 4

3 5

1 7 4 1 6 1 0 1 1

5 1 2

3 9

8 7 6

1 2 1 3 1 5 1 4

# # S O U T H C O A S T
A I R B A S I N (

S C A B )

C O U N T Y L I N E S

A R E A L I N E S

A I R M O N I T O R I N G S T A T I O N

A R E A N U M B E R

A P R I L 1 9 9 5 V E R S I O N S C A Q M D
A I R M O N I T O R I N G N E T W O R K



## FIGURE A

- 1 South Coast Air Basin and Adjoining Areas of Salton Sea Air BasinTABLE A-4Ozone - Number of Days Exceeding theFederal Standard (12 pphm, 1-Hour Average)STN# LOCATION 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:060 East San Gabriel Valley 1 129 137 155 146 129 137 104 123 129 117 126 111 125 112 84 73 91 79 72 63 26 11 19 2* 11 9069 East San Fernando Valley 138 75 102 92 99 91 63 95 73 87 93 76 64 40 40 55 47 16 18 20 6 2 7 0 3 2072 South Coastal Los Angeles County 3 4 8 12 6 13 6 16 13 11 10 4 7 3 0 0 6 1 1 0 0 0* 0 10 0074 West San Fernando Valley 122 126 68 103 98 96 66 67 78 75 72 60 71 54 41 53 25 32 7 8 11 0 7 0 0 2075 Pomona/Walnut Valley 1 108 120 136 126 99 97 66 102 98 98 89 72 91 61 60 60 56 45 47 47 16 7 18 2 3 1076 Southwest Coastal Los Angeles County 9 4 13 7 0 4 2 9 8 4* a) -- -- -- -- -- -- -- -- -- -- -- ---- -- --080 Southeast Los Angeles County 70 53 65* 47 40 56 44 67 60 58 39 40 29 37 21 23 32 12 -- -- -- -- -- -- -- --084 South Central Los Angeles County 1 18* 3* 16 26 14* 15 13 27 22 16 16 11 12 7 3 1 4 0 0 0 1 0 00 0 0085 South San Gabriel Valley 69* 130 120 110 107 94 66 98 92 79 79 63 67 61 43 48 45 33 21 20 32 6 10 0 2 1087 Central Los Angeles 71 58 55 50* 59 74 48 69 53 56 48 36 24 34 32 23 23 8 14 5 24 0 5 1 1 0088 West San Gabriel Valley 129 134 152 151 118 116 89 122 125 116 110 95 119 80 69 70 71 53 61 44 54 5 14 0 7 1090 Santa Clarita Valley 120 132 121 140 96 123 94 85 86 93 87 67 107 71 62 65 71 44 66 26 68 13 16 0 1 9091 Northwest Coastal Los Angeles County 32 14 34* 44 35 40 20 37 35 37 30 16 16 15 8 9 12 7 2 1 13 0 1 0 0 0094 Southwest Coastal Los Angeles County -- -- -- -- -- -- -- -- -- -- 8 3 5 3 0 0 1 1 0 0 1 0 0 1 0 0108 Pomona/Walnut Valley 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 44* 26 23 2* -- -- -- -- --591 East San Gabriel Valley 2 -- -- -- -- -- 135 126 134 130* 141 148 135 148 121 103 91 118 96 88 73 49 18 28 3 11 13801 South Central Los Angeles County 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 1* 1* 0* --ORANGE COUNTY:3176 Central Orange County 1 26* 14* 51 27 39 32 28 40 37 35 28 25 19 13 11 11 22 3 5 2 1 0 2 0* 1 0*3177 North Orange County 32 37 69 62 63 60 39 64 59 57 49 41 33 36 35 28 31 13 9 4 5 1 5 0 1 03186 Saddleback Valley 1 26 17* 33 24 25 18 18 24 26 30 12 16 18 7 11 10 9 7 5 1 2 2 2 0 1* --3190 Central Orange County 2 20 18* 39 17 13 13 10 16 12 11 5 4 17 11 7 10 9 4 -- -- -- -- -- -- -- --3195 North Coastal Orange County 3 6* 25 16 5 6 6 15 7 17 10 2 1* -- 3 5 3 1 0 0 1 0 0 0 0 03812 Saddleback Valley 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 2* 1RIVERSIDE COUNTY:4137 Coachella Valley 1** 33* 51 57 49* 49 57 37 40 36 25 31 33 35 37 27 22 21* 20 13 9 12 4* 8 1 0 64141 Hemet/San Jacinty Valley 17 31 20* -- -- -- -- -- -- 13 9 27 28 21 20 23 5 8 13 2 0* -- -- -- -- --4144 Metropolitan Riverside County 141 152 139 151 132 127 96 121 127 125 106 113 123 112 90 79 75 71 77 52 36 13* 32 3 374149 Perris Valley 109 132 109 118 103 118 90 88 75 96 79 82 82 78 62 71 83 73 59 36 31 6 8 0 15 194150 Banning/San Gorgonio Pass 37* 62 79 84 76 50 58 67 48 55 45 53 64 60 43 31 19 8 25 15 11 2 0* b) -- --4155 Norco/Corona 102 116 113 114 99 101 67 97 85* 92 77 73 61 56 13 54 16 17 14 23 2* -- -- -- -- --4157 Coachella Valley 2** -- 35 37 16 -- 30 18 33 19 16 -- -- -- 16 10 13 8 3 0 3 0 0 2 1 0 04158 Lake Elsinore 55 74 45* -- -- -- -- -- -- -- -- -- -- 62 36 45 24 27 27 23 17 4 22 5 1 124163 Temecula Valley -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 2 1 0* 0 0* 0* -- -- -- --4164 Banning Airport -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 25 5 4 16SAN BERNARDINO COUNTY:5175 Northwest San Bernardino Valley 139* 151* 138* 135 131 139* 113* 120 115 110 111 101 122 97 64 67 81 55 79 67 35 12 30 4 10 145181 Central San Bernardino Mountains 47* 142 123 139 125 131 121 117 139 114 117 119 128 127 103 90 103 88 107 65 62 29 5730 17 265197 Central San Bernardino Valley 1 145 160 155 164 146 147 96 127 136 126 121 116 124 112 92 74 88 65 91 57 38 10 32 4 7 135203 Central San Bernardino Valley 2 112 139 138 140 130 134 111 117 125 111 108* 117 121 115 78 79 85 65 96 61 63 32 39 14 7185204 East San Bernardino Valley 1 96 123 136 139 127 116 103 109 116 113 93 120 130 116 81 91 103 95 98 69 65 35 43 12 1121*District Maximum145 160 155 164 146 147 126 134 139 141 148 135 148 127 103 91 118 96 107 73 68 35 57 30 17 26a) Station relocated in 1986.b) Station relocated in 1998.* Less than 12 full months of data** Salton Sea Air BasinTABLE A-5Ozone, 1976-2001Annual Number of Days of First/Second Stage Episodes(Days Maximum 1-Hour Average Ozone≥0.20 ppm/≥0.35 ppm)STN# LOCATION 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001060 East San Gabriel Valley 147/1 64/0 76/5 71/10 74/7 65/2 40/1 63/3 55/0 48/1 45/0 26/0 33/0 30/0 13/0 12/0 16/0 11/0 2/0 3/0 1/0 0/0 1/0 0/0* 0/0 0/0069 East San Fernando Valley43/1 11/0 30/0 26/2 30/1 18/0 12/0 34/0 5/0 17/0 14/06/0 4/0 5/0 1/0 4/0 8/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0072 South Coastal Los Angeles County0/0 0/0 0/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0* 0/0 0/0 0/0 0/0 0/0074 West San Fernando Valley33/0 37/0 16/0 24/0 36/1 12/0 4/0 11/0 6/0 9/0 5/0 2/0 4/0 5/0 0/0 2/0 0/0 0/0 0/0 0/0 1/0 0/0 0/0 0/0 0/0 0/0075 Pomona/Walnut Valley 137/1 58/0 72/9 57/3 49/1 32/0 31/0 45/0 30/0 32/0 24/0 16/0 16/0 10/0 12/0 8/0 10/0 6/0 3/0 2/0 0/0 0/0 0/0 0/0 0/0 0/0080 Southeast Los Angeles County19/1 12/0 18/1* 16/0 5/0 18/0 7/0 23/0 17/0 11/0 4/0 4/0 5/0 4/0 0/0 0/0 1/0 0/0 -- -- -- -- -- -- -- --084 South Central Los Angeles County2/0* 0/0* 0/0 6/0 0/0* 1/0 2/0 3/0 4/0 1/0 1/0 1/0 1/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0085 South San Gabriel Valley26/1* 52/0 48/5 38/3 38/1 28/0 18/1 35/0 24/0 19/0 18/0 7/0 12/0 16/0 0/0 6/0 5/0 0/0 2/0 0/0 0/0 0/0 0/0 0/0 0/00/0087 Central Los Angeles11/0 3/0 16/0 14/0 10/0 8/0 7/1 12/0 8/0 9/0 8/0 2/0 2/0 1/0 2/0 0/0 1/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0088 West San Gabriel Valley51/0 55/0 85/8 78/11 56/3 48/0 33/1 59/0 49/0 41/1 33/0 15/0 18/0 17/0 7/0 10/0 10/0 5/0 2/0 1/0 0/0 0/0 0/0 0/0 0/0 0/0090 Santa Clarita Valley38/0 59/0 45/0 59/0 46/2 37/0 17/0 19/0 18/0 15/0 15/02/0 28/0 11/0 6/0 8/0 4/0 3/0 6/0 1/0 0/0 0/0 0/0 0/0 0/00/0091 Northwest Coastal Los Angeles County4/0 0/0 10/0* 7/0 3/0 3/0 3/0 6/0 5/0 4/0 1/0 1/0 2/0 1/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0094 Southwest Coastal Los Angeles County1/0 0/0 2/0 0/0 0/0 0/0 0/0 0/0 1/0 0/0 0/0 1/0 1/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0108 Pomona/Walnut Valley 2-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 3/0* 2/0 0/0 0/0* -- -- -- -- --591 East San Gabriel Valley 2-- -- -- -- 30/5* 61/2 62/2 74/2 67/0* 68/5 70/1 51/0 54/0 37/0 29/0 34/0 30/0 19/0 10/0 9/0 2/0 0/0 3/0 0/0 0/0 0/03176 Central Orange County 14/0* 0/0* 13/0 5/0 6/0 5/0 7/0 10/0 5/0 11/0 1/03/0 3/0 4/0 0/0 2/0 1/0 0/0 1/0 0/00/0 0/0 0/0 0/0* 0/0 0/0*3177 North Orange County15/0 8/0 24/1 21/1 14/0 15/0 12/0 15/0 15/0 13/0 8/06/0 3/0 5/0 4/0 1/0 1/0 0/0 2/0 0/00/0 0/0 0/0 0/0 0/0 0/03186 Saddleback Valley3/0 2/0* 10/0 6/0 3/0 5/0 3/0 10/0 3/0 7/0 1/01/0 2/0 2/0 0/0 1/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0* --3188 Capistrano Valley2/0* 1/0 2/0* -- -- -- -- -- -- -- -- -- -- 0/0* -- -- -- -- -- -- -- -- -- -- -- --3190 Central Orange County 22/0 0/0* 5/0 2/0 3/0 0/0 2/0 2/0 0/0 0/0 0/0 0/0 1/0 0/0 0/0 0/0 0/0 0/0 -- -- -- -- -- -- -- --3191 North Orange County17/0 10/0 9/0 14/2 13/0 4/0* -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --3195 North Coastal Orange County0/0 0/0* 3/0 1/0 0/0 1/0 0/0 2/0 1/0 1/0 0/00/0 0/0* -- 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/04137 Coachella Valley 1**3/0* 5/0 3/0 3/0* 4/0 0/0 0/0 0/0 1/0 2/0 0/00/0 1/0 0/0 0/0 0/0 0/0 0/0 0/0 0/00/0 0/0* 0/0 0/0 0/0 0/04141 Hemet/San Jacinty Valley0/0 2/0 2/0* -- -- -- -- -- -- 1/0 0/0 0/0 0/0 0/0 1/0 0/0 0/0 0/0 0/0 0/0 0/0* -- -- -- -- --4144 Metropolitan Riverside County46/2 66/1 62/2 55/0 67/4 34/0 26/0 42/1 29/0 35/1 19/0 20/0 16/0 18/0 15/0 17/0 6/0 5/0 2/0 3/0 1/0 0/0* 1/0 0/0 0/00/04149 Perris Valley13/0 39/0 38/0 26/0 20/0 18/0 10/0 13/0 6/0 8/0 3/01/0 1/0 4/0 0/0 5/0 1/0 3/0 0/0 1/00/0 0/0 0/0 0/0 0/0 0/04150 Banning/San Gorgonio Pass20/0* 13/0 22/0 22/0 13/0 7/0 3/0 12/0 5/0 8/01/0 3/0 7/0 6/0 4/0 1/0 0/0 0/0 1/0 0/0 0/0 0/0 0/0* -- -- --4155 Norco/Corona26/0 31/1 34/2 24/0 32/0 24/1 15/1 29/1 19/0* 20/1 12/0 9/0 7/0 3/00/0 7/0 1/0 0/0 0/0 0/0 0/0 -- -- -- -- --4157 Coachella Valley 2**0/0* 0/0 0/0 1/0 0/0 0/0 0/0 0/0 0/0 1/0 -- 0/0 -- 0/0 0/0 0/0 0/00/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/04158 Lake Elsinore1/0 10/0 7/0* -- -- -- -- -- -- -- -- -- 0/0* 4/0 0/0 1/0 0/0 0/0 0/00/0 0/0 0/0 0/0 0/0 0/0 0/04163 Temecula Valley-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 0/0 0/0 0/0* 0/0 0/0* 0/0* -- -- -- --5175 Northwest San Bernardino Valley61/1* 85/2* 68/2* 59/2 73/4 62/1 0/0* 59/1* 41/0 39/038/0 23/0 25/1 19/0 12/0 14/0 15/0 7/0 7/0 6/0 2/0 0/0 1/0 0/00/0 0/05181 Central San Bernardino Mountains11/0* 63/0 73/0 80/3 54/0 49/1 29/0 48/0 49/0 41/034/0 22/0 38/0 30/0 16/0 15/0 22/0 5/0 12/0 6/0 4/0 1/0 10/0 0/0 0/0 0/05182 East San Bernardino Valley 228/0 39/0 56/0 0/0* 67/0 19/0* -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --5197 Central San Bernardino Valley 169/1 98/6 98/11 95/9 84/6 73/1 34/0 56/0 45/0 48/0 42/0 28/0 23/0 28/0 20/0 16/0 19/0 5/0 9/0 2/0 1/0 0/0 1/0 0/0 0/0 0/05198 Southwest San Bernardino Valley39/1 42/3 22/2* -- -- -- -- -- -- 15/0 14/0 0/0 -- -- -- -- -- -- -- -- -- -- -- -- -- --5203 Central San Bernardino Valley 251/0 70/1 72/1 62/0 72/2 58/1 38/0 49/0 36/0 30/0 41/0* 27/0 31/0 22/0 8/0 9/0 17/0 4/0 7/0 4/0 2/0 1/0 1/0 0/0 0/00/05204 East San Bernardino Valley 125/1 48/0 64/2 57/0 61/0 20/0 30/0 41/0 26/0 31/0 22/0 26/0 25/0 17/0 11/0 16/0 7/0 8/0 8/0 4/0 1/0 1/0 1/0 0/0 0/00/0** Less than 12 full months of data.** Salton Sea Air Basin.TABLE A-6Ozone - Annual Maximum 1-Hour, ppm 1955-2001LOCATION 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977087 Central Los Angeles .68 .47 .53 .61 .61 .41 .45 .50 .50 .46 .58 .50 .36 .46 .30 .33 .24 .25 .52 .25 .25 .34 .21060 East San Gabriel Valley1 - - .42 .45 .56 .49 .45 .43 .34 .40 .54 .53 .65 .44 .54 .58 .48 .49 .46 .38 .32 .38 .32069 East San Fernando Valley.30* .33 .43 .39 .47 .33 .33/.33 .38 .39 .40 .32 .47 .42 .38 .35 .31 .28 .29 .35 .27 .35 .31091 Northwest Coastal Los Angeles County- - - - - - - .40* .40 .32 .39 .29 .36 .44 .30 .24 .26 .19 .39 .19 .19 .28 .18/072 South Coastal Los Angeles County- - - .37 .30 .37 .34 .33/.28 .27 .34 .27 .21 .33 .22 .18 .27 .17 .20 .27 .14 .16 .15074 West San Fernando Valley- - - - - - - - - - .47 .44 .41 .34 .39 .37 .32 .29 .28 .28 .30 .27 .34075 Pomona/Walnut Valley1 - - - - - - - - - - .44* .44 .43 .49 .45 .48 .35 .37 .32 .31 .33 .36 .32076 Southwest Coastal Los Angeles County- - - - - - - - - - .32 .37 .33 .23 .25 .23 .21 .17 .24 .15 .18 .22 .17094 Southwest Coastal Los Angeles County- - - - - - - - - - - - - - - - - - - - - - -080 Southeast Los Angeles County- - - - - - - - - - - - - - .43* .36 .39 .29 .28 .35 .25 .37 .30090 Santa Clarita Valley- - - - - - - - - - - - - - .20 .41 .30 .29 .36 .26 .30 .33 .33088 West San Gabriel Valley- .46 .36/.44* .47 .54 .44 .46 .41 .42 .46 .43 .40/.48* .52 .51 .53 .38* .45 .34 .32 .34 .32084 South Central Los Angeles County1 - - - - - - - - - - - - - - - - - .22* .28 .19 .24 .24801 South Central Los Angeles County2 - - - - - - - - - - - - - - - - - - - - - - -085 South San Gabriel Valley- - - - - - - - - - - - - - - - - - - - - .35 .32591 East San Gabriel Valley2 - - - - - - - - - - - - - - - - - - - - - - -3176Central Orange County 1--------.27.23.41.31.30.28.30.29.34.28.26.24.13*.30.193177 North Orange County1 - - - - - - - - - - - - .23* .26 .43 .30 .34 .32 .30 .44 .28 .30 .253195 North Coastal Orange County- - - - - - - - - - - - - - - - - .19 .21 .22 .18 .16 .183186 Saddleback Valley1 - - - - - - - - - - - - - - - - - - .19 .38 .19 .23 .203812 Saddleback Valley2 - - - - - - - - - - - - - - - - - - - - - - -3188 Capistrano Valley- - - - - - - - - - - - - - - - - - .20 .25 .18 .20 .223190 Central Orange County2 - - - - - - - - - - - - - - - - - .14 - .27 .21 .26 .183191 North Orange County2 - - - - - - - - - - - - - - - - - - - .11 .33 .33 .304137Coachella Valley 1** - - - - - - - - - - - - - - - -.31.25.25.24.21.22.214157 Coachella Valley2** - -- - - - - - - - - - - - - - .26 .20 .17 .18 .20 .16 .194155 Norco/Corona - -- - - - - - - - - - - - - - .05* .30 .35 .31 .15* .33 .364141 Hemet/San Jacinto Valley- - - - - - - - - - - - - - - - - - .22 .20 .18 .19 .254144 Metropolitan Riverside County1 - - - - - - - - .28 .40 .29 .31 .40 .34* - - .45 .40* .31 .32 .35 .36 .354149 Perris Valley- - - - - - - - - - - - - - - - - - .27* .26 .27 .22 .284150 San Gorgonio Pass - - - - - - - - - - - - - - - .37 .19 .26 .32* .24 .27 .28 .274164 BanningAirport- - - - - - - - - - - - - - - - - - - - - - -4163 Temecula Valley- - - - - - - - - - - - - - - - - - - .15 .18 .21 .174158 Lake Elsinore - -- - - - - - - - - - - - - - - - - .23* .30 .20 .235203Central San Bernardino Valley 2--------.28.32.32.31.33.28.27.36.26.34.34.27.38.32.375204 East San Bernardino Valley- - - - - - - - - - - - .12* .32 .30 .42 .28 .31 .34 .31 .32 .35 .335171 Southwest San Bernardino Valley- - - - - - - - - - - .32* .21 .21 .22 .08* - - .36 .34 .33 .36 .375175 Northwest San Bernardino Valley- - - - - - - - - - - - - - - - - - .48 .51 .39 - -5174 Northwest San Bernardino Valley(ARB)- - - - - - - - - - - - - - - - - - .51 .44 .41 .38* .385197 Central San Bernardino Valley1 - - - - - - - - - - - - - - - - - - .42* .49 .38 .38 .395177 Central San Bernardino Mountains 2 - -- - - - - - - - - - - - - - - - .13* .27 .14* .15 .225181 Central San Bernardino Mountains 1 - -- - - - - - - - - - - - - - - - .13* .26* .27 .23 .32District Maximum.68 .47 .53 .61 .61 .54 .45 .50 .50 .46 .58 .53 .65 .49 .54 .58 .53 .49 .52 .51 .41 .38 .39* Incomplete data. / Station location change**Salton Sea Air BasinTABLE A-6(continued)Ozone - Annual Maximum 1-Hour, ppm 1955-2001LOCATION 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001087 Central Los Angeles .30 .31/.29 .32 .40 .26 .29 .30 .22 .22 .21 .25 .20 .19 .20 .16 .19 .17 .14 .12 .15 .13 .14 .12060 East San Gabriel Valley1 .40 .45 .41 .35 .36 .39 .31 .36 .31 .30 .30 .33 .23 .28 .27 .24 .25 .21 .20 .16 .20 .14 .17 .19069 East San Fernando Valley.30 .39 .35 .27 .25 .31 .26 .30 .28 .23 .24 .20 .20 .22 .22 .18 .17 .17 .14 .13 .18 .12 .15 .13091 Northwest Coastal Los Angeles County.24/.26 .21 .23 .28 .23 .27/.27 .20 .28 .24 .25 .16 .18 .17 .18 .16 .14 .14 .11 .13 .12 .10 .10072 South Coastal Los Angeles County.19 .21 .20 .23 .22 .30 .27 .23 .18 .17 .16 .16 .12 .11 .15 .14 .16 .11 .11 .10 .12 .13 .12 .09074 West San Fernando Valley.27 .33 .38 .25 .22 .26 .26 .25 .22 .22 .25 .23 .19 .22 .17 .19 .14 .15 .21 .12 .16 .10 .11 .14075 Pomona/Walnut Valley1 .41 .35 .37 .33 .31 .34 .31 .33 .27 .29 .29 .25 .24 .24 .26 .21 .24 .22 .19 .16 .18 .14 .15 .14076 Southwest Coastal Los Angeles County.30 .19 .11 .19 .16 .18 .22 .17/- - - - - - - - - - - - - - -094 Southwest Coastal Los Angeles County- - - - - - - - .19 .20 .22 .19 .10 .11 .15 .13 .11 .12 .13 .11 .09 .15 .10 .10080 Southeast Los Angeles County.36 .32 .27 .27 .31 .32 .30 .32 .25 .23 .29 .26 .19 .19 .22 .19 - - - - - - - -088 West San Gabriel Valley.42 .44 .41 .33 .37/.34 .30 .37 .26 .28 .29 .27 .26 .23 .27 .22 .26 .21 .17 .14 .17 .12 .16 .16090 Santa Clarita Valley.32 .32 .36 .29 .26/.29 .27 .24 .24 .21 .30 .25 .23 .24 .22 .22 .26 .21 .17 .16 .18 .12 .13/.18084 South Central Los Angeles County1 .18 .29 .18 .21 .26 .23 .27 .21 .20 .24 .21 .14 .15 .16 .17 .12 .12 .09 .10 .08 .09 .12 .09 .08801 South Central Los Angeles County2 - - - - - - - - - - - - - - - - - - - - .13* .11* .12* -085 South San Gabriel Valley.43 .39 .39 .35 .39 .33 .27 .31 .24 .28 .30 .26 .19 .26 .26 .19 .22 .18 .14 .13 .18 .12 .14 .13591 East San Gabriel Valley2 - - .49 .39 .36 .38 .34 .39 .35 .33 .34 .34 .29 .32 .30 .28 .30 .22 .21 .17 .22 .14 .17 .193176Central Orange County 1.29.33.28.26.26.30.25.25.20.22.27.24.18.25.22.17.21.13.13.10.11.10*.13.113177 North Orange County1 .35 .38 .31 .27 .32 .27 .32 .34 .25 .24 .29 .26 .21 .21 .21 .19 .25 .16 .15 .13 .18 .12 .14 .113195 North Coastal Orange County.22 .21/.16 .20 .18 .25 .25 .21 .17 .16 .13 - .15 .17 .15 .13 .12 .11 .10 .10 .12 .10 .10 .103186 Saddleback Valley1 .34 .32 .34 .33 .27 .29 .30 .28 .23 .20 .21 .23 .19 .24 .16 .16 .18 .15 .14 .13 .16 .10 .13 -3812 Saddleback Valley2 - - - - - - - - - - - - - - - - - - - - - - .15 .133188 Capistrano Valley.32 - - - - - - .19 - - - .15* -- - - - - - - - - - -3190 Central Orange County2 .27 .26 .22 .18 .23 .20 .19 .19 .15 .17 .23 .16 .17 .17 .18 .15 - - - - - - - -3191 North Orange County2 .27 .39 .33 .23* - - - - - - - - - - - - - - - - - - - -4137Coachella Valley 1**.20.24.21.19.19.19.20.24.18.17.20.19.17.18.15*.17.17.16.16.16.17.13.12.144157 Coachella Valley2 ** .17 .21 .11 .18 .17 .18 .19 .20 - .16 - .16 .16 .18 .14 .16 .12 .14 .12 .11 .13 .13 .11 .114155 Norco/Corona .40 .33/.34 .37 .35 .35 .30 .35 .27 .24 .25 .23 .17 .22 .23 .16 .17 .19 .16 - - - - -4141 Hemet/San Jacinto Valley.27 - - - - - .18* .23 .18 .18 .18 .19 .22 .19 .15 .18 .16 .15 .12 - - - - -4144 Metropolitan Riverside County.39 .34 .37 .30 .31 .36 .32 .35 .25 .29 .28 .27 .29 .24 .26 .26 .25 .21 .20 .19 .20 .14 .14 .144149 Perris Valley.32 .25 .29 .24 .28 .26 .22 .29 .22 .20 .23 .21 .19 .20 .21 .20 .18 .20 .18 .14 .15 .11 .16 .154150 San Gorgonio Pass .30 .27 .26 .23 .24 .26 .25 .29 .22 .21 .26 .23 .22 .20 .16 .16 .20 .18 .19 .13 .12/- - -4164 BanningAirport- - - - - - - - - - - - - - - - - - - - .17 .14 .14 .154163 Temecula Valley.23 - - - - - - - - - - - - .17* .13 .13 .10* .11 .10 .10* - - - -4158 Lake Elsinore .30 -- - - - - - - - - .24 .19 .20 .17 .19 .19 .19 .15 .16 .17 .14 .13 .155203Central San Bernardino Valley 2.36.34.36.36/.30.32.30.27/.30.25.28.30.29.25.28.21.25.20.24.20.21.16.15.185204 East San Bernardino Valley.39 .34/.32 .24 .29 .30 .29 .33/.29 .24 .29 .27 .30 .25 .27 .27 .23 .24 .22 .20 .22 .15 .15 .17*5171 Southwest San Bernardino Valley.36 - - - - - .32* .32 .25 - - - - - - - - - - - - - - -5175 Northwest San Bernardino Valley- - - - - .36 .32 .33 .29 .28 .35 .32 .29 .27 .28 .24 .25 .24 .22 .19 .21 .15 .18 .175174 Northwest San Bernardino Valley(ARB).35 .37 .44 .36 - - - - - - - - - - - - - - - - - - - -5197 Central San Bernardino Valley1 .42 .42 .42 .35/.31 .32 .32 .34 .31 .29 .29 .32 .27 .29 .28 .24 .25 .22 .22 .17 .20 .14 .17 .175177 Central San Bernardino Mountains 2 .17 -- - - - - .26 - - - - - - - - - - - - - - - -5181 Central San Bernardino Mountains 1 .33 .40 .31 .35 .32 .28.34 .30 .26 .29 .29 .27 .33 .27 .28 .24 .27 .26 .20 .21 .24 .17 .18 .17District Maximum.43 .45 .49 .39 .40 .39 .34 .39 .35 .33 .35 .34 .33 .32 .30 .28 .30 .26 .24 .21 .24 .17 .18 .19* Incomplete data. / Station location change**Salton Sea Air BasinTABLE A-7Carbon Monoxide - Number of Days Maximum 8-Hour AverageExceeded the Federal Standard (≥9.5 ppm)STN# LOCATION 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:060 East San Gabriel Valley 1 3 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0069 East San Fernando Valley 100 72 54 54 60 4836 21 18 18 16 14 15 21 10 8 3 0 5 4 0* 0 0 0 0 0072 South Coastal Los Angeles County 52 41* 31 208 3 4 8 1 5 4 0 1 2 0 0 0 0* 0 0 0* 0 0 0 0 0074 West San Fernando Valley 52 45 47 28 2830 26 17 8 10 12 2 4 13 12 9 1 0 4 2 0 1 0 0 1 0075 Pomona/Walnut Valley 6 9 6 1 4 3 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0076 Southwest Coastal Los Angeles County 83 62 6250 67 46 44 40 58 45 a) -- -- -- -- -- -- -- -- -- -- -- -- --080 Southeast Los Angeles County 41 33 28 18*19 10 10 6 0 4 0 1 0 0 0 0 0 0 -- -- -- -- -- --084 South Central Los Angeles County 1 107 83 79 64 65 54 44 29 49 32 43 38 55 61 42 37 31 22 22 13 20 14 10 8 2 0085 South San Gabriel Valley 24* 41 39 26 196 4 5 0 4 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0087 Central Los Angeles 64 53 36 14 16 16 9 11 0 2 2 2 4 1* 2 0 2 0 0 0 0 0 0 0 0 0088 West San Gabriel Valley 34 27 26 21 22 19 14 10 0 5 2 3 4 0 2 1 0 0 0 0 0 0 0 0 0 0090 Santa Clarita Valley 0 2 0 0 -- -- -- -- -- -- -- -- -- 0* 0 0 0 0 0 0 0 0 0 0 0 0091 Northwest Coastal Los Angeles County 53 3319* 27 34 21 19 11 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0094 Southwest Coastal Los Angeles County -- ---- -- -- -- -- -- -- -- 16 15 25 24 10 7 7 3 5 0 5 1 0 0 0 0801 South Central Los Angeles County 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 8* 6 1* --ORANGE COUNTY:3176 Central Orange County 60 30 21 31 44 17 1 4 4 3 1 0 5 6 2 0 0 0 0 0 0 0 0 0* 0 0*3177 North Orange County 70* 50 17 18 19* 10 10 8 1 6 2 3 3 7 1 0 0 0 0 0 0 0 0 0 0 03186 Saddleback Valley 1 -- -- -- -- -- 0* 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0* --3195 North Coastal Orange County 55 15 7 16 6 5 2 1 1 5 3 0 2 6* 4 0 0 0 0 0 0 0 0 0 0* 03812 Saddleback Valley 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 0* 0RIVERSIDE COUNTY:4137 Coachella Valley 1** 0* 0 0 0* 0 0 0 0 0 0 0 0 0 0 0 0 0* 0 0 0 0 0 0 0 0 04144 Metropolitan Riverside County 1 0 1 0 0 00 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0* 0 0 0 04146 Metropolitan Riverside County 2 1* -- -- -- -- -- -- 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0* 0 04149 Perris Valley 0* 0* 0 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4150 San Gorgonio Pass 0* 0 0 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4155 Norco/Corona 0 1* 0* 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4157 Coachella Valley 2** 0* 0* 0 0* -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 0* --4158 Lake Elsinore -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 0 0SAN BERNARDINO COUNTY:5175 Northwest San Bernardino Valley 0* 0* 0 0 0 0* -- 2 0 0 0 0 0 0 0 0* -- -- -- -- -- -- -- -- 0 05181 Central San Bernardino Mountains 0* 0* 0 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --5197 Central San Bernardino Valley 1 0 0* 1 10* 0 0 0 0 0 0 0 0 0 0 0* -- -- -- -- -- -- -- -- -- --5203 Central San Bernardino Valley 2 0 2* 0 0 0 0 00 0 0* 0* 0 0 0 0 0 0 0 0 0 0 0* 0 0 0* 05204 East San Bernardino Valley 1 0 0 0 0 0 0 0 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --a) Station relocated in 1986.* Incomplete data** Salton Sea Air BasinTABLE A-8Carbon Monoxide - Number of Days Maximum 8-Hour AverageExceeded the Federal Alert Level (> 15 ppm)STN# LOCATION 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:060 East San Gabriel Valley 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0069 East San Fernando Valley 30 12 6 3 12 11 9 4 0 2 1 0 0 0 0 0 0 0 0 0 0* 0 0 0 0 0072 South Coastal Los Angeles County 0 1* 20 0 0 0 0 0 1 0 0 0 0 0 0 0 0* 0 0 0* 0 0 0 0 0074 West San Fernando Valley 13 12 8 3 9 13 4 3 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0075 Pomona/Walnut Valley 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0076 Southwest Coastal Los Angeles County 28 14 98 18 7 3 7 7 9 a) -- -- -- -- -- -- -- -- -- -- -- -- -- -- --080 Southeast Los Angeles County 0 0 1 0* 1 0 0 0 0 0 0 0 0 0 0 0 0 0 -- -- -- -- -- -- -- --084 South Central Los Angeles County 1 37 21 17 12 25 10 7 7 7 10 7 7 14 13 4 3 3 0 0 0 1 1 0 0 0 0085 South San Gabriel Valley 0* 0 5 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0087 Central Los Angeles 4 6 1 1 0 0 0 0 0 0 0 0 0 0* 0 0 0 0 0 0 0 0 0 0 0 0088 West San Gabriel Valley 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0090 Santa Clarita Valley 0 0 0 0 -- -- -- -- -- -- -- -- -- 0* 0 0 0 0 0 0 0 0 0 0 0 0091 Northwest Coastal Los Angeles County 6 21* 5 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0094 Southwest Coastal Los Angeles County -- ---- -- -- -- -- -- -- 3* 1 0 2 1 0 0 0 0 0 0 0 0 0 0 0 0801 South Central Los Angeles County 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 0* 0 0* --ORANGE COUNTY:3176 Central Orange County 5 3 1 0 11 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0* 0 0*3177 North Orange County 38* 7 0 0 0* 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 03186 Saddleback Valley 1 -- -- -- -- -- 0* 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0* --3195 North Coastal Orange County 15 0 0 1 0 0 0 0 0 0 0 0 0 0* 0 0 0 0 0 0 0 0 0 0 0* 03812 Saddleback Valley 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 0* 0RIVERSIDE COUNTY:4137 Coachella Valley 1** 0* 0 0 0* 0 0 0 0 0 0 0 0 0 0 0 0 0* 0* 0 0 0 0 0 0 0 04144 Metropolitan Riverside County 1 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0* 0 0 0 04146 Metropolitan Riverside County 2 0* -- -- -- -- -- -- 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0* 0 04149 Perris Valley 0* 0* 0 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4150 San Gorgonio Pass 0* 0 0 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4155 Norco/Corona 0 0* 0* 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4157 Coachella Valley ** 0* 0* 0* 0* -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 0* --SAN BERNARDINO COUNTY:5175 Northwest San Bernardino Valley 0* 0* 0 0 0 0* -- 0 0 0 0 0 0 0 0 0* -- -- -- -- -- -- -- -- -- --5181 Central San Bernardino Mountains 0* 0* 0 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --5197 Central San Bernardino Valley 1 0 0* 0 00* 0 0 0 0 0 0 0 0 0 0 0* -- -- -- -- -- -- -- -- -- --5203 Central San Bernardino Valley 2 0 0* 0 00 0 0 0 0 0* 0* 0 0 0 0 0 0 0 0 0 0 0* 0 0 0* 05204 East San Bernardino Valley 1 0 0 0 0 0 0 0 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --District Maximum 38 21 17 12 25 13 9 7 7 10 7 7 14 13 4 3 3 0 0 0 1 0 0 0 0 0a) Station relocated in 1986.* Incomplete data.** Salton Sea Air BasinTABLE A-9Carbon MonoxideAnnual Maximum 8-Hour Average, ppm1976-2001STN# LOCATION 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:060 East San Gabriel Valley10.6 10.8 8.6 9.0 8.8 9.5 6.9 6.6 4.6 4.9 5.5 6.0 6.0 5.8 5.1 5.9 4.9 4.0 4.5 6.3 4.0 4.3 3.9 3.9 4.9 2.9069 East San Fernando Valley26.3 21.9 16.8 15.4 24.8 21.1 16.4 16.6 12.0 16.1 16.4 12.5 11.9 13.9 13.0 10.6 10.5 8.4 10.7 12.0 9.3 7.4 7.5 9.0 6.1 4.9072 South Coastal Los Angeles County14.6 17.3 16.8 12.1 12.9 11.3 11.6 12.1 10.3 15.7 10.3 9.4 10.3 10.1 9.1 9.3 8.1 6.9 8.9 6.6 6.9 6.7 6.6 5.4 5.8 4.7074 West San Fernando Valley20.9 20.5 24.3 19.5 19.5 21.6 19.4 16.0 11.0 14.1 15.7 12.1 13.1 12.5 14.9 13.5 9.9 9.0 10.8 10.3 8.5 9.8 9.3 7.6 9.8 6.0075 Pomona/Walnut Valley11.7 12.6 12.0 9.6 10.8 9.6 9.1 8.0 7.3 7.4 8.7 10.0 8.6 7.4 7.5 7.1 8.3 5.5 6.8 6.1 5.0 5.0 7.3 6.7 4.9 3.4076 Southwest Coastal Los Angeles County25.3 20.4 24.3 21.4 21.6 19.2 19.2 18.4 19.7 24.0 a) -- -- -- -- ---- -- -- -- -- -- -- ----080 Southeast Los Angeles County14.4 13.6 15.5 14.1 15.8 13.7 12.7 13.6 9.4 14.6 8.7 9.7 7.3 8.8 9.0 7.59.37 5.86 7.7 -- -- -- -- ----084 South Central Los Angeles County 123.3 27.4 21.1 23.4 25.8 25.3 21.3 20.9 18.9 27.7 19.7 19.6 27.5 21.8 16.8 17.418.75 14.63 18.10 13.86 17.3 17.0 13.4 11.0 10.07.7085 South San Gabriel Valley14.9 14.8 18.3 12.1 14.5 11.9 11.9 10.9 8.7 13.1 10.7 10.0 9.9 10.7 9.4 9.18.62 6.43 9.29 7.86 8.1 6.2 6.1 5.6 5.34.0087 Central Los Angeles17.0 21.3 15.4 15.7 14.0 14.9 11.9 13.1 9.1 9.9 11.6 10.9 11.4 9.8 9.9 9.09.50 6.75 8.43 8.37 8.4 7.9 6.1 6.3 6.04.6088 West San Gabriel Valley12.4 16.6 13.3 12.5 13.6 11.8 12.9 12.3 8.0 11.3 10.1 11.3 10.6 8.4 10.0 9.57.25 6.25 8.50 9.12 7.1 6.0 6.3 6.6 7.45.0090 Santa Clarita Valley6.8 10.8 5.8 6.4 4.5 -- -- -- -- -- -- -- -- 5.4 4.6 5.13.71 3.86 3.86 4.12 3.9 6.8 3.4 3.6 4.93.1091 Northwest Coastal Los Angeles County17.3 16.1 15.5 19.3 16.3 14.8 14.6 12.9 11.6 10.7 8.6 7.5 8.6 8.0 8.0 6.15.87 5.43 6.00 5.62 4.5 4.4 4.5 3.8 4.33.0094 Southwest Coastal Los Angeles County-- -- -- -- -- -- -- -- -- -- 15.0 14.1 15.9 16.4 12.7 11.312.29 10.71 12.00 8.86 11.6 10.3 9.4 8.4 7.05.1801 South Central Los Angeles County 2-- -- -- -- -- -- -- -- -- -- -- ---- -- -- -- -- -- -- -- -- -- 13.5 11.7 9.5--ORANGE COUNTY:3176 Central Orange County24.8 15.9 15.5 13.8 21.3 13.4 9.6 10.9 14.4 17.0 9.7 8.7 12.0 12.1 11.7 8.69.37 7.71 8.62 8.00 7.5 5.8 5.3 5.3 6.84.73177 North Orange County24.0 21.6 13.5 13.0 13.8 13.0 11.9 11.7 9.6 14.0 10.3 10.6 9.9 10.7 9.6 8.09.14 6.00 8.75 6.62 6.9 6.0 6.1 5.3 6.14.73186 Saddleback Valley 1-- -- -- -- -- 7.0 5.3 5.7 6.1 7.7 4.9 6.3 5.1 5.1 5.6 4.87.25 4.13 5.37 4.00 4.0 3.6 3.1 2.5 2.3--3195 North Coastal Orange County20.6 12.4 12.8 15.9 13.9 11.7 10.4 10.6 9.6 13.3 10.4 8.4 11.6 12.7 10.7 8.19.14 7.33 7.86 6.57 7.3 5.8 7.0 6.4 6.34.63812 Saddleback Valley 2-- -- -- -- -- -- -- -- -- -- -- ---- -- -- -- -- -- -- -- -- -- -- -- 3.32.4RIVERSIDE COUNTY:4137 Coachella Valley 1**3.1 3.5 3.1 3.0 3.6 3.8 2.6 2.8 2.1 2.6 3.6 2.9 2.1 2.9 2.3 2.52.4 2.00 1.87 1.50 1.6 1.4 1.6 1.8 1.61.54144 Metropolitan Riverside County 18.6 9.5 7.6 8.1 7.4 7.5 6.4 6.3 6.3 5.7 6.0 6.1 6.8 10.3 6.3 7.45.25 7.13 5.75 5.71 5.0 5.8 4.6 4.4 4.33.44146 Metropolitan Riverside County 29.5 -- -- -- -- -- -- 7.9 8.9 9.1 8.3 7.6 10.0 8.5 7.3 6.96.12 6.25 7.25 6.50 5.4 5.0 4.6 4.1 4.34.54149 Perris Valley7.6 6.5 5.1 5.0 4.8 -- -- -- -- -- -- -- -- -- -- ---- -- -- -- -- -- -- -- ----4150 San Gorgonio Pass4.6 4.8 3.1 5.0 2.1 -- -- -- -- -- -- -- -- -- -- ---- -- -- -- -- -- -- -- ----4155 Norco/Corona8.0 11.1 7.5 6.6 9.3 -- -- -- -- -- -- -- -- -- -- ---- -- -- -- -- -- -- -- ----4157 Coachella Valley 2**7.1 6.0 6.5 4.8 -- -- -- -- -- -- -- -- -- -- -- ---- -- -- -- -- -- -- -- 2.1--4158 Lake Elsinore-- -- -- -- -- -- -- -- -- -- -- ---- -- -- -- -- -- -- -- -- -- -- -- 2.02.0SAN BERNARDINO COUNTY:5175 Northwest San Bernardino Valley6.8 5.4 6.4 6.3 9.0 6.6 1.9 12.5 5.6 6.3 6.6 5.1 5.0 5.4 6.6 4.6 -- -- -- -- -- -- -- -- 2.6 1.85181 Central San Bernardino Mountains5.6 5.9 6.8 6.3 4.1 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --5197 Central San Bernardino Valley 17.3 8.4 9.8 9.8 8.5 7.6 4.4 5.1 4.4 4.0 5.9 4.0 5.6 5.8 4.9 4.4 -- -- -- -- -- -- -- -- -- --5203 Central San Bernardino Valley 29.3 12.1 8.5 7.6 8.1 6.0 6.9 5.4 5.1 5.3 6.7 6.7 7.6 8.1 6.0 7.0 5.9 6.0 6.5 6.3 4.6 6.0 4.6 4.0 4.3 3.35204 East San Bernardino Valley 19.1 8.4 6.4 6.8 4.4 4.9 3.0 3.0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --District Maximum 26.3 27.4 24.3 23.4 25.8 25.3 21.3 20.9 19.7 27.7 19.7 19.6 27.5 21.8 16.8 17.4 18.8 14.6 18.1 13.9 17.3 17.013.5 11.7 10.0 7.7a) Station relocated in 1986.** Salton Sea Air BasinTABLE A-10Suspended Particulates (PM10)Annual Arithmetic Mean, μg/m31985-2001STN# LOCATION 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:060 East San Gabriel Valley 1 67 61 68 63 61 55 66 47 43 44 49 45 46 41 56 46 45069 East San Fernando Valley 70 63 60 62 65 52 55 49 45 38 42 42 45 36 44 39 41072 South Coast Los Angeles County 55 56 50 52 51 44 40 39 37 40 39 35 41 32 39 38 37087 Central Los Angeles 70 59 57 58 61 53 57 48 47 45 43 41 43 37 45 40 44090 Santa Clarita Valley -- -- -- -- 54 43 47 35 33 36 37 33 33 30 38 33 32094 Southwest Coastal Los Angeles County -- -- -- -- 50 41 39 33 37 36 36 33 36 33 36 36 37108 Pomona/Walnut Valley -- -- -- -- -- -- -- -- -- -- -- 37 40 -- -- -- --ORANGE COUNTY:3176 Central Orange County 1 -- -- -- -- -- 49 45 40 38 37 44 35 39 36 49 40 363186 Saddleback Valley 1 47 37 40 38 42 43 37 34 34 33 38 30 35 31 37 29 --3190 Central Orange County 56 48 49 46 46 -- -- -- -- -- -- -- -- -- -- -- --3812 Saddleback Valley 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- 29 28 26RIVERSIDE COUNTY:4137 Coachella Valley 1** -- -- 33 29 45 35 43 30 27 28 27 29 26 26 29 24 274144 Metropolitan Riverside County 1 96 86 90 95 94 78 76 63 72 66 69 61 65 56 72 60 634149 Perris Valley -- -- 49 59 61 59 49 45 50 45 47 40 45 38 50 41 414150 San Gorgonio Pass 51 41 44 42 47 35 38 34 33 35 30 34 38 28 -- -- --4155 Norco/Corona 45 -- -- -- -- -- -- -- 53 53 54 44 50 47 55 49 --4157 Coachella Valley 2** 68 50 51 48 90 79 69 43 46 49 52 51 49 48 53 52 504163 Temecula Valley -- -- -- -- -- -- 38 31 27 22 -- -- -- -- -- -- --4164 Banning Airport -- -- -- -- -- -- -- -- -- -- -- -- -- 27 35 29 35SAN BERNARDINO COUNTY:5171 Southwest San Bernardino Valley 1 74 76 70 78 79 72 68 79 58 50 54 51 51 47 55 -- --5181 Central San Bernardino Mountains -- -- -- -- 39 37 39 33 31 26 20 24 24 25 27 24 --5197 Central San Bernardino Valley 1 74 76 74 81 77 78 63 56 57 60 61 55 54 50 60 53 515203 Central San Bernardino Valley 2 -- 85 70 80 81 65 61 57 56 54 57 53 51 46 57 50 525204 East San Bernardino Valley -- -- -- -- -- -- -- -- 45 47 48 46 43 41 47 46 475817 Southwest San Bernardino Valley 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- 66 50 52District Maximum96 86 90 95 94 79 76 79 72 66 69 61 65 56 72 60 63** Salton Sea Air BasinTABLE A-11Suspended Particulates (PM10)Annual Geometric Mean, μg/m31985-2001STN# LOCATION 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:060 East San Gabriel Valley 1 59 54 59 56 54 48 60 40 36 38 41 39 41 36 52 43 40069 East San Fernando Valley 65 57 54 57 60 48 49 42 39 34 37 42 42 33 41 36 37072 South Coast Los Angeles County 52 51 46 47 46 41 37 37 34 37 32 31 38 29 36 33 35087 Central Los Angeles 66 54 51 53 56 48 51 44 43 41 36 37 39 34 42 37 40090 Santa Clarita Valley -- -- -- -- 49 39 43 31 28 32 31 30 31 27 35 30 29094 Southwest Coastal Los Angeles County -- -- -- -- 45 38 35 30 33 33 31 29 34 30 33 33 34108 Pomona/Walnut Valley -- -- -- -- -- -- -- -- -- -- -- 33 38 -- -- -- --ORANGE COUNTY:3176 Central Orange County 1 -- -- -- -- -- 43 40 37 34 34 36 32 36 33 43 36 343186 Saddleback Valley 1 43 34 36 35 38 40 34 32 30 30 32 27 33 28 34 27 --3190 Central Orange County 2 52 44 42 40 42 -- -- -- -- -- -- -- -- -- -- -- --3812 Saddleback Valley 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- 28 26 24RIVERSIDE COUNTY:4137 Coachella Valley 1** -- -- 24 24 36 30 37 24 24 24 24 25 24 24 26 23 244144 Metropolitan Riverside County 1 81 74 73 81 81 67 65 52 58 56 52 52 56 49 65 55 544149 Perris Valley -- -- 32 52 52 50 43 38 41 39 37 35 39 33 44 37 364150 San Gorgonio Pass 40 33 34 34 37 29 31 29 26 27 25 27 30 24 -- -- --4155 Norco/Corona -- -- -- -- -- -- -- -- 44 45 45 40 44 41 49 43 394157 Coachella Valley 2** 55 46 44 43 66 65 61 39 41 45 47 46 44 44 50 48 444163 Temecula Valley -- -- -- -- -- -- 36 28 24 19 -- -- -- -- -- -- --4164 Banning Airport -- -- -- -- -- -- -- -- -- -- -- -- -- 24 30 25 27SAN BERNARDINO COUNTY:5171 Southwest San Bernardino Valley 1 65 65 60 67 70 61 60 62 37 45 44 46 45 40 50 -- --5181 Central San Bernardino Mountains -- -- -- -- 36 31 35 30 25 22 18 20 21 21 24 21 --5197 Central San Bernardino Valley 1 63 63 58 67 68 63 58 49 46 53 51 48 48 43 54 47 445203 Central San Bernardino Valley 2 -- 74 55 67 69 55 52 49 48 46 48 46 46 39 51 45 455204 East San Bernardino Valley -- -- -- -- -- -- -- -- 35 38 37 38 35 34 41 40 405817 Southwest San Bernardino Valley 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- 59 46 46District Maximum81 74 73 81 81 67 65 62 58 56 52 52 56 49 65 55 54** Salton Sea Air BasinTABLE A-12Suspended Particulates (PM10) - Percent of Sampling DaysExceeding State Standard (50 μg/m3)And Federal Standard (150 μg/m3),1985-2001STN# LOCATION 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:060 East San Gabriel Valley 1 68/0 61/4 64/3 67/0 59/2 50/0 68/0 39/0 32/0 40/0 40/2 41/0 40/0 28/0 58/0 42/0 38/0069 East San Fernando Valley 77/2 67/3 61/0 68/0 69/0 47/2 50/0 31/3 36/018/0 25/0 25/0 30/0 15/0 35/0 23/0 23/0072 South Coast Los Angeles County 58/0 40/0 33/0 40/044/0 24/0 24/0 19/0 20/0 18/0 19/0 15/0 18/0 10/0 22/0 21/0 17/0087 Central Los Angeles 85/0 66/2 62/2 57/0 57/052/2 54/2 36/0 43/0 33/0 23/018/0 25/0 17/0 33/0 25/0 33/0090 Santa Clarita Valley -- -- -- -- 44/0 28/0 23/0 9/0 15/0 18/0 14/0 9/0 9/0 6/0 21/0 7/0 7/0094 Southwest Coastal Los Angeles County -- -- -- --48/0 26/0 42/0 13/0 15/0 22/0 21/0 8/0 7/0 12/0 10/0 16/0 14/0108 Pomona/Walnut Valley -- -- -- -- -- -- -- -- -- -- -- 18/0 18/0 -- -- -- --ORANGE COUNTY:3176 Central Orange County 1 -- -- -- -- -- 34/224/0 20/0 21/0 18/0 23/2 10/0 18/0 20/0 39/0 13/0 20/03186 Saddleback Valley 1 37/0 8/0 25/0 18/0 33/0 29/0 15/0 8/0 12/0 12/0 18/0 7/0 7/0 10/0 10/0 3/0 --3190 Central Orange County 2 57/0 33/0 36/2 26/0 38/0 -- -- -- -- -- -- -- -- -- -- -- --3812 Saddleback Valley 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- 3/0 3/0 5/0RIVERSIDE COUNTY:4137 Coachella Valley 1** -- -- -- 13/0 28/3 15/0 25/2 7/2 2/0 3/0 4/0 3/0 2/0 5/0 5/0 0/0 2/04144 Metropolitan Riverside County 1 75/18 79/8 77/12 84/12 84/12 75/5 68/3 64/0 69/7 67/2 62/768/2 70/2 54/0 72/2 70/0 67/04149 Perris Valley -- -- 33/0 63/2 66/2 53/5 43/041/0 45/0 43/0 38/0 33/0 32/0 26/0 50/0 22/0 27/04150 San Gorgonio Pass 50/0 33/0 36/2 30/0 33/320/0 30/0 17/0 18/0 23/0 12/0 19/0 25/0 9/0 -- -- --4155 Norco/Corona -- -- -- -- -- -- -- --51/2 58/0 47/3 33/0 42/2 40/0 55/0 48/0 33/04157 Coachella Valley 2** 67/5 45/0 41/0 36/0 67/7 70/7 63/5 31/0 41/0 38/0 44/2 50/0 43/0 40/0 54/0 50/0 45/04163 Temecula Valley -- -- -- -- -- -- 21/0 4/0 3/0 0/0 -- -- -- -- -- -- --4164 Banning Airport -- -- -- -- -- -- -- -- -- -- -- -- -- 4/0 12/0 8/0 13/2SAN BERNARDINO COUNTY:5171 Southwest San Bernardino Valley 1 70/2 74/9 68/2 78/3 80/7 63/7 67/2 66/3 62/0 44/0 51/5 53/0 36/2 34/0 56/0 -- --5181 Central San Bernardino Mountains -- -- -- -- 22/019/0 13/0 8/0 4/0 5/0 2/0 0/0 0/0 0/0 0/0 0/0 --5197 Central San Bernardino Valley 160/7 68/7 63/5 77/7 77/3 73/5 65/0 59/0 57/0 63/0 57/3 57/0 48/0 47/0 61/0 52/0 57/05203 Central San Bernardino Valley2 -- 76/5 59/3 71/5 75/5 58/3 68/2 60/0 63/0 51/0 53/0 58/0 45/0 38/0 56/0 53/0 52/05204 East San Bernardino Valley -- -- -- -- ---- -- -- 46/0 41/0 41/2 42/0 38/0 32/0 40/0 44/0 45/05817 Southwest San Bernardino Valley 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- 67/2 45/0 42/2** Salton Sea Air BasinTABLE A-13Suspended Particulates (PM10)Annual Maximum 24-Hour Average, μg/m31985-2001STN# LOCATION 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:060 East San Gabriel Valley 1 149 183 188 127 172 127 137 107 101 127 157 100 116 87 103 94 106069 East San Fernando Valley 165 211 147 138 133 161 133 222 93 114 135 110 92 75 82 74 86072 South Coast Los Angeles County 106 136 113 149 119 119 92 67 86 97 146 113 87 69 79 105 91087 Central Los Angeles 146 178 158 130 137 152 151 137 104 122 141 138 102 80 88 80 97090 Santa Clarita Valley -- -- -- -- 100 93 81 84 75 66 87 91 67 60 75 64 62094 Southwest Coastal Los Angeles County -- -- -- -- 133 127 79 67 91 81 136 107 79 66 69 74 75108 Pomona/Walnut Valley -- -- -- -- -- -- -- -- -- -- -- 103 67 -- -- -- --ORANGE COUNTY:3176 Central Orange County 1 -- -- -- -- -- 158 146 88 92 106 172 101 91 81 122 126 933186 Saddleback Valley 1 100 109 107 97 88 88 94 83 115 91 122 79 86 70 111 60 --3190 Central Orange County 2 144 124 163 132 138 -- -- -- -- -- -- -- -- -- -- -- --3812 Saddleback Valley 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- 56 98 60RIVERSIDE COUNTY:4137 Coachella Valley 1** -- -- 121 77 292 83 197 175 58 55 68 130 63 72 104 44 534144 Metropolitan Riverside County 1 208 294 219 252 252 207 179 126 231 161 219 162 163 116 153 139 1364149 Perris Valley -- -- 187 164 187 250 113 115 131 112 145 87 139 98 112 87 864150 San Gorgonio Pass 135 135 163 113 194 89 87 89 87 96 138 122 227 76 -- -- --4155 Norco/Corona -- -- -- -- -- -- -- -- 164 139 177 94 158 93 136 129 1094157 Coachella Valley 2** 358 111 115 115 712 520 340 117 125 97 199 117 144 114 119 114 1494163 Temecula Valley -- -- -- -- -- -- 66 88 105 48 -- -- -- -- -- -- --4164 Banning Airport -- -- -- -- -- -- -- -- -- -- -- -- -- 62 86 69 219SAN BERNARDINO COUNTY:5171 Southwest San Bernardino Valley 1 157 272 182 192 254 185 158 649 138 138 167 129 208 92 112 -- --5181 Central San Bernardino Mountains -- -- -- -- 87 88 105 62 73 67 53 45 47 45 47 49 --5197 Central San Bernardino Valley 1 154 275 203 287 227 475 127 105 143 133 178 130 122 101 116 108 1065203 Central San Bernardino Valley 2 -- 285 211 289 271 235 163 136 139 147 148 136 108 114 134 108 1065204 East San Bernardino Valley -- -- -- -- -- -- -- -- 109 138 172 128 103 97 92 109 1025817 Southwest San Bernardino Valley 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 124 166District Maximum358 294 219 289 712 520 340 649 231 161 219 162 227 116 153 139 219** Salton Sea Air BasinTABLE A-14Nitrogen Dioxide - Annual Average of All Hours, pphm, 1976-2001a)(To Be Compared to Federal Standard of5.34 pphm, Annual Average of All Hours)STN# LOCATION 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 19971998 1999 2000 2001LOS ANGELES COUNTY:060 East San Gabriel Valley 1 4.71 5.77 5.29 3.64 3.71 5.03 4.94 4.70 4.35 5.02 4.96 4.98 5.30 5.11 4.10 4.50 4.03 4.00 4.304.64 4.15 3.38 3.64 3.90 3.66 3.31069 East San Fernando Valley 6.31 6.58 7.18 6.86 7.06 7.13 6.15 5.57 5.60 5.71 5.74 5.16 5.28 5.07 4.79 4.68 5.01 4.40 4.974.54 4.61 4.24 4.16 4.56 4.15 4.19072 South Coastal Los Angeles County 6.50 6.34 5.81 6.04 4.87 5.38 5.12 4.56 4.98 4.99 5.29 4.32 4.75 4.28 3.93 4.11 3.89 3.57 3.46 3.67 3.42 3.33 3.39 3.42 3.13 3.08074 West San Fernando Valley 4.88 5.19 4.59 5.29 4.99 4.90 4.50 4.41 3.89 3.85 2.77 3.19 3.78 3.90 3.40 3.99 3.17 3.06 3.393.17 3.07 2.60 2.66 2.87 2.85 2.66075 Pomona/Walnut Valley 1 5.98 6.30 6.20 5.18 5.03 5.06 5.50 5.20 5.16 5.41 5.58 5.47 5.61 5.71 5.55 5.50 5.07 4.99 4.80 4.56 4.26 4.33 4.33 5.03 4.35 3.71076 Southwest Coastal Los Angeles County 6.36 6.08 5.49 5.75 5.79 5.90 5.27 4.44 4.61 4.32 c) -- -- -- -- -- -- -- -- -- ---- -- -- -- --080 Southeast Los Angeles County 6.36 6.49 6.13 6.04 5.10 5.48 5.35 5.16 4.48 4.79 5.04 4.86 4.98 4.44 4.28 3.94 3.76 3.76 -- -- -- -- -- -- -- --084 South Central Los Angeles County 1 4.67 5.70 4.68 5.39 5.00 5.74 4.96 4.62 5.45 5.23 5.28 4.29 4.78 4.59 4.08 4.37 4.554.09 4.99 4.63 4.12 4.28 3.93 4.28 3.86 3.69085 South San Gabriel Valley 7.22 7.49 6.61 6.33 5.87 6.06 5.79 5.04 4.88 5.32 5.29 4.89 5.39 5.47 4.99 4.69 4.43 4.28 4.494.56 3.93 3.63 3.69 3.91 3.66 3.52087 Central Los Angeles 6.40 7.73 6.64 5.82 6.10 6.68 6.02 5.88 5.67 5.99 6.12 5.37 6.13 5.53 4.67 4.93 4.04 3.32 4.76 4.504.36 4.30 3.98 3.91 4.04 3.78088 West San Gabriel Valley 6.84 7.80 7.34 6.03 5.53 5.78 5.55 4.84 4.85 5.01 5.13 4.20 5.00 5.31 4.74 5.02 4.23 3.90 4.28 3.75 3.78 3.41 3.51 3.79 2.96 3.45090 Santa Clarita Valley 2.39 3.10 3.18 2.18 -- -- -- -- -- -- -- -- -- -- 3.16 3.24 2.76 2.89 3.27 3.05 -- -- -- 2.84 2.462.39091 Northwest Coastal Los Angeles County 6.68 7.00 5.59 6.42 5.75 5.37 5.22 4.98 4.36 3.84 4.21 3.78 3.43 3.15 3.24 2.78 2.84 2.87 2.96 2.78 2.89 2.85 2.71 2.91 2.73 2.51094 Southwest Coastal Los Angeles County -- -- -- -- -- -- -- -- -- -- 4.20 3.53 3.58 3.74 3.39 2.98 3.20 3.00 3.22 3.05 2.85 2.80 2.95 2.95 2.75 2.50108 Pomona/Walnut Valley 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 4.58 4.53 3.82 -- -- -- -- --591 East San Gabriel Valley 2 -- -- -- -- -- -- -- -- -- -- -- 3.77 4.39 3.89 3.77 4.30 3.53 3.39 3.62 3.80 3.28 3.00 2.76 3.28 2.90 2.74801 South Central Los Angeles County 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 4.04 2.92 --ORANGE COUNTY:3176 Central Orange County 4.81 5.04 4.33 4.82 5.20 4.97 4.64 4.46 4.41 4.30 4.46 4.21 4.58 4.72 4.69 4.48 3.94 3.54 3.80 3.71 3.19 3.32 3.36 3.27 3.003177 North Orange County 4.32 5.43 5.31 5.30 5.13 5.26 4.78 4.55 4.63 4.26 4.21 3.82 4.24 4.28 4.47 4.26 3.79 3.87 4.14 3.913.54 3.29 3.44 3.51 3.043195 North Coastal Orange County 2.39 2.47 2.52 2.70 2.50 3.24 3.11 2.80 2.58 2.48 2.60 2.81 2.68 4.63 2.72 2.60 2.49 2.20 2.44 2.39 2.06 1.99 2.00 2.09 2.05RIVERSIDE COUNTY:4137 Coachella Valley 1** -- -- -- 1.84 1.89 1.87 2.45 2.73 1.43 1.96 1.86 1.90 2.20 2.39 2.06 2.08 2.10 1.95 2.19 2.23 2.101.58 1.70 1.95 1.78 1.754144 Metropolitan Riverside County 3.17 4.19 3.13 3.25 3.42 3.63 3.36 3.44 3.54 3.53 3.16 2.69 3.68 3.64 3.36 3.51 3.04 2.983.20 3.06 2.94 2.62 2.25 2.25 2.36 2.474149 Perris Valley -- -- -- -- -- -- -- -- -- -- -- -- 3.10 3.22 2.82 -- -- -- -- -- -- -- -- -- -- --4157 Coachella Valley 2** 1.99 1.75 1.52 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 0.99 --4158 Lake Elsinore -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 2.12 2.08 1.82 1.65 1.74 2.00 1.75 1.854164 Banning Airport -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 2.15 2.43 2.37 2.11SAN BERNARDINO COUNTY:5175 Northwest San Bernardino Valley 4.07 6.10 4.42 6.11 4.88 4.90 -- 4.20 4.05 3.98 4.23 4.72 4.72 4.48 4.11 4.28 3.96 4.214.15 4.64 3.87 3.41 3.59 3.98 3.80 3.845197 Central San Bernardino Valley 1 3.53 3.40 4.25 3.39 3.90 4.24 3.68 3.36 3.78 3.73 4.18 3.83 3.69 3.63 3.43 3.77 3.44 3.72 4.03 4.24 3.86 3.65 3.62 3.88 3.64 3.585203 Central San Bernardino Valley 2 2.15 2.67 2.57 3.16 4.79 4.86 4.33 3.60 4.00 3.79 4.37 4.30 4.21 4.09 3.93 3.55 3.56 3.76 4.11 4.04 3.84 3.53 3.39 3.58 3.25 3.035204 East San Bernardino Valley 2.17 2.78 2.45 1.83 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --District Maximum7.22 7.80 7.34 6.86 7.06 7.13 6.15 5.88 5.67 5.99 6.12 5.47 6.13 5.71 5.55 5.50 5.07 4.99 4.99 4.64 4.61 4.33 4.33 5.03 4.35 4.19a) Data prior to 1980 have been multiplied by an adjustment factor of 0.877 tobe made comparable to 1980-2001 data.b) 1982 annual averages are based on the arithmetic mean of the monthly averages and may differ slightly from the annual average of all hours.c) Station relocated in 1986.**Salton Sea Air Basin.TABLE A-15Nitrogen Dioxide - Number of Days 1-Hour AverageExceeded the State Standard (> .25 ppm), 1976-2001STN# LOCATION 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:060 East San Gabriel Valley 11 7 8 1 1 3 3 1 0 1 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0069 East San Fernando Valley4 12 26 11 22 9 1 4 0 1 1 1 2 0 0 2 0 0 0 0 0 0 0 0 0 0072 South Coastal Los Angeles County25 14 4 7 4 10 3 3 5 3 1 1 1 1 1 2 0 0 0 0 0 0 0 0 0 0074 West San Fernando Valley1 5 5 3 2 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0075 Pomona/Walnut Valley 15 7 4 2 1 4 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0076 Southwest Coastal Los Angeles County6 16 6 6 2 8 3 3 1 0 a) -- -- -- -- -- -- -- -- -- -- -- -- -- -- --080 Southeast Los Angeles County7 13 8 6 4 10 4 4 2 3 1 0 0 1 0 0 0 0 -- -- -- -- -- -- -- --084 South Central Los Angeles County 13 4 0 4 1 5 0 1 2 1 1 1 1 2 1 2 0 0 0 0 0 0 0 0 0 0085 South San Gabriel Valley10 33 14 7 6 8 2 4 0 4 1 0 0 3 2 0 1 1 0 0 0 0 0 0 0 0087 Central Los Angeles16 42 15 8 15 16 8 4 0 2 6 4 6 1 3 5 1 0 0 0 0 0 0 0 0 0088 West San Gabriel Valley12 26 15 7 11 2 1 3 0 1 0 0 2 2 0 2 0 0 0 0 0 0 0 0 0 0090 Santa Clarita Valley0 0 0 1 0 -- -- -- -- -- -- -- -- 0 0 0 0 0 0 0 -- -- -- 0 0 0091 Northwest Coastal Los Angeles County37 30 11 25 16 6 4 4 3 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0094 Southwest Coastal Los Angeles County-- -- -- -- -- -- -- -- -- -- 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0108 Pomona/Walnut Valley 2-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 0 0 0 -- -- -- -- --591 East San Gabriel Valley 2-- -- -- -- -- -- -- -- -- -- 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0801 South Central Los Angeles County 2-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 0 0 --ORANGE COUNTY:3176 Central Orange County7 2 1 1 15 3 0 0 0 2 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 03177 North Orange County0 1 3 0 5 7 1 3 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 03195 North Coastal Orange County4 0 2 1 2 2 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0RIVERSIDE COUNTY:4137 Coachella Valley 1**-- -- -- 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 04144 Metropolitan Riverside County0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 04149 Perris Valley-- -- -- -- -- -- -- -- -- -- -- -- 0 0 0 -- -- -- -- -- -- -- -- -- -- --4157 Coachella Valley 2**0 0 0 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 0 --4158 Lake Elsinore -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --0 0 0 0 0 0 0 04164 Banning Airport-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 1 1 0 0SAN BERNARDINO COUNTY:5175 Northwest San Bernardino Valley0 2 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 05197 Central San Bernardino Valley 11 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 05203 Central San Bernardino Valley 20 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 05204 East San Bernardino Valley0 0 0 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- - -- -- -- -- -- --a) Station relocated in 1986.** Salton Sea Air BasinTABLE A-16Nitrogen DioxideAnnual Maximum 1-Hour, ppma)1976-2001STN# LOCATION 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:060 East San Gabriel Valley 1 .27 .35 .38 .35 .27 .28 .30 .26 .16 .27 .21 .23 .24 .27 .21 .25 .15 .17 .19 .22 .15 .16 .14 .16 .15 .12069 East San Fernando Valley .33 .40 .44 .31 .35 .37 .26 .30.21 .31 .28 .26 .26 .25 .23 .29 .19 .17 .18 .18 .20 .20 .14 .18.17 .25072 South Coastal Los Angeles County .38.38 .35 .41 .31 .37 .30 .37 .35 .35 .26 .26 .28 .27 .27 .28 .18 .20 .20 .21 .17 .20.16 .15 .14 .13074 West San Fernando Valley .26 .35 .46 .27 .32 .24 .24 .23.21 .21 .22 .15 .20 .18 .19 .17 .17 .15 .17 .14 .16 .20 .14 .12.11 .09075 Pomona/Walnut Valley 1 .28 .31 .32 .30 .27 .31 .32 .21 .20 .23 .25 .22 .20 .26 .21 .22 .18 .20 .17 .18 .18 .15 .15 .16 .14 .13076 Southwest Coastal Los Angeles County .34 .38 .34 .33 .38 .42 .34 .32 .27 .24 b) -- -- -- -- -- -- -- -- -- -- -- -- -- -- --080 Southeast Los Angeles County .46 .61 .44 .32 .47 .38 .30 .32 .29 .31 .28 .25 .22 .29 .23 .22 .21 .20 -- -- -- -- -- -- -- --084 South Central Los Angeles County 1 .34 .29 .23 .32 .29 .32 .24 .27 .27 .31 .26 .26 .31 .34 .26 .26 .25 .23 .20 .21 .25 .20 .16 .18 .14 .15085 South San Gabriel Valley .46 .39 .40 .36 .54 .36 .29 .31.25 .31 .26 .24 .24 .31 .27 .25 .27 .26 .24 .23 .17 .15 .14 .16.14 .14087 Central Los Angeles .46 .53 .37 .41 .44 .45 .41 .33 .23 .27 .33 .42 .54 .28 .28 .38 .30 .21 .22 .24 .25 .20 .17 .21 .16.14088 West San Gabriel Valley .33 .42 .52 .32 .35 .40 .34 .35 .21 .27 .24 .21 .27 .34 .23 .32 .22 .18 .18 .22 .19 .17 .16 .16.17 .15090 Santa Clarita Valley .11 .29 .18 .25 .10 -- -- -- -- -- -- -- -- .13 .15 .17 .11 .13 .12 .16 -- -- -- .10 .10 .10091 Northwest Coastal Los Angeles County .40 .49 .49 .40 .37.40 .39 .47 .32 .23 .24 .27 .26 .22 .20 .25 .17 .17 .16 .20 .18.14 .13 .13 .16 .11094 Southwest Coastal Los Angeles County -- -- -- -- -- -- -- ---- -- .23 .23 .27 .24 .23 .21 .19 .16 .22 .18 .15 .17 .15 .13 .13 .11108 Pomona/Walnut Valley 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 22 .21 .18 -- -- -- -- --591 East San Gabriel Valley 2 -- -- -- -- -- -- -- -- -- -- .13 .17 .20 .22 .19 .23 .16 .16 .19 .20 .14 .13 .13 .14 .13 .12801 South Central Los Angeles County 2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- .16 .11 --ORANGE COUNTY:3176 Central Orange County .40 .25 .26 .29 .43 .30 .20 .24 .24 .28 .21 .22 .28 .28 .21 .20 .21 .20 .19 .18 .15 .10 .13 .12 .13 .123177 North Orange County .25 .34 .33 .21 .42 .36 .28 .33 .25 .30 .20 .22 .24 .23 .22 .20 .17 .18 .23 .20 .16. .15 .13 .16 .12.133195 North Coastal Orange County .30 .20 .26 .25 .31 .29 .23 .27 .22 .24 .20 .19 .26 .22 .22 .16 .15 .14 .16 .18 .14 .12 .12.12 .11 .08RIVERSIDE COUNTY:4137 Coachella Valley 1** -- -- -- .09 .13 .09 .15 .16 .09 .08 .08 .08 .11 .09 .09 .09 .09 .15 .08 .09 .08 .07 .07 .07 .07 .084144 Metropolitan Riverside County .20 .24.19 .18 .20 .32 .16 .19 .17 .16 .16 .21 .19 .16 .16 .16 .23 .14 .18 .15 .11 .12 .10 .13 .10 .154149 Perris Valley -- -- -- -- -- -- -- -- -- -- -- -- .14 .14 .11 -- -- -- -- -- -- -- -- -- -- --4157 Coachella Valley 2** .08 .13 .11 .08 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- .06 --4158 Lake Elsinore -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- .11 .21 .10 .11 .09 .11 .08 .094164 Banning Airport -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- .26 .31 .21 .24SAN BERNARDINO COUNTY:5175 Northwest San Bernardino Valley .11 .26 .24 .26 .35 .19 .20 .25 .15 .18 .24 .20 .21 .20 .19 .21 .14 .16 .17 .20 .15 .15.14 .13 .15 .135197 Central San Bernardino Valley 1 .26 .20 .26 .16 .25 .19 .18 .16 .16 .14 .18 .18 .21 .18 .20 .19 .14 .16 .18 .17 .17 .14.15 .15 .12 .135203 Central San Bernardino Valley 2 .11 .17 .12 .20 .25 .20 .19 .19 .20 .15 .18 .19 .19 .18 .20 .16 .13 .15 .16 .16 .15 .14.11 .14 .10 .115204 East San Bernardino Valley .22 .21 .18 .17 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --District Maximum.46 .61 .52 .41 .54 .45 .41 .47 .35 .35 .33 .42 .54 .34 .28 .38 .30 .26 .22 .24 .25 .20 .26 .31 .21 .25a) Data prior to 1980 have been multiplied by an adjustment factor of 0.877to be made comparable to 1980-2001 data.b) Station relocated in 1986.** Salton Sea Air BasinTABLE A-17Sulfur Dioxide - Annual Average, pphm1976-2001STN# LOCATION 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:060 East San Gabriel Valley 11.02 1.03 0.75 0.71 0.62 0.32 0.31 0.21 0.23 0.29 0.30 0.24 0.22 0.17 0.11 -- -- -- -- -- -- -- -- -- -- --069 East San Fernando Valley0.81 1.37 1.07 1.04 0.67 0.52 0.58 0.47 0.52 0.51 0.34 0.30 0.22 0.20 0.18 0.09 0.10 0.12 0.07 0.01 0.04 0.03 0.02 0.01 0.01 0.07072 South Coastal Los Angeles County1.51 1.45 1.33 0.90 1.08 0.95 1.07 0.89 0.98 0.81 0.84 0.58 0.68 0.46 0.31 0.43 0.37 0.36 0.31 0.23 0.25 0.24 0.18 0.27 0.15 0.22074 West San Fernando Valley0.77 0.95 0.47 0.33 0.48 0.44 0.45 0.43 0.41 0.25 0.33 0.26 0.17 0.18 0.15 -- -- -- -- -- -- -- -- -- -- --075 Pomona/Walnut Valley 11.02 1.41 1.16 0.60 0.41 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --076 Southwest Coastal Los Angeles County1.70 1.78 0.64 0.81 1.14 1.05 1.06 0.95 1.04 0.74 a) -- -- -- -- -- -- -- -- -- -- -- -- -- -- --080 Southeast Los Angeles County1.88 1.73 1.30 2.33 0.99 0.70 0.80 0.58 0.60 0.43 0.43 0.42 0.55 0.36 0.16 0.16 0.08 0.07 -- -- -- -- -- -- -- --084 South Central Los Angeles County 11.22 1.04 0.84 0.64 0.82 0.91 0.70 0.66 0.84 0.70 0.51 0.59 0.69 0.42 0.33 0.30 0.31 0.23 0.26 0.30 -- -- -- -- -- --085 South San Gabriel Valley0.77 0.80 0.63 0.76 0.55 0.55 0.54 0.56 0.70 0.50 0.34 0.36 0.48 0.45 0.43 -- -- -- -- -- -- -- -- -- -- --087 Central Los Angeles1.94 2.01 1.74 1.16 1.28 0.71 0.79 0.61 0.85 0.53 0.42 0.43 0.41 0.22 0.17 0.17 0.15 0.03 0.07 0.10 0.15 0.07 0.08 0.23 0.09 0.28088 West San Gabriel Valley1.52 1.53 1.48 1.05 0.61 0.38 0.47 0.35 0.33 0.25 0.19 0.28 0.23 0.22 0.15 -- -- -- -- -- -- -- -- -- -- --090 Santa Clarita Valley1.12 1.11 0.93 0.90 0.49 -- -- -- -- -- -- -- -- 0.09 0.09 -- -- -- -- -- -- -- -- -- -- --091 Northwest Coastal Los Angeles County0.79 0.87 1.12 0.88 0.66 0.40 0.28 0.23 0.27 0.32 0.33 0.28 0.22 0.24 0.21 -- -- -- -- -- -- -- -- -- -- --094 Southwest Coastal Los Angeles County-- -- -- -- -- -- -- -- -- -- 0.50 0.38 0.48 0.47 0.35 0.40 0.57 0.31 0.22 0.27 0.25 0.14 0.39 0.40 0.17 0.41ORANGE COUNTY:3176 Central Orange County 10.67 0.62 0.45 0.63 0.67 0.41 0.56 0.50 060 0.32 0.32 0.30 0.41 0.31 0.18 -- -- -- -- -- -- -- -- -- -- --3177 North Orange County0.61 0.75 0.73 0.6 0.8 0.53 0.51 0.55 0.6 0.51 0.5 0.49 0.38 0.21 0.11 0.12 0.06 0.06 0.09 0.09 -- -- -- -- -- --3186 Saddleback Valley 0.12 0.14 0.14 0.18 0.06 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --3190 Central Orange County 2 0.96 0.88 0.66 0.76 0.90 0.46 0.45 0.36 0.40 0.30 0.27 0.30 0.29 0.27 0.19 0.11 0.11 0.08 -- ---- -- -- -- -- --3195 North Coastal Orange County0.63 0.59 0.42 0.42 0.54 0.34 0.35 0.25 0.29 0.28 0.15 0.20 0.18 0.15 0.07 0.07 0.06 0.05 0.07 0.07 0.01 0.03 0.04 0.07 0.05 0.15RIVERSIDE COUNTY:4137 Coachella Valley 1**-- -- -- 0.65 0.54 0.07 0.01 0.07 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4144 Metropolitan Riverside County0.50 1.00 0.89 0.93 0.40 0.13 0.17 0.14 0.00 0.14 0.07 0.22 0.14 0.07 0.03 0.02 0.02 0.03 0.02 0.01 0.01 0.03 0.11 0.14 0.08 0.094157 Coachella Valley 2**-- 0.01 0.74 0.44 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --SAN BERNARDINO COUNTY:5175 Northwest San Bernardino Valley-- -- 0.75 0.85 0.49 0.51 0.65 0.25 0.16 0.08 0.07 0.14 0.17 0.14 0.12 -- -- -- -- -- -- -- -- -- -- --5197 Central San Bernardino Valley 12.71 2.60 0.98 0.85 0.53 0.47 0.51 0.21 0.11 0.10 0.14 0.18 0.16 0.05 0.01 0.05 0.12 0.00 0.02 0.06 0.01 0.00 0.07 0.18 0.18 0.215203 Central San Bernardino Valley 20.82 1.50 1.15 1.00 0.21 0.09 0.15 0.10 0.21 0.17 0.34 0.26 0.18 0.06 0.01 -- -- -- -- -- -- -- -- -- -- --District Maximum2.71 2.60 1.74 2.33 1.28 1.05 1.07 0.95 1.04 0.81 0.84 0.59 0.69 0.47 0.43 0.43 0.57 0.36 0.31 0.30 0.25 0.24 0.39 0.40 0.18 0.41a) Station relocated in 1986.** Salton Sea Air BasinTABLE A-18Sulfur DioxideAnnual Maximum 1-Hour Average, ppm1976-2001STN# LOCATION 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:60 East San Gabriel Valley.10 .06 .05 .06 .05 .04 .06 .03 .04 .02 .03 .03 .03 .02 .03 -- -- -- -- -- -- -- -- -- -- --69 East San Fernando Valley.09 .10 .06 .06 .04 .04 .09 .04 .05 .04 .02 .03 .02 .03 .02 .01 .03 .02 .03 .01 .01 .04 .01 .01 .01 .0172 South Coastal Los Angeles County.13 .13 .19 .13 .10 .14 .09 .12 .32 .08 .07 .06 .05 .11 .05 .14 .11 .05 .04 .14 .04 .04 .08 .05 .05 .0574 West San Fernando Valley.04 .06 .05 .03 .03 .03 .03 .03 .03 .02 .02 .02 .02 .02 .02 - -- -- -- -- -- -- -- -- -- --75 Pomona/Walnut Valley.06 .08 .06 .05 .03 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --76 Southwest Coastal Los Angeles County.18 .30 .09 .10 .08 .07 .08 .09 .06 .06 a) -- -- -- -- -- -- -- -- -- -- -- -- -- -- --80 Southeast Los Angeles County.15 .18 .10 .14 .16 .09 .09 .09 .06 .05 .06 .07 .10 .04 .04 .07 .03 .03 -- -- -- -- -- -- -- --84 South Central Los Angeles County.09 .12 .13 .09 .08 .09 .06 .06 .07 .06 .13 .06 .06 .04 .04 .05 .06 .03 .02 .03 -- -- -- -- -- --85 South San Gabriel Valley.05 .08 .05 .10 .07 .05 .05 .08 .09 .07 .03 .09 .05 .04 .04 -- -- -- -- -- -- -- -- -- -- --87 Central Los Angeles.12 .09 .09 .05 .06 .05 .05 .07 .07 .04 .03 .03 .04 .03 .02 .02 .05 .01 .02 .01 .01 .02 .14 .05 .08 .0388 West San Gabriel Valley.06 .07 .06 .06 .05 .04 .04 .05 .03 .03 .02 .02 .03 .02 .02 -- -- -- -- -- -- -- -- -- -- --90 Santa Clarita Valley.10 .04 .05 .05 .03 -- -- -- -- -- -- -- -- .02 .01 -- -- -- -- -- -- -- -- -- -- --91 Northwest Coastal Los Angeles County.07 .05 .08 .04 .04 .04 .03 .06 .05 .03 .02 .03 .03 .02 .02 -- -- -- -- -- -- -- -- -- -- --94 Southwest Coastal Los Angeles County-- -- -- -- -- -- -- -- -- -- .09 .03 .15 .09 .31 .12 .15 .07 .04 .06 .06 .10 .03 .09 .17 .04ORANGE COUNTY:3176 Central Orange County 1.11 .09 .07 .07 .08 .04 .04 .05 .08 .03 .03 .09 .06 .03 .02 -- -- -- -- -- -- -- -- -- -- --3177 North Orange County.11 .12 .10 .09 .09 .04 .04 .05 .04 .05 .06 .05 .05 .03 .03 .04 .02 .02 .02 .02 -- -- -- -- -- --3186 Saddleback Valley .05 .07 .10 .09 .06 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --3190 Central Orange County 2 .25 .14 .16 .11 .14 .06 .08 .05 .06 .02 .03 .04 .04 .07 .03 .03 .10 .02 -- -- -- -- -- -- -- --3195 North Coastal Orange County.13 .10 .07 .07 .06 .08 .06 .04 .04 .05 .02 .03 .03 .03 .02 .04 .02 .01 .02 .02 .01 .03 .02 .02 .02 .01RIVERSIDE COUNTY:4137 Coachella Valley 1**-- -- -- .03 .03 .01 .01 .01 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4144 Metropolitan Riverside County.08 .12 .08 .08 .07 .02 .02 .02 .02 .02 .02 .04 .02 .02 .03 .02 .02 .02 .02 .01 .01 .04 .03 .03 .11 .024157 Coachella Valley 2**-- .02 .04 .04 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --SAN BERNARDINO COUNTY:5175 Northwest San Bernardino Valley-- -- .10 .08 .07 .04 .05 .03 .02 .02 .01 .03 .03 .03 .01 -- -- -- -- -- -- -- -- -- -- --5197 Central San Bernardino Valley 1.25 .40 .12 .14 .11 .11 .14 .06 .03 .02 .02 .03 .04 .03 .01 .05 .02 .01 .03 .02 .01 .01 .02 .01 .02 .015203 Central San Bernardino Valley 2.07 .35 .09 .08 .03 .02 .02 .02 .03 .02 .05 .07 .02 .03 .01 -- -- -- -- -- -- -- -- -- -- --District Maximum.25 .40 .19 .14 .16 .14 .14 .12 .32 .08 .13 .09 .15 .11 .31 .14 .15 .07 .04 .14 .06 .10 .14 .09 .17 .05a) Station relocated in 1986.** Salton Sea Air BasinTABLE A-19Sulfate - Percent of Sampling Days Exceeding the State Standard(≥25 μg/m3, 24-hour Average)1976-2001a)STN# LOCATION 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:60 East San Gabriel Valley 5 11 8 0 6 0 2 2 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 069 East San Fernando Valley -- -- -- -- -- -- -- -- 0 0 0 0 0 0 2 0 0 0 0 0 -- -- -- -- -- --72 South Coastal Los Angeles County -- -- ---- 10 2 2 2 0 2 2 0 2 0 0 0 0 0 0 0 0 0 0 0 2 074 West San Fernando Valley 2 5 7 0 5 0 5 0 0 0 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --75 Pomona/Walnut Valley -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --76 Southwest Coastal Los Angeles County 11 146 5 11 2 3 0 2 0 b) -- -- -- -- -- -- -- -- -- -- -- -- -- -- --80 Southeast Los Angeles County -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --84 South Central Los Angeles County 5 137 8 12 0 3 2 0 0 0 0 2 0 2 0 0 0 0 0 0 0 0 0 0 085 South San Gabriel Valley -- 13 8 5 122 3 2 0 0 0 0 2 2 0 0 0 0 2 0 0 0 0 2 0 087 Central Los Angeles 7 13 7 3 8 0 4 2 2 0 0 0 2 0 2 0 0 0 0 0 0 0 0 0 0 088 West San Gabriel Valley 8 11 8 2 7 2 4 2 2 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 090 Santa Clarita Valley -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --91 Northwest Coastal Los Angeles County 0 29 0 5 2 4 0 2 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 094 Southwest Coastal Los Angeles County -- ---- -- -- -- -- -- -- -- 2 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0ORANGE COUNTY:3176 Central Orange County 1 5 5 3 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -- -- -- -- -- --3177 North Orange County 2 5 8 3 8 2 2 0 0 0 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --3186 Saddleback Valley-- 3 2 0 0 0 0 0 0 0 0 0 0 0 0 -- -- -- -- -- -- -- -- -- -- --3190 Central Orange County 23 7 5 2 4 2 0 2 0 0 0 0 2 0 0 0 0 0 -- -- -- -- -- -- -- --3195 North Coastal Orange County 2 5 3 0 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --RIVERSIDE COUNTY:4137 Coachella Valley 1** -- -- 0 0 0 0 0 0 0 0 0 0 0 0 0 -- -- -- -- -- -- -- -- -- -- --4144 Metropolitan Riverside County 1 4 2 8 5 52 0 2 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 04146 Metropolitan Riverside County 2 -- -- -- -- -- -- -- 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 04149 Perris Valley -- -- -- -- -- -- -- 0 0 0 0 0 0 0 0 -- -- -- -- -- -- -- -- -- -- --4150 San Gorgonio Pass -- -- 0 0 0 0 0 0 0 0 0 0 0 0 0 -- -- -- -- -- -- -- -- -- -- --4155 Norco/Corona -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4157 Coachella Valley 2** -- -- 0 0 0 0 0 0 0 0 0 0 0 0 0 -- -- -- -- -- -- -- -- -- -- --SAN BERNARDINO COUNTY:5171 Southwest San Bernardino Valley -- -- -- -- -- -- -- 2 4 0 0 0 0 0 0 -- -- -- -- -- -- -- -- -- -- --5175 Northwest San Bernardino Valley 6 2 7 -- 8 2 -- 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 05181 Central San Bernardino Mountains -- -- 0 02 0 0 0 0 0 0 0 0 0 0 -- -- -- -- -- -- -- -- -- -- --5197 Central San Bernardino Valley 1 4 2 16 13 67 5 2 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 05203 Central San Bernardino Valley 2 3 2 8 810 0 3 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 05204 East San Bernardino Valley 0 0 5 0 5 2 2 0 0 0 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --a) Data from 1982 onward are based on new filter type.b) Station relocated in 1986.** Salton Sea Air BasinTABLE A-20Sulfate - Maximum 24-Hour Averages, 1976-2001a)(To Be Compared to State Standard of 25 μg/m3, 24-Hour Average)STN# LOCATION 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:60 East San Gabriel Valley 29.8 38.3 36.7 24.5 38.2 23.0 26.2 25.8 27.6 15.4 14.6 15.4 23.6 16.9 16.0 19.2 16.8 19.1 17.5 12.9 17.1 12.7 10.2 17.8 17.2 14.169 East San Fernando Valley -- -- -- -- -- -- -- -- -- 21.6 19.1 17.5 33.6 22.1 25.9 18.6 12.9 20.1 18.3 13.7 -- -- -- -- -- --72 South Coastal Los Angeles County -- -- -- -- 40.7 32.7 30.4 30.8 22.2 31.0 25.2 17.6 27.8 20.0 22.6 19.9 22.6 15.6 17.116.9 19.9 11.4 14.5 13.7 26.7 15.974 West San Fernando Valley 30.2 27.3 57.8 22.9 35.6 24.1 29.2 22.5 22.9 19.0 11.7 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --75 Pomona/Walnut Valley -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --76 Southwest Coastal Los Angeles County 37.2 43.6 44.4 36.1 34.0 26.2 37.3 24.8 26.7 24.4 b) -- -- -- -- -- -- -- -- -- ---- -- -- -- --80 Southeast Los Angeles County -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --84 South Central Los Angeles County 42.4 38.0 38.1 28.1 34.2 24.0 36.8 27.6 24.9 24.0 22.4 18.2 27.1 19.6 28.1 22.4 18.7 13.7 23.1 18.8 16.0 11.4 12.0 15.6 11.4 15.485 South San Gabriel Valley -- 40.8 47.2 30.6 34.3 27.130.8 34.8 20.6 19.2 22.1 17.8 28.1 32.0 21.1 21.6 17.0 15.5 26.2 16.3 13.7 13.1 12.0 25.6 13.1 14.587 Central Los Angeles 34.4 47.2 45.0 29.7 32.8 23.7 27.7 25.7 27.4 20.0 20.4 14.5 26.6 23.0 25.3 23.1 19.4 17.6 21.7 15.512.8 14.3 10.6 17.9 16.4 15.988 West San Gabriel Valley 33.8 38.2 53.4 26.4 38.4 27.8 26.6 26.8 25.4 20.9 15.6 14.0 24.4 18.0 28.4 20.1 11.5 18.8 14.5 13.2 12.0 11.6 9.2 16.4 13.9 13.490 Santa Clarita Valley -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --91 Northwest Coastal Los Angeles County 22.6 28.7 41.2 23.5 34.9 25.3 26.0 20.0 26.4 22.5 16.9 15.2 17.4 19.6 24.8 20.9 12.3 18.1 26.8 13.3 12.2 14.0 11.2 13.9 14.1 15.694 Southwest Coastal Los Angeles County -- -- -- ---- -- -- -- -- -- 25.2 20.6 19.0 22.6 24.8 24.7 17.6 20.5 26.7 20.4 18.4 14.4 13.5 18.8 16.2 20.6ORANGE COUNTY:3176 Central Orange County 1 29.3 37.7 30.7 24.4 37.2 24.7 22.6 24.4 20.1 19.4 18.5 14.6 23.1 17.7 18.3 20.6 16.0 15.3 14.5 12.8 -- -- -- -- -- --3177 North Orange County 26.0 34.5 34.7 26.2 35.0 25.6 28.8 19.7 21.9 22.8 10.1 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --3186 Saddleback Valley22.6 32.9 26.7 21.5 21.2 20.0 13.4 21.2 14.9 21.2 14.9 14.3 16.2 16.5 13.4 -- -- -- -- -- -- -- -- -- -- --3190 Central Orange County 235.9 37.0 31.0 26.6 34.6 26.0 24.5 26.3 19.5 22.4 23.6 18.2 27.3 17.4 16.8 16.9 16.0 14.7 -- -- -- -- -- -- -- --3195 North Coastal Orange County 28.2 37.8 27.2 24.2 13.5 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --RIVERSIDE COUNTY:4137 Coachella Valley 1** 16.7 12.1 13.9 12.0 11.9 12.8 11.4 13.3 8.9 9.1 8.8 10.4 11.2 12.1 5.6 -- -- -- -- -- -- -- -- -- -- --4144 Metropolitan Riverside County 1 44.3 33.4 55.9 28.1 39.230.4 23.1 27.7 22.8 21.0 18.4 16.1 23.6 16.9 19.9 14.8 12.3 13.7 20.4 26.3 14.9 13.1 10.1 10.7 11.0 10.74146 Metropolitan Riverside County 2 -- -- -- -- -- -- -- 27.522.6 21.1 18.5 19.7 19.0 16.6 19.3 12.8 12.1 15.1 15.7 22.9 17.0 10.4 12.8 10.6 10.2 9.24149 Perris Valley -- -- -- -- -- -- -- 17.9 15.9 14.1 14.0 15.6 11.5 15.9 12.9 -- -- -- -- -- -- -- -- -- -- --4150 San Gorgonio Pass 31.6 15.6 20.7 20.0 18.5 19.6 22.9 20.1 22.2 12.3 11.3 15.2 10.6 13.8 8.6 -- -- -- -- -- -- -- -- -- -- --4155 Norco/Corona -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4157 Coachella Valley 2** 19.9 10.6 11.4 13.9 16.9 13.5 11.7 12.3 11.7 8.4 7.9 10.3 8.4 18.3 7.0 -- -- -- -- -- -- -- -- -- -- --SAN BERNARDINO COUNTY:5171 Southwest San Bernardino Valley 48.6 29.4 30.0 -- ---- -- 27.2 28.3 18.5 19.8 17.8 21.1 16.4 19.9 -- -- -- -- -- -- ---- -- -- --5175 Northwest San Bernardino Valley 34.0 64.7 37.0 32.0 ---- -- 25.5 22.6 15.3 15.7 18.0 18.5 13.9 18.7 19.0 13.2 17.1 15.812.5 13.6 9.7 10.5 11.7 11.5 10.75181 Central San Bernardino Mountains 8.2 13.2 9.8 13.9 37.3 14.2 13.3 10.3 10.3 7.1 8.0 13.1 13.4 10.2 6.6 -- -- -- -- -- ---- -- -- -- --5197 Central San Bernardino Valley 1 32.7 30.2 51.7 32.8 40.0 42.4 32.5 33.1 23.8 16.4 18.1 18.7 28.1 14.9 18.3 20.2 13.4 16.7 15.5 13.4 13.6 10.2 10.1 12.4 10.7 10.75203 Central San Bernardino Valley 2 27.5 28.5 47.1 31.742.8 38.8 29.6 27.1 23.4 19.4 17.8 17.6 15.8 17.8 17.3 18.3 12.9 17.2 14.9 12.5 11.2 9.1 11.5 10.9 12.4 12.45204 East San Bernardino Valley 21.5 23.7 32.7 23.7 37.3 31.0 28.5 24.1 21.0 16.2 9.9 -- -- -- -- -- -- -- -- -- -- -- -- ---- --District Maximum48.6 64.7 57.8 36.1 42.8 42.4 37.3 34.8 28.3 31 25.2 20.6 33.6 32 28.4 24.7 22.6 20.5 26.8 26.3 19.9 14.4 14.5 25.6 26.7 20.6a) Data from 1982 onward are based on new filter type.b) Station relocated in 1986.** Salton Sea Air BasinTABLE A-21Lead - Highest Calendar Quarter Mean, μg/m3(To Be Compared to Federal Standard of 1.5 μg/m3, Calendar Quarter Average)1976-2001STN# LOCATION1976 1977 1978 1979 198 1981 1982 1983 1984 1985 1986 1987 1988 1989 199 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:60 East San Gabriel Valley 1.96 2.68 1.44 1.08 0.91 0.74 0.69 0.50 0.43 0.21 0.18 -- -- -- -- -- -- -- -- -- -- -- -- -- ----69 East San Fernando Valley -- -- -- -- -- -- -- -- 0.650.49 0.33 0.20 0.20 0.10 0.07 0.07 0.09 0.05 0.05 0.04 -- -- -- ---- --72 South Coastal Los Angeles County -- -- -- -- -- 1.120.92 0.70 0.69 0.36 0.31 0.22 0.15 0.08 0.07 0.07 0.05 0.05 0.04 0.04 0.08 0.03 0.04 0.05 0.04 0.0474 West San Fernando Valley 3.37 3.40 2.42 1.73 1.68 0.97 0.79 0.67 0.55 0.27 0.15 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --75 Pomona/Walnut Valley -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- - -- -- -- -- -- -- -- -- --76 Southwest Coastal Los Angeles County 7.52 5.34 4.06 3.21 2.55 1.57 1.63 1.03 1.02 0.60 a) -- -- -- -- -- -- -- -- -- ---- -- -- -- --80 Southeast Los Angeles County -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --84 South Central Los Angeles County 5.30 4.59 3.27 2.98 2.15 1.40 1.36 1.03 1.02 0.63 0.44 0.24 0.19 0.11 0.11 0.10 0.08 0.06 0.07 0.06 0.05 0.07 0.04 0.09 0.06 0.1285 South San Gabriel Valley -- 5.52 2.77 2.00 1.96 1.271.12 0.86 0.72 0.49 0.40 0.26 0.22 0.12 0.11 0.14 0.10 0.11 0.08 0.06 0.06 0.06 0.05 0.09 0.06 0.0587 Central Los Angeles 3.76 4.46 2.38 2.69 2.04 1.30 1.04 0.80 0.72 0.47 0.28 0.18 0.14 0.12 0.09 0.14 0.11 0.07 0.07 0.060.06 0.07 0.04 0.07 0.05 0.0588 West San Gabriel Valley 4.49 4.37 3.01 2.28 1.65 1.08 0.73 0.56 0.56 0.29 0.19 -- -- -- -- -- -- -- -- -- -- -- -- -- ----90 Santa Clarita Valley -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --91 Northwest Coastal Los Angeles County 2.17 2.14 2.00 1.81 1.68 1.28 0.89 0.60 0.58 0.26 0.15 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --94 Southwest Coastal Los Angeles County -- -- -- -- ---- -- -- -- -- 0.25 0.17 0.11 0.07 0.06 0.06 0.05 0.04 0.04 0.04 0.03 0.05 0.04 0.04 0.05 0.04ORANGE COUNTY:3176 Central Orange County 1 3.49 3.28 2.00 1.60 1.44 0.90 0.75 0.54 0.56 0.27 0.20 0.13 0.09 0.08 0.06 0.06 0.03 0.04 0.03 0.04 -- -- -- -- -- --3177 North Orange County 3.46 3.20 2.11 1.67 1.34 0.97 0.88 0.59 0.58 0.33 0.18 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --3186 Saddleback Valley-- 1.58 0.85 0.65 0.60 0.41 0.32 0.27 0.24 0.15 0.09 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --3190 Central Orange County 24.57 3.25 2.70 2.08 1.52 0.85 0.97 0.55 0.60 0.31 0.22 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --3195 North Coastal Orange County 3.39 2.66 2.00 1.38 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --RIVERSIDE COUNTY:4137 Coachella Valley 1** -- -- 0.47 0.34 0.25 0.21 0.13 0.12 0.14 0.10 0.06 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4144 Metropolitan Riverside County 1 2.31 1.95 1.53 1.18 0.840.64 0.46 0.41 0.40 0.21 0.16 0.12 0.07 0.050.05 0.05 0.03 0.04 0.04 0.04 0.04 0.04 0.04 0.05 0.05 0.034146 Metropolitan Riverside County 2 -- -- -- -- -- -- -- 0.540.55 0.30 0.21 0.14 0.09 0.06 0.05 0.06 0.03 0.04 0.03 0.03 0.03 0.04 0.05 0.04 0.03 0.034149 Perris Valley -- -- -- -- -- -- -- 0.25 0.26 0.13 0.10 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4150 San Gorgonio Pass -- -- 0.50 0.49 0.27 0.23 0.23 0.17 0.18 0.09 0.08 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4155 Norco/Corona -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4157 Coachella Valley 2** -- -- 0.50 0.36 0.28 0.22 0.13 0.17 0.20 0.14 0.12 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --SAN BERNARDINO COUNTY:5171 Southwest San Bernardino Valley -- -- -- -- -- ---- 0.36 0.50 0.26 0.17 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --5175 Northwest San Bernardino Valley 2.07 1.84 1.35 1.09 ---- -- 0.47 0.36 0.23 0.17 0.11 0.07 0.08 0.05 0.07 0.04 0.04 0.040.04 0.04 0.04 0.04 0.05 0.05 0.045181 Central San Bernardino Mountains -- 1.02 -- 0.35 0.26 0.19 0.15 0.13 0.13 0.07 0.05 -- -- -- -- -- -- -- -- -- -- -- ---- -- --5197 Central San Bernardino Valley 1 1.40 1.53 0.99 0.870.60 0.46 0.46 0.35 0.27 0.17 0.16 -- -- -- -- -- -- -- -- -- -- ---- -- -- --5203 Central San Bernardino Valley 2 1.87 1.41 2.47 1.221.04 0.73 0.51 0.41 0.37 0.20 0.19 0.13 0.08 0.07 0.05 0.05 0.04 0.04 0.04 0.04 0.04 0.04 0.03 0.05 0.05 0.045204 East San Bernardino Valley 1.33 1.80 1.06 0.66 0.45 0.36 0.32 0.27 0.22 0.15 0.07 -- -- -- -- -- -- -- -- -- -- -- -- ---- --District Maximum7.52 5.52 4.06 3.21 2.55 1.57 1.63 1.03 1.02 0.63 0.44 0.26 0.22 0.12 0.11 0.14 0.11 0.11 0.08 0.06 0.08 0.07 0.05 0.09 0.06 0.12a) Station relocated in 1986.** Salton Sea Air BasinTABLE A-22Lead - Highest Monthly Averages, μg/m3(To Be Compared to State Standard of 1.5 μg/m3, Monthly Average)1976-2001STN# LOCATION1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001LOS ANGELES COUNTY:60 East San Gabriel Valley 2.27 3.06 1.59 1.48 1.45 0.92 0.72 0.55 0.45 0.25 0.19 -- -- -- -- -- -- -- -- -- -- -- -- -- ----69 East San Fernando Valley -- -- -- -- -- -- -- -- 0.900.60 0.41 0.29 0.35 0.20 0.08 0.10 0.16 0.05 0.06 0.05 -- -- -- ---- --72 South Coastal Los Angeles County -- -- -- -- 2.01 1.22 1.09 1.08 0.94 0.52 0.43 0.33 0.21 0.11 0.09 0.08 0.07 0.06 0.060.05 0.08 0.05 0.07 0.06 0.05 0.0574 West San Fernando Valley 3.96 4.50 3.05 2.24 1.71 1.62 1.01 0.96 0.68 0.32 0.19 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --75 Pomona/Walnut Valley -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --76 Southwest Coastal Los Angeles County 10.04 6.77 5.48 3.91 3.44 1.91 1.70 1.29 1.38 0.90 a) -- -- -- -- -- -- -- -- -- ---- -- -- -- --80 Southeast Los Angeles County -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --84 South Central Los Angeles County 8.13 5.74 4.42 3.67 3.02 1.83 1.55 1.36 1.43 0.91 0.58 0.32 0.31 0.15 0.14 0.17 0.11 0.08 0.09 0.07 0.09 0.07 0.04 0.17 0.09 0.2385 South San Gabriel Valley -- 6.68 4.02 2.24 2.34 1.591.18 1.14 0.93 0.65 0.57 0.31 0.29 0.19 0.13 0.19 0.15 0.15 0.10 0.07 0.09 0.08 0.07 0.21 0.09 0.0787 Central Los Angeles 4.90 5.06 2.71 2.82 2.68 1.75 1.05 1.04 0.89 0.61 0.42 0.23 0.22 0.17 0.09 0.21 0.16 0.10 0.11 0.070.08 0.07 0.06 0.13 0.06 0.0688 West San Gabriel Valley 5.61 4.73 4.16 2.54 1.72 1.43 0.90 0.84 0.73 0.38 0.24 -- -- -- -- -- -- -- -- -- -- -- -- -- ----90 Santa Clarita Valley -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --91 Northwest Coastal Los Angeles County 2.98 2.63 2.90 2.17 2.02 1.83 1.00 0.82 0.78 0.33 0.23 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --94 Southwest Coastal Los Angeles County -- -- -- -- ---- -- -- -- -- 0.35 0.26 0.18 0.13 0.08 0.08 0.05 0.05 0.05 0.04 0.04 0.06 0.06 0.05 0.08 0.04ORANGE COUNTY:3176 Central Orange County 1 4.62 4.60 2.96 1.90 2.05 1.13 0.78 0.72 0.65 0.32 0.27 0.14 0.11 0.15 0.10 0.08 0.05 0.07 0.06 0.04 -- -- -- -- -- --3177 North Orange County 4.55 4.07 3.20 1.89 1.72 1.31 0.96 0.95 0.71 0.44 0.23 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --3186 Saddleback Valley2.11 2.66 1.36 0.72 0.69 0.61 0.36 0.32 0.31 0.20 0.10 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --3190 Central Orange County 26.38 4.68 4.04 2.71 1.88 1.14 1.08 0.93 0.86 0.39 0.28 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --3195 North Coastal Orange County 4.16 3.63 3.11 1.90 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --RIVERSIDE COUNTY:4137 Coachella Valley 1** -- -- 0.73 0.44 0.35 0.31 0.18 0.16 0.17 0.13 0.10 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4144 Metropolitan Riverside County 1 2.94 2.45 1.80 1.30 1.070.85 0.55 0.57 0.54 0.27 0.17 0.14 0.10 0.070.08 0.06 0.03 0.05 0.06 0.04 0.088 0.07 0.08 0.06 0.06 0.044146 Metropolitan Riverside County 2 4.37 3.90 -- -- -- -- --0.77 0.65 0.37 0.24 0.18 0.12 0.07 0.08 0.080.03 0.04 0.04 0.05 0.05 0.07 0.10 0.05 0.04 0.034149 Perris Valley -- -- -- -- -- -- -- 0.28 0.31 0.18 0.11 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4150 San Gorgonio Pass -- -- 0.59 0.61 0.31 0.27 0.27 0.24 0.21 0.10 0.10 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4155 Norco/Corona -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --4157 Coachella Valley 2** -- -- 0.63 0.52 0.36 0.40 0.16 0.24 0.24 0.19 0.16 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --SAN BERNARDINO COUNTY:5171 Southwest San Bernardino Valley 5.30 -- -- -- -- ---- 0.44 0.67 0.36 0.22 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --5175 Northwest San Bernardino Valley 2.60 2.47 1.68 1.43 ---- -- 0.54 0.43 0.26 0.20 0.13 0.10 0.11 0.07 0.08 0.04 0.05 0.050.06 0.04 0.04 0.05 0.07 0.07 0.055181 Central San Bernardino Mountains 0.30 0.78 0.36 0.48 0.31 0.29 0.18 0.17 0.14 0.12 0.08 -- -- -- -- -- -- -- -- -- -- ---- -- -- --5197 Central San Bernardino Valley 1 2.10 3.15 1.19 1.200.86 0.52 0.53 0.39 0.34 0.22 0.17 -- -- -- -- -- -- -- -- -- -- ---- -- -- --5203 Central San Bernardino Valley 2 2.40 1.83 3.33 1.491.30 1.01 0.62 0.52 0.47 0.31 0.23 0.15 0.12 0.09 0.07 0.06 0.05 0.05 0.04 0.05 0.06 0.04 0.05 0.07 0.06 0.055204 East San Bernardino Valley 1.80 1.59 1.25 0.82 0.57 0.47 0.34 0.32 0.30 0.19 0.10 -- -- -- -- -- -- -- -- -- -- -- -- ---- --Disctrict Maximum10.04 6.77 5.48 3.91 3.44 1.91 1.70 1.36 1.43 0.91 0.58 0.33 0.35 0.20 0.14 0.21 0.16 0.15 0.11 0.07 0.09 0.08 0.10 0.21 0.09 0.23a) Station relocated in 1986.** Salton Sea Air Basin