# 2010 Annual Monitoring Network Plan

Prepared by the Air Monitoring Section of Antelope Valley Air Quality Management District to meet the requirements of 40 CFR PART 58 , SUBPART B.

Eldon Heaston, Executive Officer Bret Banks , Manager Christopher A. Collins, Supervisor Aleksey Astakhov, Air Quality Instrument Technician Fred Wohosky, Air Quality Instrument Technician Orlando Salinas, Associated Air Quality Specialist

Antelope Valley Air Quality Management District, 43 301 Division Street, Suite 206, Lancaster CA.
935352 

### Table of Contents

40 CFR PART 58, SUBPART B

REQUIREMENTS.................................................

................................................... .......................3

ABOUT THE ANTELOPE VALLEY AIR QUALITY MANAGEMENT DI STRICT ................4

NETWORK DESIGN ....................................

................................................... ........................................5

OVERVIEW OF MDAQMD MONITORING STATIONS ............ .................................................5

CRITERIA POLLUTANT STANDARDS ...................... ............................................................6

INDIVIDUAL SITE DATA:

LANCASTER .........................................

................................................... ............................................7

EPA OZONE MAPPING

................................................... ................................................... ................................................... ...........9

APPENDIX:

DEFINITION OF
TERMS..............................................

................................................... ................................................10

CRITERIA POLLUTANT INFORMATION.....................

................................................... ............12

NATIONAL AMBIENT AIR QUALITY STANDARD.............. .....................................................143 

### 40 CFR Part 58, Subpart B Requirement

This 2010 Annual Air Monitoring Network Review is b eing submitted by the Antelope Valley Air Quality Management District’s Air Monitoring Sectio n to the United States Environmental Protection Agency (US EPA) Region 9. The network review evalua tes the adequacy of the ambient air monitoring network with respect to the monitoring objectives a nd spatial scales. This annual assessment is requir ed by 40 CFR Part 58, Subpart B. This Network Review i s also preliminary to the annual data certification with the US EPA and helps Air Districts assess the quality of their data before submitting for data
certification. This network review has the secondar y purpose of informing the public of the criteria a ir pollutants that can affect their health, how the Mo jave Desert AQMD monitors these criteria pollutants

, and what the actual readings are so that our citize ns can make informed decisions regarding their lifestyles.4 

### About the Antelope Valley Air Quality Management Di strict

The AVAQMD comprises over 1,300 square miles. From the Kern County line on the north, the San Gabriel and Tehachapi Mountains to the south and we st and the San Bernardino County line to the east nearly 400,000 inhabitants depend on air quality re gulation for healthful, cleaner air.

For decades the Antelope Valley air quality was man aged by a regional air quality organization that wa s 100 miles away and of a totally different mind set. The dream of local business people was realized w hen state legislation created the Antelope Valley Air P ollution Control District, on July 1, 1997. On Jan uary 1, 2002, the AV Air Pollution Control District brok e away from the County of Los Angeles and became the AV Air Quality Management District, an independ ent agency. Today, AVAQMD is responsible for regulating stationary sources of air pollution loca ted within its 1,300 square mile jurisdiction.

For the first time, there were local officials and local staff to which Antelope Valley citizens and businesses could turn for assistance. Consisting o f representatives from local cities, Los Angeles Co unty and the public at large, the District worked hard t o simplify rules and eliminate regulations that sim ply did not apply to the desert air shed quality issues.5 

### NETWORK DESIGN

Purpose and Objective of the Network The purpose of the ambient air monitoring network i s to assess the extent of air pollution, ensure compliance with national legislation, evaluate cont rol options, and provide data for air quality model ing. In general, six basic monitoring objectives and fiv e measuring scales are used to determine the networ k design (see Table 2 and Table 3). Additional consid erations such as availability of power, accessibili ty to site, security, geographic location, and fiscal and personnel resources are also addressed in determin ing the feasibility of the network design.

Table 2 Site Monitoring Objectives 1. Determine highest concentrations expected to occ ur in the area covered by the network. 2. Determine representative concentrations in areas of high population density. 3. Determine the impact on ambient pollution levels of significant sources or source categories. 4. Determine general background concentration level s. 5. Determine the extent of regional pollutant trans port from populated areas, with regards to the secondary standards (such as visibility impairment and effects on vegetation). 6. Determine the welfare-related impacts in more ru ral and remote areas.

To establish or evaluate a site, one must link its monitoring objectives to the physical location of t he site. This can be done by matching the spatial scale, whi ch represents the sample of air around the monitor where pollutant concentrations are reasonably unifo rm, with the most appropriate monitoring objective. Thus, spatial scale represents the physical dimensi ons of the air parcel around the monitor, and monitoring objective represents the overall purpose of the monitor. Combining the proper spatial scale with the monitoring objective explains why air moni toring sites are located in particular areas.

Table 3 Spatial Measurement Scales

Scale Defined parameter (radius)

Micro Scale 0 to 100 meters

Middle Scale 100 to 500 meters Neighborhood Scale 0.5 to 4 kilometers

Urban Scale 4 to 50 kilometers Regional Scale 10 to 100s of kilometers

Since it is physically and fiscally impossible to m onitor air quality in every location, representativ e samples must be obtained. The optimal locations for obtaining these samples are determined by using th e monitoring objectives and the spatial measurement s cales described above. For example, there might be numerous locations where the highest concentration of particulate matter may occur. Using these principles, only one or two sites will be establish ed to represent all of the high-concentration areas . The same reasoning can be used for different types of pollutants. This does not mean that the nu mber of monitoring sites is fixed. To the contrary, the network must be dynamic enough to maintain a curren t representative sample of the air quality.



### Overview of the AVAQMD Monitoring Station

AVAQMD currently operates a network of 1 monitoring site. The following is a brief description of that
site:

Lancaster this site is located at 43301 Division Street, Lanc aster, CA. This represents the most densely populated area in the Antelope Valley Desert Air Basin.6 

### Criteria Pollutant Standards

Carbon Monoxide (CO) There are two primary standards for CO, the 8-hour average and the 1-hour average. The 8-hour primary standard is 9 ppm and the 1-hour primary standard i s 35 ppm. A violation of the standard is any two exceedances in a calendar year.

Ozone (O3) The 1-hour average ozone standard was revoked by th e EPA on June 15, 2005, and has been replaced by the 8-hour average standard for compliance purposes

. The eight-hour primary standard for ozone is 0.075 ppm. Compliance with the standard is determined by averaging the 4th highest eight-hour average over a three-year period. This three-year average must be less than or equal to 0.075 ppm

Particulate Matter <=10 Microns (PM10) The 24-hour Primary standard for PM10 is 150 μg/m3 (155 μg/m3 with mathematical rounding). This standard is violated when the expected number of ex ceedance for the calendar year is more than one. A formula, as detailed in 40 CFR 50, is used to deter mine the expected number of exceedances. The formul a takes into account the number of days sampling occu rred and the number of valid samples collected. A 3

- year average of these estimated days is then used t o determine compliance. On December 18, 2006 new monitoring rules from the EPA revoked the PM10 annual primary standard

Particulate Matter <=2.5 Microns (PM2.5) On December 18, 2006, the EPA implemented new prima ry standards for PM2.5. These new rules changed the 24-hour average standard from 65 μ g/m3 to 35 μ g/m3. The annual average standard of 15

μ g/m3 remains unchanged. Compliance with the 24-hour standard is determined by taking the 3-year average of the 98th percentile at each monitoring site. Compliance with the Annual st andard is determined by taking the 3-year average o f the spatially averaged annual means.

Nitrogen Dioxide (NO2) Compliance with the NO2 standard is achieved when t he annual arithmetic mean concentration in a calendar year is less than or equal to 0.053 ppm, r ounded to three decimal places.

Sulfur Dioxide (SO2) A violation of the primary standard occurs when the annual mean exceeds 0.030 ppm or when a 24-hour average of 0.14 ppm is exceeded more than once per calendar year. A violation of the 3-hour average secondary standard occurs when a 3-hour average of 0.5 ppm is exceeded more than once per year7

AQS ID 060379033
GIS COORDINATES N34deg. 40’10”, W118deg. 7’50”
LOCATION AVAQMD Building
ADDRESS 43301 Division St.
COUNTY Los Angeles County
DISTANCE TO ROAD 25 Meters
TRAFFIC COUNT 30000
GROUND COVER Roof
FLOW AUDIT 4/2/2009
REPRESENTATIVE AREA Desert portion of Los Angeles County

Pollutant 03 N02 S02 C0 PM10 PM2.5 TEOM WDR Monitor Objective Transport Population Population Population N/A N/A N/A N/A Monitor Purpose SLAMS SLAMS SLAMS SLAMS SLAMS SLAMS SLAMS SLAMS Spatial Scale NBHD NBHD NBHD NBHD NBHD NBHD NBHD NBHD Sampling Method API 400 API 200A API 100A API 300A ANDR R&P 2000 R& P
1400A CLIMA

Analysis Method UV ABS CHEM FLUOR GFC MDLAB MDLAB MICRO AERO

Start Date May - 01 May - 01 May - 01 May - 01 May - 01 May - 01 May - 01 May - 01 Operation Schedule CONTIN CONTIN CONTIN CONTIN 1:6 1:6 CONTIN CONTIN Sampling Season All Year All Year All Year All Year All Year All Ye ar All Year All Year Probe Height (meters) 9.4 9.4 6.9 9.4 9.0 9.0 9.0 13.6

Distance from supporting structure N/A N/A N/A N/A N/A N/A N/A N/A

Distance from
obstruction on roof N/A N/A N/A N/A N/A N/A N/A N/A

Distance from structures

not on roof N/A N/A N/A N/A N/A N/A N/A N/A

Distance from trees N/A N/A N/A N/A N/A N/A N/A N/A

Distance between

collocated monitors N/A N/A N/A N/A N/A 2 meters N/A N/A

Unrestricted airflow (deg) 360 deg 360 deg 360 deg 360 deg 360 deg 360 deg 360 deg 360 deg

Probe Material TEFLON TEFLON TEFLON TEFLON TEFLON TEFLON TEFLON TE FLON Residence Time (sec) 14.2 15.4 16.3 13.8 N/A N/A N/A N/A Changes within the next
18 months NO NO NO NO NO NO NO NO

Suitable for comparison
to the annual PM2.5? N/A N/A N/A N/A N/A YES N/A N/A

*CHEM Chemluminescence *FLUOR Fluorescence

*GFC Gas filter Correlation *MDLAB MDAQMD LAB
*NBHD Neighborhood *MICRO Microbalance

*ANDR Andersen *CLIMA Climatronics

*AERO Aero vane *PYRAN Pyranometer

*THERM Thermistor *CONTIN Continuous

*PIEZO Piezoresistive

*UV ABS UV ABSORPTION

*ANEMO Anemometer 5 YEAR TREND OXONE EXCEEDANCES

STATE

1HR. STATE

8HR. FED

1HR FED
8HR.

2005 22 2 16

2006 16 0 14

2007 18 59 0 39

2008 22 70 0 46

2010
NUMBER OF OCCURANCES8

AQS ID 060379033
GIS COORDINATES N34deg. 40’10”, W118deg. 7’50”
LOCATION AVAQMD Building
ADDRESS 43301 Division St.
COUNTY Los Angeles County
DISTANCE TO ROAD 25 Meters
TRAFFIC COUNT 30000
GROUND COVER Roof
FLOW AUDIT 4/2/2009
REPRESENTATIVE AREA Desert portion of Los Angeles County

Pollutant WSP TMP PRESS Monitor Objective N/A N/A N/A Monitor Purpose SLAMS SLAMS SLAMS Spatial Scale N/A N/A N/A Sampling Method CLIMA CLIMA CLIMA Analysis Method ANEMO THERM PIEZO

Start Date May - 01 May - 01 May - 01
Operation Schedule CONTIN CONTIN CONTIN Sampling Season All Year All Year All Year Probe Height (meters) 13.6 15.9 1.5

Distance from supporting structure N/A N/A N/A

Distance from

obstruction on roof N/A N/A N/A

Distance from structures

not on roof N/A N/A N/A

Distance from trees N/A N/A N/A

Distance between
collocated monitors N/A N/A N/A

Unrestricted airflow (deg) 360 deg 360 deg 360 deg

Probe Material TEFLON TEFLON TEFLON Residence Time (sec) N/A N/A N/A Changes within the next
18 months NO NO NO

Suitable for comparison
to the annual PM2.5? N/A N/A N/A

*CHEM Chemluminescence *FLUOR Fluorescence

*GFC Gas filter Correlation *MDLAB MDAQMD LAB
*NBHD Neighborhood *MICRO Microbalance

*ANDR Andersen *CLIMA Climatronics

*AERO Aerovane *PYRAN Pyranometer

*THERM Thermistor *CONTIN Continuous

*PIEZO Piezoresistive

*UV ABS UV ABSORPTION

*ANEMO Anemometer9 Figure 1: Looking at station from the NorthWest

Figure 2: Looking at proves from the North.

Figure 3: Looking at probes from the East.

PM 10 Sampler PM 2.5 Sampler

Gas sample probe

TEOM sample probe.10 

### EPA Ozone Mapping The AIRNOW website ( http://www.epa.gov/airnow ) provides real-time air pollution (ozone and PM2.5 ) maps for major metropolitan areas around the United States, including the Mojave Desert Air Quality Management District. The MDAQMD has participated i n the program since 2001.

This website can be used as a tool for which the pu blic can plan their daily activities and limit thei r exposure to air pollution. Eight-hour average peak ozone concentration maps and real-time eight-hour ozone animation maps are provided. Colors on the ma p indicate different concentrations of ozone pollution. The one-hour average values are given in parts per billion. The eight-hour averages are converted into Air Quality Index (AQI) numbers. The AQI is based on the NAAQS. The index was developed to convert pollution measurements into a common index that the general public can more easily understand.

Air Quality Index
Levels of Health Concern Numerical
Value Meaning

Good (GREEN) 0-50 Air quality is considered satisfactory, and air pol lution poses little
or no risk.

Moderate (YELLOW) 51-100 Air quality is acceptable; however, for some pollut ants there may be a moderate health concern for a very small numbe r of people who are unusually sensitive to air pollution.

Unhealthy for Sensitive Groups (ORANGE) 101-150 Members of sensitive groups may experience health e ffects. The general public is not likely to be affected.

Unhealthy (RED) 151-200 Everyone may begin to experience health effects; me mbers of sensitive groups may experience more serious health effects.

Very Unhealthy (PURPLE) 201-300 Health alert: everyone may experience more serious health
effects.

Hazardous (MAROON) > 300 Health warnings of emergency conditions. The entire population is more likely to be affected.11 

### DEFINITION OF TERMS

AQS: Environmental Protection Agency’s Air Quality Syste m

Attainment: This refers to the NAAQS used to comply with the fe deral Clean Air Act. After several years of no violations of the NAAQS, the EPA can cl assify the area as in attainment for that pollutant

.

CFR: Code of Federal Regulations.

Class I: Federally designated park or wilderness area with m andated visibility protection.

CO: Carbon monoxide.

Criteria Pollutants: Six pollutants (CO, Lead, NO2, O3, Particulates, an d SO2) that have NAAQS established by the US EPA.

Delta T: Difference between two levels of temperature measur ements.

Design Value: A design value is a statistic that describes the ai r quality status of a given area relative to the level of the NAAQS. For a concentration-based s tandard, the air quality design value is simply the standard-related test statistic. The design value o f a pollutant monitoring network is the highest sam ple value in the network used to compare to the NAAQS; e.g. the 24-hour PM2.5 design value for the network is the monitor with the highest 3-year aver age of the 98th percentile.

EPA: U. S. Environmental Protection Agency.

Exceptional Events: An uncontrollable event caused by natural sources o f pollution or an event that is not expected to recur at a given location.

HAPs: Hazardous air pollutants. An air-born chemical that has been listed in the federal Clean Air Act and has an associated standard or process requireme nt determined for it.

AVAPCD: Antelope Valley Air Quality Management District

μg/m3: Microgram per cubic meter.

MSA: Metropolitan Statistical Area. A geographical area designated by the federal government based on the concept of a core area with a large population nucleus, plus adjacent communities having a high degree of economic and social integration with that core.

NAAQS: National Ambient Air Quality Standards. A health an d welfare-based standard that is set by the US EPA to qualify allowable levels of criteria poll utants.

NO2: Nitrogen dioxide.

NOX : Sum of nitrogen oxide and NO2.
O3: Ozone.

Pb: Lead.12

PM: Particulate matter. Material suspended in the air i n the form of minute solid particles or liquid droplets.

PM2.5: Particulate matter of 2.5 Microns in diameter or sm aller

PM10: Particulate matter of 10 Microns in diameter or sma ller.

PPM: Parts per million.

Primary Standard: One portion of the NAAQS. These standards are desig ned to protect the public
health.

Secondary Standard: The less stringent portion of the NAAQS designed to protect property and the
environment.

SIP: State Implementation Plan. SIPs are a collection of state and local regulations and plans to achieve healthy air quality under the Clean Air Act

.

SLAMS: State and Local Air Monitoring Station. The SLAMS c onsist of a network of approximately 5,000 monitoring stations nationwide whose size and distribution is largely determined by the needs of State and local air pollution control agencies to m eet their respective State implementation plan (SIP ) requirements. Other types of monitoring stations in clude NCORE (national core) and SPM (special purpose) monitors

SO2: Sulfur dioxide.

SPM: Special purpose monitor. Special Purpose Monitoring Stations provide for special studies needed by the State and local agencies to support S tate implementation plans and other air program activities. The SPMs are not permanently es tablished and can be adjusted easily to accommodate changing needs and priorities.

SSI: Size Selective Inlet. SSI High Volume Samplers are filter-based instruments to measure PM10.

TEOM: Tapered Element Oscillating Microbalance. A continu ous particulate measuring instrument used

to measure PM10.

VOC: Volatile organic compounds. VOCs are chemical compo unds that can easily vaporize and enter the atmosphere. There are many natural and artificial s ources of VOCs; solvents and gasoline make up some of the largest artificial sources. VOCs will react with NOx in the presence of sunlight to create grou ndlevel ozone pollution.13 

### CRITERIA POLLUTANT INFORMATION

Abstract of Pollutants: Certain air pollutants, called “criteria air pollut ants,” are common throughout the United States. These pollutants can cause health pr oblems, pollute the environment, and cause property damage. These criteria pollutants are so named sinc e the US EPA has regulations, called the National Ambient Air Quality Standards (NAAQS), on allowable levels of these substances using health-b ased criteria. One set of limits, called “primary standards”, protect health, while another set of “s econdary” standards, is designed to protect propert y and
the environment. The US EPA names the following pollutants as criter ia pollutants: carbon monoxide (CO), lead (Pb), nitrogen dioxide (NO2), ozone (O3), particulates (P M10 & PM2.5), and sulfur dioxide (SO2). MDAQMD operates monitors for the following criteria pollut ants: carbon monoxide, ozone, particulates, nitroge n dioxide, and sulfur dioxide. MDAQMD does not monitor for lead (Pb)

Causes and Characteristics of Pollutants
Carbon Monoxide: CO is the most widely distributed and most commonly occurring air pollutant. Total emissions of CO to the atmosphere exceed all other pollutants combined , on a weight basis. Fortunately, CO does not persi st in the atmosphere, but is quickly converted to carb on dioxide (CO2). CO can reach dangerous levels in localized areas or hotspots such as heavily travele d intersections or city streets. In addition, CO ha s been implicated in ozone formation. Most people are fami liar with CO and are aware that automobiles produce this deadly odorless and colorless gas. In fact, t his gas is produced almost anytime something is bur ned. All substances that are living (plants, animals) or that were once living (wood, c oal, oil, gasoline) are composed of carbon compound s. If these substances are burned in the presence of s ufficient oxygen, the carbon is converted to CO2 ga s. If, as is often the case, not enough oxygen is present, carbon monoxide gas is produced. Carbon monoxide’ s danger lies in the extremely strong affinity that h emoglobin has for it. Hemoglobin, the special oxyge ntransporting material in the red blood cell, has ap proximately 200 times stronger affinity for CO than for oxygen. Therefore, if both CO and O2 are present th e bonding between the CO and hemoglobin will prevent the O2 from exchanging within a person’s bo dy. This puts a heavy burden on people with heart disease and can aggravate angina, but even healthy people can suffer from harmful side effects from CO

.

Nitrogen Dioxide: NO2 belongs to a family of highly reactive gases ca lled nitrogen oxides. These gases are formed when fuel is burned at high temperatures, and are emitte d primarily from automobile exhaust and power plant s. Exposure to nitrogen dioxide can irritate the lungs and lower resistance to respiratory infections, particularly in people with existing respiratory il lness such as asthma.

Ozone:
O 3 is a naturally occurring compound in which three o xygen atoms combine together. This is an unstable combination, and ozone is continually going through a natural cycle of being formed and then convertin g back to the more stable “normal” double oxygen comp ound (O2). The cycle occurs fairly rapidly. In the stratosphere (6 miles and more above the earth), na turally occurring ozone has a beneficial effect of screening out harmful ultraviolet light from the su n. However, ground-level ozone is a pollutant and i s a component of the regional smog that affects the bas in. Ozone is not directly emitted into the air, but rather forms in a complex reaction that involves heat, sun light, and a “soup” of toxic pollutants, especially volatile organic compounds (VOCs).14

Some of the most common sources of VOCs are gasolin e vapors, chemical solvents, and combustion products of fuels and consumer products. Ozone is c reated by sunlight acting on nitrates (NOX) and VOCs from motor vehicles and stationary sources, an d can be carried hundreds of miles from their origins. Ozone affects the respiratory system in pe ople and animals, and also affects the growth of pl ants.

Particulate Matter: Particulate matter is the term for solid or liquid particles found in the air. Particle pollution is m ade up of a number of components, including acids (such as ni trates and sulfates), organic chemicals, metals, an d soil or dust particles. While some particles are la rge or dark enough to be seen as soot or smoke, oth ers can only be seen through an electron microscope. In 1987 the EPA replaced the Total Suspended Particulates (TSP) air quality standard with a stan dard for PM10 (particles measuring ten microns or l ess).
Health research studies have found that PM10 has th e ability to reach the lower regions of the respira tory tract, and thus can affect the respiratory system i n both humans and animals. Particulates that have h igh acid levels can cause damage to man-made materials and reduce visibility. The size of particles is directly linked to their potential for causing health problems. EPA is concerned about par ticles that are 10 micrometers in diameter or small er because those are the particles that generally pass through the throat and nose and enter the lungs. O nce inhaled, these particles can affect the heart and l ungs and cause serious health effects. EPA groups p article pollution into two categories:

• "Coarse particles," such as those found near roadwa ys and dusty industries, range in size from 2.5 to 10
microns in diameter.

• "Fine particles," such as those found in smoke and haze, have diameters smaller than 2.5 microns. Thes e particles can be directly emitted from sources such as forest fires, or they can form when gases emitt ed from power plants, industries and automobiles react in the air.

Sulfur Dioxide: SO2 is emitted (in gaseous form) largely from burni ng high-sulfur coal, oil, and diesel fuel. Because this gas is usually found in association with particulat e pollution, as SO2 is the precursor for fine sulfa te particles, separating the health effects of these t wo pollutants is difficult. Together SO2 and PM2.5 make up a major portion of the pollutant load in many ci ties, acting separately and in concert to threaten public health. SO2 contributes to respiratory illness, p articularly in children and the elderly, and aggrav ates existing heart and lung diseases. SO2 contributes t o the formation of acid rain, and it contributes to the formation of atmospheric particles that cause visib ility impairment, most noticeably in national parks

. SO2 and the pollutants formed from SO2, such as sul fate particles, can be transported over long distan ces and deposited far from the point of origin. This m eans that problems with SO2 are not confined to are as where it is emitted.

National Ambient Air Quality Standards The EPA Office of Air Quality Planning and Standard s (OAQPS) manages programs to improve air quality in areas where the current quality is unacc eptable and to prevent deterioration in areas where the air is relatively free of contamination. To accompl ish this task, OAQPS establishes the National Ambie nt Air Quality Standard (NAAQS) for each of the criter ia pollutants (see Table 1). There are two types of standards. Primary standards protect against adverse health effects; secondary standards protect against welfare effects, such as damage to farm crops and vegetation and/or damage t o buildings. Because different pollutants have diffe rent effects, the NAAQS are also different. Some pollutants have standards for both long-term and sh ort-term averaging times. The short-term standards are designed to protect against acute, or short-term, h ealth effects, while the long-term standards are established to protect against chronic health effec ts. Table 1 lists the NAAQS for six criteria pollut ants.15

` 

### Table 1 National Ambient Air Quality Standards

The NAAQS set air pollutant concentration limits fo r six pollutants, called the criteria air pollutants

, namely carbon monoxide (CO 2 ), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), ozone (O 3 ), lead (Pb),

Particulate Matter (PM 10 ) [8] and Particulate Matter (PM 2.5 ). [8]

The NAAQS for the six criteria pollutants are liste d in the table below:

National Ambient Air Quality Standards [3][4]

Primary Standard Secondary Standard

Criteria
Pollutant Concentration
Limit Averaging

Time Concentration

Limit Averaging

Time

9 ppmv ( 10 mg / m 3 ) 8-hour (1)

Carbon monoxide
35 ppmv ( 40 mg/m 3 ) 1-hour (1) None

0.03 ppmv ( 80 μ g /m 3 ) Annual

(arithmetic mean) Sulfur dioxide
0.14 ppmv ( 365 μ g/m 3 24-hour (1) 0.5 ppmv ( 1300 μ g/m 3 ) 3-hour (1)

Nitrogen dioxide 0.053 ppmv ( 100 μ g/m 3 ) Annual

(arithmetic mean) Same as primary

0.075 ppmv ( 150 μ g/m 3 ) 8-hour (2) Same as primary

Ozone
0.12 ppmv

( 235 μ g/m 3 ) 1-hour (3) Same as primary

0.15 μ g/m 3 Rolling 3-month

average Same as primary Lead

1.5 μ g/m 3 Quarterly average Same as primary

Particulate Matter (PM 10 ) 150 μ g/m 3 24-hour (4) Same as primary

15 μ g/m 3 Annual (5)

(arithmetic mean) Same as primary Particulate Matter (PM 2.5 )

35 μ g/m 3 24-hour (6) Same as primary

(1) Not to be exceeded more than once per year.

(2) The 3-year average of the fourth-highest daily maximum 8-hour average at each monitor within the
area over each year must not exceed 0.075 ppmv.16

(3a) The expected number of days per calendar year with maximum hourly averages above
0.12 ppm must be equal to or less than 1.
(3b) As of June 15, 2007, the U.S. EPA revoked the 1-hour ozone standard in all areas except
for certain parts of 10 states.
(4) Not to be exceeded more than once per year on a verage over 3 years.
(5) The 3-year average of the weighted annual mean PM 2.5 concentrations from single or multiple
community-oriented monitors must not exceed 15 μ g/m 3

. (6) The 3-year average of the 98th percentile of 24 -hour concentrations at each population-oriented

monitor within the area must not exceed 35.5 μ g/m 3

.

The units of measure used for concentrations in the above table are parts per million by volume (ppmv),
milligrams per cubic meter of air at 101.325 k Pa and 25 ° C (mg/m 3 ), and micrograms per cubic meter of
air at 101.325 kPa and 25 °C (μg/m 3 ). See Air pollutant concentrations for the conversions between gas concentrations ppmv and mg/m 3

.