San Joaquin Valley Unified Air Pollution Control District June 30, 2011

 

San Joaquin Valley Air Pollution Control District 

2011 Air Monitoring Network Plan 

June 30, 2011 

For Submittal to the U.S. Environmental Protection Agency in July 2011 
San Joaquin Valley Unified Air Pollution Control District June 30, 2011

 

San Joaquin Valley Unified Air Pollution Control District 

1990 E. Gettysburg Avenue 

Fresno, California 93726 

(559) 230-6100 

www.valleyair.org
San Joaquin Valley Unified Air Pollution Control District June 30, 2011

2010 Air Monitoring Network Plan 

 

i

TABLE OF CONTENTS 

Executive Summary ........................................................................................................ 2

Introduction: Air Monitoring Network Plan requirements ................................................. 3

Monitoring Objectives and Spatial Scales ....................................................................... 7

Ozone............................................................................................................................ 13

PAMS............................................................................................................................ 16

Particulate Matter (PM) ................................................................................................. 17

PM10 Monitors in the Valley.......................................................................................... 18

PM2.5 Monitors in the Valley......................................................................................... 23

PM Collocation Requirements....................................................................................... 30

Public Review of Changes to the PM2.5 Monitoring Network ....................................... 30

Carbon Monoxide.......................................................................................................... 30

Nitrogen Dioxide............................................................................................................ 31

Sulfur Dioxide................................................................................................................ 33

Lead .............................................................................................................................. 34

Toxics............................................................................................................................ 34

Green House Gases...................................................................................................... 35

NCore............................................................................................................................ 35

Meteorology .................................................................................................................. 35

Summary of completed changes, January 2010 – July 2011........................................ 37

Summary of planned changes, July 2011 – December 2011........................................ 37

Stockton CBSA/MSA..................................................................................................... 38

Modesto CBSA/MSA..................................................................................................... 38

Merced CBSA/MSA....................................................................................................... 38

Madera CBSA/MSA....................................................................................................... 38

Fresno CBSA/MSA........................................................................................................ 38

Hanford-Corcoran CBSA/MSA ...................................................................................... 38

Visalia-Porterville CBSA/MSA ....................................................................................... 39

Bakersfield CBSA/MSA................................................................................................. 39

Data Submission Requirements.................................................................................... 39

Acronyms, Abbreviations, and Initialisms...................................................................... 40

Appendix A: Monitoring Site Descriptions 

Appendix B: Detailed SJV Monitoring Site Information 

Appendix C: Comments and Responses 
San Joaquin Valley Unified Air Pollution Control District June 30, 2011

2010 Air Monitoring Network Plan 

 

ii

 

LIST OF FIGURES 

Figure 1 Map of Air Monitoring Sites in the San Joaquin Valley.................................... 1

LIST OF TABLES 

Table 1 SJV Areas of Representation ............................................................................ 4

Table 2 Site Identification and AQS AIRS Codes........................................................... 5

Table 3 San Joaquin Valley 2009 Population................................................................. 7

Table 4 Ambient Air Monitoring Sites in the San Joaquin Valley Air Basin (Summary).. 9

Table 5 SLAMS Minimum Ozone Monitoring Requirements ........................................ 13

Table 6 Ozone Requirements for the San Joaquin Valley............................................ 14

Table 7a San Joaquin Valley Ozone Monitors (SLAMS).............................................. 14

Table 7b San Joaquin Valley Ozone Monitors (SPM) .................................................. 16

Table 8 SJV PAMS sites .............................................................................................. 17

Table 9 Minimum PM10 Monitoring Requirements ...................................................... 19

Table 10 PM10 Monitoring requirements for the Valley................................................ 19

Table 11a San Joaquin Valley PM10 SLAMS monitor information............................... 20

Table 11b San Joaquin Valley PM10 SPM monitor information................................... 21

Table 12 San Joaquin Valley PM10 monitor types....................................................... 22

Table 13 Minimum PM2.5 Monitoring Requirements.................................................... 24

Table 14 PM2.5 Monitoring requirements for the Valley............................................... 24

Table 15a San Joaquin Valley PM2.5 SLAMS monitor information.............................. 25

Table 15b San Joaquin Valley PM2.5 SPM monitor information.................................. 27

Table 16 San Joaquin Valley PM2.5 monitor types...................................................... 28

Table 17 Carbon Monoxide Monitoring Stations in the San Joaquin Valley ................. 31

Table 18 NO2 Monitoring Stations in the San Joaquin Valley....................................... 32

Table 19a SO2 Monitoring Station in the San Joaquin Valley....................................... 33

Table 19b Populations Weighted Emissions Index for the San Joaquin Valley............ 34

Table 20 Meteorological Parameter Monitoring Stations in the San Joaquin Valley .... 36
San Joaquin Valley Unified Air Pollution Control District June 30, 2011

2010 Air Monitoring Network Plan 

 

iii

The District’s Core Values and the District’s Air Monitoring Network 

* Protect Public Health * 

The District uses data collected from the Valley air monitoring network to generate daily air quality 

forecasts and, when needed, issue health advisories. The District also uses data collected from the 

Valley’s air monitoring network as the basis for long-term attainment strategies and to track progress

towards health-based air quality standards. 

* Active and effective air pollution control efforts with minimal 

disruption to the Valley’s economic prosperity * 

The District uses air monitoring data to help determine what kind of air pollution control efforts are needed 

to achieve health-based air quality standards. 

* Outstanding Customer Service * 

* Accountability to the public * 

The District’s website provides timely and easy public access to data from the Valley’s real-time air 

monitors. The public can also access summaries of the previous seven days of air quality for ozone and 

particulate matter. 

* Open and transparent public processes * 

In addition to making air quality data available in real-time, the District uses air quality data in a variety of 

publicly available documents and reports. The District also conducts a public review period for annual 

monitoring network plans. 

* Respect for the opinions and interest of all Valley residents * 

The District has actively made daily air quality information available to Valley residents in a variety of 

formats, from the District website to the media, and even with air quality flags at schools. The District 

considers public interests in establishing new air monitoring stations. 

* Ingenuity and innovation * 

The District uses new and improved air monitoring techniques as these techniques are approved by the 

EPA. The District uses the latest science when siting air monitors. In turn, data collected from the

monitoring network contributes to ongoing scientific evaluations. 

* Continuous improvement * 

The District evaluates the air monitoring network in the annual Monitoring Network plan for opportunities 

for better data collection and greater efficiency. Furthermore, improved air monitoring is a continuous 

effort; throughout the year, the District seeks out opportunities to improve the air monitoring network. 

* Recognition of the uniqueness of the San Joaquin Valley * 

The San Joaquin Valley is an expansive and diverse area. The District sites air monitors to represent

each type of area and each portion of the region. 

* Effective and efficient use of public funds * 

An air monitoring network requires personnel, instruments, parts, energy, and leases. The District makes 

the most of limited resources by structuring the air monitoring network in a way that optimizes personnel 

time and funding for instruments. The result is a robust air monitoring network that helps the Valley reach 

its air quality goals without unnecessary expenditures.
San Joaquin Valley Unified Air Pollution Control District 

2011 Air Monitoring Network Plan 

Figure 1 Map of Air Monitoring Sites in the San Joaquin Valley 
San Joaquin Valley Unified Air Pollution Control District June 30, 2011

2011 Air Monitoring Network Plan 2

 

Executive Summary 

The San Joaquin Valley Air Pollution Control District (SJVAPCD or District) operates an 

extensive network of air quality monitors throughout the San Joaquin Valley (Valley) to 

support its mission of improving and protecting public health. On a short term scale, 

District staff use the hourly readings from real-time monitors daily to generate an Air 

Quality Index (AQI) for each of the Valley’s eight counties. The AQI is displayed on the 

District website, in Valley media and the Real-time Air Advisory Network (RAAN), and 

as school air quality flags to communicate the current state of air quality to Valley 

residents so they can keep air quality in mind as they plan their activities. The District 

also uses real-time air quality data to manage prescribed burning, agricultural burning, 

and residential wood combustion to ensure these activities do not make air quality 

unhealthy. 

The Valley’s attainment status for the U.S. Environmental Protection Agency’s (EPA) 

health-based air quality standards, the foundation of the District’s air quality attainment 

plans (such as the 2007 Ozone Plan, the 2008 PM2.5 Plan, and upcoming plans), and 

the studies that contribute to these plans are determined by the monitoring data that is 

collected. As part of the District’s long-term efforts to improve public health, air monitors 

collect data that is rigorously analyzed by laboratory technicians and District staff. This 

data is fundamental in the Valley’s effort to achieve improved air quality and attainment 

of EPA’s health-based standards as quickly as possible. 

The San Joaquin Valley covers an area of 23,490 square miles, and the area is home to 

one of the most challenging air quality problems in the nation. The Valley is 

nonattainment for federal PM2.5 and ozone standards, is in attainment of the federal 

standards for lead, Nitrogen dioxide, Sulfur dioxide, and Carbon monoxide. In addition, 

the Valley is an attainment/maintenance area for PM10. The Valley is home to 

approximately 4 million residents, and includes several major metropolitan areas, vast 

expanses of agricultural land, industrial sources, highways, and schools. This 

expansive and diverse area comprises many air quality needs, yet there are limited 

financial and personnel resources for air quality monitoring. 

Despite these limitations and challenges, the District maintains a robust air monitoring 

program. The District follows federal monitoring requirements and guidelines to ensure 

an efficient and effective monitoring network. This monitoring network plan describes 

the District’s approach for implementing federal air monitoring and quality control 

requirements and summarizes recent and upcoming changes to the monitoring network. 

As specified in 40 CFR 58.10(a), this plan is made available for public inspection at 

least 30 days prior to submission to EPA. 
San Joaquin Valley Unified Air Pollution Control District June 30, 2011

2011 Air Monitoring Network Plan 3

 

Introduction: Air Monitoring Network Plan requirements 

Annual monitoring network plans review a region’s existing and proposed monitoring 

network in compliance with 40 CFR (Code of Federal Regulations) 58.10 as well as 

requirements linked to the District’s EPA 105 Grant. The annual monitoring network 

plans are updated and submitted to the EPA Regional Administrator each year, and 

each plan must be made available for public inspection for at least 30 days prior to 

submission to EPA. The plans are to provide for the establishment and maintenance of 

an air monitoring network that may include the following types of stations and 

equipment: 

Abbreviation Full Name Description 

ARM Approved Regional 

Method 

A method that has been approved within a specific 

region for comparison to federal air quality standards. 

There are no ARM monitors in the San Joaquin 

Valley.

FEM Federal Equivalent 

Method 

These monitors are considered to be equivalent to 

FRM monitors for the purpose of determining 

compliance with EPA’s health-based air quality 

standards. 

FRM Federal Reference 

Method 

EPA defines how these monitors are to work, how 

they are to be engineered, and how they are to 

measure pollutants. These monitors are used to 

determine compliance with EPA’s health-based air 

quality standards. 

NCore National Core Multipollutant monitoring stations; in California, these 

are operated by the California Air Resources Board 

(CARB) 

PAMS Photochemical 

Assessment 

Monitoring Station 

VOC (volatile organic compounds) speciation sites 

used in serious, severe, or extreme ozone 

nonattainment areas for precursor evaluation. 

SLAMS State and Local Air 

Monitoring Station 

Monitoring sites that are used for determinations of 

compliance with federal air quality standards, though 

they may be used for other purposes as well 

SPM Special Purpose 

Monitor 

Not included when showing compliance with the 

minimum air monitoring requirements; an example 

might include a temporary monitoring station set up

in an area to measure short term air quality impacts 

of a source. Data collected from an SPM can be 

used for Regulatory purposes if the monitor has been 

operational for two years and if the monitor is an 

ARM, FEM, or FRM. 

STN Speciated Trends 

Network 

PM2.5 speciation stations that provide chemical 

speciation data of PM 
San Joaquin Valley Unified Air Pollution Control District June 30, 2011

2011 Air Monitoring Network Plan 4

 

The monitoring network plan should include a statement of purpose for each monitor 

and evidence that siting and operation of each monitor meets the requirements of 

appendices A, C, D, and E of 40 CFR part 58. The plan must contain the following 

information for each existing and proposed site (40 CFR 58.10 (b)): 

• The MSA, CBSA, CSA, or other area represented by the monitor. MSA, CBSA, 

and CSA are statistical-based definitions for metropolitan areas provided by the 

Office of Management and Budget and the Census Bureau (see Table 1): 

o MSA: Metropolitan statistical area 

o CBSA: Core-based statistical area 

o CSA: Combined statistical area 

• Air quality system (AQS) AIRS Code site identification number (see Table 2) 

• Locations: street address and geographical coordinates 

• Sampling and analysis methods for each measured parameter 

• Operating schedules for each monitor 

• Monitoring objective and spatial scale of representativeness for each monitor (as 

defined in Appendix D to 40 CFR 58) 

• Any proposals to remove or move a monitoring station within 18 months of a plan 

submittal. Any proposed additions and discontinuations of SLAMS monitors are 

subject to approval according to 40 CFR 58.14 

• Each air monitor is sited to satisfy at least one of three specific criteria: 

o Population (see Table 3) 

o Generally consistent pollution concentrations 

o A specific geographic scale 

Table 1 SJV Areas of Representation 

Title Code 

Combined Statistical Area (CSA) CSA Code 

Fresno-Madera CSA 260 

Metropolitan Statistical Area (MSA) Core-based Statistical Area (CSBA) Code 

Bakersfield 112540 

Fresno 23420 

Hanford-Corcoran 25260 

Madera 31460 

Merced 32900 

Modesto 33700 

Stockton 44700 

Visalia - Porterville 47300 
San Joaquin Valley Unified Air Pollution Control District June 30, 2011

2011 Air Monitoring Network Plan 5

 

SJV Areas of Representation 

Title Code 

Counties Federal Information Processing Standard 

(FIPS) Code 

Fresno 06019 

Kern 06029 

Kings 06031 

Madera 06039 

Merced 06047 

Stanislaus 06099 

San Joaquin 06077 

Tulare 06107 

1

 Monitors from both the District and the Kern County Air Pollution Control District can be counted in determining 

compliance with minimum monitoring requirements for the Bakersfield MSA. However, only monitors located within 

the District’s boundaries are included in this network plan. 

Table 2 Site Identification and AQS AIRS Codes 

MSA/CBSA: Fresno 

County: Fresno

Site Name AIRS Code Agency

Clovis–Villa 060195001 SJVAPCD 

Fresno--Drummond 060190007 SJVAPCD 

Fresno–First 060190008 CARB 

Fresno–Pacific 060195025 SJVAPCD 

Fresno–Sky Park 060190242 SJVAPCD 

Huron 060192008 SJVAPCD 

Parlier 060194001 SJVAPCD 

Tranquillity 060192009 SJVAPCD 

MSA/CBSA: Bakersfield 

County: Kern (Valley Portion) 

Site Name AIRS Code Agency

Arvin–Di Giorgio 060295002 CARB 

Bakersfield–California 060290014 Shared 2

Bakersfield–Planz 060290016 CARB 

Edison 060290007 CARB 

Lebec 060292009 SJVAPCD 

Maricopa 060290008 SJVAPCD 

Oildale 060290232 CARB 

Shafter 060296001 Shared 1
San Joaquin Valley Unified Air Pollution Control District June 30, 2011

2011 Air Monitoring Network Plan 6

 

Site Identification and AQS AIRS Codes

MSA/CBSA: Hanford – Corcoran 

County: Kings

Site Name AIRS Code Agency

Corcoran–Patterson 060310004 SJVAPCD 

Hanford--Irwin 060311004 SJVAPCD 

Santa Rosa Rancheria 060310500 Tachi-Yokut Tribe 

MSA/CBSA: Madera 

County: Madera 

Site Name AIRS Code Agency

Madera–City 060392010 SJVAPCD 

Madera–Pump Yard 060390004 SJVAPCD 

MSA/CBSA: Merced 

County: Merced 

Site Name AIRS Code Agency

Merced–Coffee 060470003 SJVAPCD 

Merced–M Street 060472510 SJVAPCD 

MSA/CBSA: Stockton 

County: San Joaquin 

Site Name AIRS Code Agency

Manteca 060772010 SJVAPCD 

Stockton--Hazelton 060771002 CARB 

Stockton–Wagner/Holt 060773010 SJVAPCD 

Tracy–Airport 060773005 SJVAPCD 

MSA/CBSA: Modesto 

County: Stanislaus 

Site Name AIRS Code Agency

Modesto–14th Street 060990005 CARB 

Turlock 060990006 SJVAPCD 

MSA/CBSA: Visalia – Porterville 

County: Tulare 

Site Name AIRS Code Agency

Porterville 061072010 SJVAPCD 

Sequoia–Ash Mountain 061070009 National Park Service 

Sequoia–Lower Kaweah 061070006 National Park Service 

Visalia–Airport 061073000 SJVAPCD 

Visalia–Church 061072002 CARB 

1

 Site operated by CARB and SJVAPCD 

2

 Site operated by CARB and one temporary monitor operated by SJVAPCD. 
San Joaquin Valley Unified Air Pollution Control District June 30, 2011

2011 Air Monitoring Network Plan 7

 

Table 3 San Joaquin Valley 2009 Population 

County Total County 

Population 

Major Urban Area 

Pop > 100,000 

Urban Area Pop 

< 100,000 and > 50,000 

Fresno 942,298 Fresno Clovis 

Kern (Entire County) 827,173 Bakersfield Delano 

Kern (Valley Portion) 686,967 Bakersfield Delano 

Kings 154,743 -- Hanford 

Madera 152,331 -- Madera 

Merced 256,450 -- Merced 

San Joaquin 689,480 Stockton Lodi, Manteca, Tracy 

Stanislaus 526,383 Modesto Turlock 

Tulare 441,481 Visalia Porterville, Tulare 

SJV Total 3,850,133 

Data from California Department of Finance E-4 Population Estimates for Cities, Counties and the State, 

2001-2009, with 2000 Benchmark. Estimates for 1/1/2010 are not yet available. 

There are several network plan requirements that pertain specifically to PM2.5 

monitoring. For example, the monitoring network plan must identify which sites are 

suitable and which are not suitable for comparison against the annual PM2.5 national 

ambient air quality standards (NAAQS) as described in 40 CFR 58.30. The plan must 

also document how agencies provide for public review of changes to the PM2.5 

monitoring network when the change impacts the location of a violating PM2.5 monitor 

or the creation/change to a community monitoring zone. If the District uses spatial 

averaging, a description of the proposed use of spatial averaging for purposes of 

making comparisons to the annual PM2.5 NAAQS as required in Appendix N to part 50 

should be included. Agencies should submit any public comments received from PM2.5 

monitoring changes in the submittal of the network plan. 

Monitoring Objectives and Spatial Scales 

Appendix D to 40 CFR Part 54 identifies three basic monitoring objectives: 

• Provide air pollution data to the general public in a timely manner 

(timely/public) 

• Support compliance with ambient air quality standards and emissions strategy 

development (standards/strategy) 

• Support for air pollution research studies (research support) 

Appendix D then identifies several general monitoring site types to meet the objectives: 

• Sites located to determine the highest concentrations in the area covered 

by the network 

• Population oriented sites to measure typical concentrations in areas of high 

population density 

• Source impact sites to determine the impact of significant sources or source 

categories on air quality 
San Joaquin Valley Unified Air Pollution Control District June 30, 2011

2011 Air Monitoring Network Plan 8

 

• General/background sites determine background concentration levels

• Regional transport sites located to determine the extent of regional pollutant 

transport among populated areas and in support of secondary standards 

• Sites located to measure air pollution impacts on visibility, vegetation 

damage, or other welfare-related impacts 

Appendix D also identifies several scales of spatial representativeness, described in 

terms of physical dimensions of the air parcel or zone where air quality is expected to 

be reasonably consistent around the monitor. The monitor thus represents that area, 

not just the point of the monitor. The spatial scales are: 

• Microscale: an area ranging from several meters up to about 100 meters 

• Middle scale: an area covering between about 100 meters to 0.5 kilometers 

• Neighborhood scale: covering an area between 0.5 and 4.0 kilometers in 

range 

• Urban scale: covering an area of city-like dimensions, from about 4 to 50 

kilometers 

• Regional scale: covering a rural area of reasonably homogeneous 

geography without large sources, extending from tens to hundreds of 

kilometers 

• National and global scales: representing concentrations characterizing the 

nation and the globe as a whole 

New monitoring stations and new monitors must meet EPA siting criteria. A particular 

site might be appropriate for one or more pollutants. Some sites might be appropriate 

for all air pollutant monitoring, while other sites might only be appropriate for a particular 

pollutant. The District balances a wide range of pollutant siting criteria, spatial scales, 

monitoring objectives, and practical concerns as it plans and operates its monitoring 

network. Table 4 summarizes all the ambient air monitoring sites in the San Joaquin 

Valley Air Basin. 
San Joaquin Valley Unified Air Pollution Control District 

2011 Air Monitoring Network Plan 

Table 4 Ambient Air Monitoring Sites in the San Joaquin Valley Air Basin (Summ

As of June 1, 2011 

MSA, County Site Name Address Parameters Monito

Clovis-Villa 908 N. Villa Ave., Clovis, CA 93612 

Ozone, PM10 FRM, PM2.5 BAM/FEMNMOC (PAMS), wind speed, wind dirtemperature, relative humidity, baromradiation 

 Fresno-Drummond 4706 E. Drummond St., Fresno, CA 93725 Ozone, PM10 FRM, CO, NO2, wind s

outdoor temperature, barometric pres

 Fresno-First 3425 N. First St, Fresno CA 93726 

Ozone, PM10 FRM, PM10 BAM, PMBAM, CO, NO2, SO2, toxics, wind spoutdoor temperature, relative humiditpressure 

Fresno, 

Fresno Fresno-Pacific 1716 Winery, Fresno, CA 93726 PM2.5 FRM 

 Fresno-Sky Park 4508 Chennault Ave, Fresno, CA 93722 Ozone, CO, NO2, wind speed, wind d

temperature 

 Huron 16875 4th St., Huron, CA 93234 PM2.5 BAM, barometric pressure  Parlier 

9240 S. Riverbend Ave., Parlier, CA 93648 

Ozone, NO2, NMOC (PAMS), NMHCdirection, outdoor temperature, relativbarometric pressure, solar radiation 

 Tranquillity 32650 W. Adams, Tranquillity, CA 93668 Ozone, PM2.5 BAM FEM, wind spee

outdoor temperature, barometric pres
San Joaquin Valley Unified Air Pollution Control District 

2011 Air Monitoring Network Plan 

MSA, County Site Name Address Parameters Monito

Arvin-Di Giorgio 19405 Buena Vista Blvd, Arvin, CA 93203 Ozone, outdoor temperature 

 Bakersfield-Planz 401 E. Planz Rd., Bakersfield CA 93307 PM2.5 FRM  Bakersfield-California 5558 California Ave., Bakersfield, CA 93309 

Ozone, PM10 FRM, PM10 BAM/FEM operated by the SJVAPCD), PM2.5 FBAM/FEM, NO2, toxics, Cr6+, wind spoutdoor temperature, relative humiditpressure, solar radiation 

Bakersfield, 

Kern Edison Johnson Farm-Shed Rd, Edison, CA 93320 Ozone, NO2, wind speed, wind direct

temperature 

 Lebec Beartrap Road (no #), Lebec, CA 91350 PM2.5 BAM, wind speed, wind direct

temperature, relative humidity, barom

radiation 

 Maricopa 755 Stanislaus St., Maricopa, CA 93352 Ozone, wind speed, wind direction, o

barometric pressure 

 Oildale 3311 Manor St, Oildale, CA 93308 Ozone, PM10 FRM, wind speed, wind 

temperature 

 Shafter 578 Walker St, Shafter, CA 93263 Ozone, NO2, NMOC (PAMS), NMHC

direction, outdoor temperature, relativbarometric pressure, solar radiation 

Corcoran-Patterson 1520 Patterson Ave, Corcoran, CA 93212 PM10 FRM, PM10 TEOM, PM2.5 FR

wind speed, wind direction, outdoor tbarometric pressure 

Hanford – Corcoran, 

Kings 

Hanford-Irwin 807 S. Irwin St, Hanford, CA 93230 Ozone, PM10 FRM, PM2.5 BAM/FEM

wind direction, outdoor temperature, 

 Santa Rosa Rancheria 17225 Jersey Ave., Lemoore, CA 93245 Ozone, PM10, meteorology 
San Joaquin Valley Unified Air Pollution Control District 

2011 Air Monitoring Network Plan 

MSA, County Site Name Address Parameters Monito

Madera-City 28261 Avenue 14, Madera, CA 93638 Ozone, PM10 TEOM, PM2.5 BAM/FE

direction, outdoor temperature, barom

Madera, relative humidity, solar radiation 

Madera 

Madera-Pump Yard Av 8 and Road 29 1/2, Madera, CA 93637 Ozone, NO2, NMOC (PAMS), NMHC

direction, outdoor temperature, relativbarometric pressure, solar radiation 

Merced-Coffee 385 S. Coffee St., Merced, CA 95340 Ozone, PM2.5 BAM/FEM, NO2, wind 

direction, outdoor temperature, barom

Merced, 

Merced Merced-M Street 2334 M Street, Merced, CA 95340 PM10 FRM, PM2.5 FRM 

Stockton-Hazelton 1593 E. Hazelton St., Stockton, CA 95205 Ozone, PM10 FRM, PM2.5 FRM, PM

toxics, wind speed, wind direction, ou

relative humidity 

Stockton-Wagner/Holt 8778 Brattle Pl., Stockton, CA 95209 PM10 FRM Manteca 530 Fishback Rd., Manteca, CA 95337 PM2.5 BAM/FEM, PM10 (TEOM), wi

direction, outdoor temperature, barom

Stockton, 

San Joaquin 

Tracy-Airport 5749 S. Tracy Blvd., Tracy, CA 95376 Ozone, PM10 TEOM, PM2.5 BAM, N

direction, outdoor temperature, baromacoustic sounding system (RASS) 

Modesto-14th Street 814 14th Street, Modesto, CA 95354 Ozone, PM10 FRM, PM2.5 FRM, PM

speed, wind direction, outdoor tempe

Modesto, pressure 

Stanislaus 

Turlock 1034 S. Minaret St., Turlock, CA 95380 Ozone, PM10 FRM, PM2.5 BAM FEM

speed, wind direction, outdoor tempepressure 
San Joaquin Valley Unified Air Pollution Control District 

2011 Air Monitoring Network Plan 

MSA, County Site Name Address Parameters Monito

Porterville 1839 S. Newcomb St., Porterville, CA 93257 Ozone, PM2.5 BAM, wind speed, win

temperature, barometric pressure 

Sequoia-Ash Mountain 

Ash Mountain, Sequoia National Park CA 

Ozone, PM2.5 FRM, PM2.5 BAM, widirection, outdoor temperature, relativradiation 

Sequoia-Lower Kaweah 

Lower Kaweah Campground, Sequoia National Park, CA 

Ozone, wind speed, wind direction, orelative humidity, solar radiation 

Visalia-Airport Airport, Visalia, CA 93291 wind speed, wind direction, outdoor t

humidity, barometric pressure, solar r

acoustic sounding system (RASS) 

Visalia – 

Porterville, 

Tulare 

Visalia-Church 310 N. Church St., Visalia, CA 93291 Ozone, PM10 FRM, PM2.5 FRM, PM

speed, wind direction, outdoor tempe

pressure 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 13

 

Ozone 

Ozone is formed when its precursors (oxides of nitrogen (NOx) and volatile organic 

compounds (VOC)) chemically react in the presence of sunlight. The Valley’s 

topography, low precipitation levels, high temperatures, subsidence inversions, and light 

winds are conducive to elevated ozone levels. Winds (at ground level or at higher 

altitudes) transport pollutants from other basins into the Valley, within the Valley to 

areas downwind, and from the Valley into other regions. 

As shown in Table 5, the Valley’s ozone network meets the monitoring requirements as 

listed in Table D-2 of Appendix D to Part 58. Ozone monitoring site requirements are 

based on MSA population (see Table 3) and design values (see Table 6). Sites are 

intended to represent population exposures and maximum concentrations so most 

ozone monitors are representative of neighborhood and regional scales (see Table 7). 

The Valley’s SLAMS ozone monitors are continuous analyzers that detect ozone 

through ultraviolet absorption. As continuous devices, these monitors meet the 

“Timely/Public” objective, providing District staff with the data used in AQI forecasting 

and reporting. The Valley’s ozone monitoring sites are shown in Table 7. 

Table 5 SLAMS Minimum Ozone Monitoring Requirements 

(Table D-2 of Appendix D to Part 58) 

Number of monitors required if: 

MSA population, based 

on latest available 

census figures 

Most recent 3-year design 

value concentrations ≥85% of 

any ozone NAAQS 

Most recent 3-year design 

value concentrations <85% of 

any ozone NAAQS 

> 10 million 4 2 

4 – 10 million 3 1 

350,000 – < 4 million 2 1 

50,000 – < 350,000 1 0 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 14

 

Table 6 Ozone Requirements for the San Joaquin Valley 

Metropolitan 

Statistical Area 

(MSA) 

2009 

Population 

Highest 

2006-2008 

Ozone 

Design 

Value in 

MSA (ppb)1 

≥85% of 

2008 ozone 

NAAQS (75 

ppb)1

Number of 

monitors 

required 

(Table 5) 

Number of 

active 

SLAMS 

ozone 

monitor 

sites 

Bakersfield 827,173 2 105 Yes 2 6 2 

Fresno 942,298 100 Yes 2 6 

HanfordCorcoran 154,743 91 Yes 1 1

Madera 152,331 84 Yes 1 2 

Merced 256,450 90 Yes 1 1 

Modesto 526,383 89 Yes 2 2 

Stockton 689,480 83 Yes 2 2 

Visalia - 

Porterville 441,481 103 Yes 2 2 

1 These data are preliminary. Air quality data may include data influenced by exceptional events 

 and/or data completeness and substitution requirements. 

2

 The population listed for Bakersfield here reflects the population for all of Kern County, not just 

 the Valley portion. Air monitors in the Eastern Kern Air District would count towards the monitors 

 required for the Bakersfield MSA. However, the “Number of active ozone monitors” listed here 

 includes those in the San Joaquin Valley Air Basin only. 

Table 7a San Joaquin Valley Ozone Monitors (SLAMS)

As of June 1, 2011

MSA County Site Scale Site Type Monitoring 

Objective 

Clovis–Villa Neighborhood Population 

Fresno– 

Drummond Neighborhood Population, Regional transport 

Fresno– 

First Neighborhood Population 

Fresno-- Sky 

Park Neighborhood Population, Regional transport 

Fresno Fresno 

Parlier Neighborhood High Concentration, 

Regional transport 

1, 2, 3 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 15

 

San Joaquin Valley Ozone Monitors (SLAMS) 

MSA County Site Scale Site Type Monitoring 

Objective 

Arvin-Di 

Giorgio Neighborhood High Concentration, Regional transport 

BakersfieldCalifornia Neighborhood Population 

Edison Neighborhood High concentration, 

Regional transport 

Maricopa Neighborhood Regional transport 

Oildale Neighborhood Regional transport 

Bakersfield Kern 

Shafter Neighborhood General/background 

1, 2, 3 

 

MSA County Site Scale Site Type Monitoring 

Objective 

HanfordCorcoran Kings HanfordIrwin 1 Neighborhood Population 1, 2, 3 

 

MSA County Site Scale Site Type Monitoring 

Objective 

Madera– 

Pump Yard Neighborhood General/background Madera Madera 

Madera- City Neighborhood Population 

1, 2, 3 

 

MSA County Site Scale Site Type Monitoring 

Objective 

Merced Merced Merced– 

Coffee Neighborhood Population 1, 2, 3 

 

MSA County Site Scale Site Type Monitoring 

Objective 

Stockton– 

Hazelton Neighborhood Population 

Stockton San 

Joaquin Tracy-- 

Airport Neighborhood Regional transport 

1, 2, 3 

MSA County Site Scale Site Type Monitoring 

Objective 

Modesto– 

14th Street Neighborhood Population 

Modesto Stanislaus 

Turlock Neighborhood Population 

1, 2, 3 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 16

 

San Joaquin Valley Ozone Monitors (SLAMS)

MSA County Site Scale Site Type Monitoring 

Objective 

Visalia– 

Church Visalia - Neighborhood Population 

Porterville Tulare 

Porterville Neighborhood Population 

1, 2, 3 

1 – Standards/Strategy 2 – Research Support 3 – Timely/Public 

1

Shutdown of the Corcoran-Patterson ozone monitor occurred in November 2009. The monitor was 

 reinstalled at the reconstructed Hanford-Irwin monitoring site in February 2010. During the months 

 in between, the monitor was serviced, calibrated and tested. 

Table 7b San Joaquin Valley Ozone Monitors (SPM) 

As of June 1, 2011

MSA County Site Scale Site Type Monitoring 

Objective 

Fresno Fresno Tranquillity 1 Urban 

Scale Population 3 

HanfordCorcoran Kings Santa Rosa Rancheria 2

Tribal monitor 

Sequoia -Ash Mountain 1 Regional Regional 

transport 3 Visalia - 

Porterville Tulare 

Sequoia -Lower Kaweah 1 Regional Regional 

transport 3 

3 – Research Support Timely/Public 

1

These SPMs can be used for Regulatory purposes. 

2

The status of this Tribal monitor is not known. 

 

PAMS 

The monitoring objective of Photochemical Assessment Monitoring Stations is research 

support. Federal regulations (Clean Air Act Section 182 and 40 CFR 58) require 

serious, severe, and extreme ozone nonattainment areas to have PAMS sites to take 

speciated measurements of ozone precursors and allow for better understanding of the 

effect of precursors, control measures, and photochemistry on ozone formation. PAMS 

sites measure ozone, NOx, speciated VOC (NMOC and NMHC), CO, and meteorology 

concurrently. 

There are four classifications of PAMS sites: 

• Type 1: Background sites upwind of urban areas, where ozone concentrations 

 are presumed not to be influenced by nearby urban emissions 

• Type 2: Maximum ozone precursor emissions sites, typically located in an urban 

 center, where emissions strengths are the greatest 

• Type 3: Maximum ozone concentration sites, intended to show the highest 

 ozone concentrations 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 17

 

• Type 4: Extreme downwind monitoring sites, which are expected to capture 

 concentrations of transported pollutants but have lower ozone 

 concentrations due to a lack of more local emissions sources (currently not 

 required for the SJV) 

As shown in Table 8, the District has a total of six PAMS sites configured as two small 

networks, one centered around Fresno and one around Bakersfield. The PAMS 

program operates from June 1 through August 31 every year on a 1 in 3 day sampling 

schedule. At least four, three-hour integrated samples are collected each sampling day, 

referred to as a “Trend Day.” However, additional samples are collected on “Episode 

Days,” days that are forecasted to have high ozone concentrations. The goal is to 

sample on three to five multi-day episodes in an ozone season. 

Table 8 SJV PAMS sites 

As of June 1, 2011 

Type 1: Upwind/Background site Madera-Pump Yard 

Fresno MSA Type 2: Maximum precursor emissions Clovis-Villa 

Type 3: Maximum ozone concentrations Parlier 

Type 1: Upwind/Background site Shafter 

Type 2: Maximum precursor emissions Replacement site under 

construction Bakersfield MSA 1 

Type 3: Maximum ozone concentrations Arvin2

1 Bakersfield–Golden was shut down for relocation in December 2009. The District plans to have the replacement 

 site, Bakersfield-Muni, operational in October 2011. 

 Bakersfield-Muni, will begin reporting data in October 2011. See page 39 for more information. 

2 Arvin-Bear Mountain Blvd. site closed. CARB plans to construct the Arvin-Di Giorgio site for PAMS 

 and is finalizing details before the project begins. 

Particulate Matter (PM) 

Particulate matter (PM) can be emitted directly as primary PM, and it can form in the 

atmosphere through chemical reactions of precursors to form secondary PM. Primary 

PM can be emitted either naturally (windblown dust and wildfires) or from human 

(anthropogenic) activity: agricultural operations, industrial processes, combustion of 

wood and fossil fuels, construction and demolition activities, and entrainment of road 

dust. The resulting ambient PM mixture includes aerosols consisting of components of 

nitrates, sulfates, elemental Carbons, organic Carbon compounds, acid aerosols, trace 

metals, geological materials, etc. Under current regulations, particulate matter (PM) is 

differentiated by particle size as opposed to composition. Federal air quality standards 

differentiate two size fractions of PM: PM that is 10 microns or less in diameter (PM10) 

and the smaller subset that is 2.5 microns or less in diameter (PM2.5). 

The Valley’s comprehensive particulate field study is the California Regional Particulate 

Air Quality Study (CRPAQS). CRPAQS monitoring occurred between December 1999 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 18

 

and February 2001 through the use of over 70 SPM PM10 sites and 50 SPM PM2.5 

sites. Researchers have used CRPAQS measurements for database development, 

analysis, and modeling. A final report synthesizing all CRPAQS analysis and updating 

the conceptual understanding of particulates is expected to be completed in 2012. In 

addition to CRPAQS, other studies assess particulate emissions from agricultural 

operations, unpaved and paved road particulate emissions, and particulate formation in 

fog episodes. The design of the Valley’s current PM network is an outgrowth of the 

results and analysis from CRPAQS. 

The Valley’s surrounding mountain ranges contribute to PM retention. Over the 

summer, long periods with little or no rainfall result in extreme drying of soils, increasing 

emissions from traffic movement and mechanical disturbance. Winter brings rainfall, 

but also creates an atmospheric environment that forms more secondary particulates. 

The Valley’s frequent and severe temperature inversions block the normal rising air and 

trap particulates close to the ground, especially during the winter months. 

The Valley’s PM monitoring network includes Federal Reference Method (FRM) 

monitors, Federal Equivalent Method (FEM) monitors, and Non-FRM/FEM monitors. 

FRM monitors for PM are manual filter-based monitors; samples are collected on either 

a one-in-six day sampling schedule or a one-in-three day sampling schedule. FRM 

monitors meet the “Standards/Strategy” objective, helping agencies determine the 

Valley’s attainment status and helping shape the strategies for reaching or maintaining 

PM attainment. FRM filters can also be analyzed for PM speciation, so they are 

sometimes used for “Research Support” objectives as well. 

Beta Attenuation Monitors (BAM) and Tapered Element Oscillating Microbalance 

(TEOM) monitors are continuous, near real-time monitors that provide the hourly PM 

data used in AQI and Smoke Management System (SMS) burn allocations. Data from 

these monitors are also used in hazard reduction burning allocations and in residential 

wood burning declarations. As such, these monitors help meet the “Timely/Public” 

objective. 

Not all real-time monitors meet the “Standards/Strategy” objective because they do not 

meet the rigorous engineering design, quality assurance, and quality control standards 

necessary for comparison to the NAAQS. An FEM monitor is often a real-time monitor 

that has been designated by EPA as being equivalent to FRM monitors. FEMs satisfy 

both the “Standards/Strategy” objective and the “Timely/Public” objective. All of the 

Valley’s TEOMs are FEMs, and some of the Valley’s BAMs are FEMs. 

PM10 Monitors in the Valley 

The San Joaquin Valley has been redesignated to attainment for PM10, and the 

District’s 2007 PM10 Maintenance Plan and ongoing PM10 monitoring will assure 

continued compliance with federal standards. The minimum number of PM10 sites 

required per MSA is shown in Table 9 and the PM10 monitoring requirements for the 

San Joaquin Valley are shown in Table 10. Tables 11a, 11b, and 12 summarize the 

Valley’s SLAMS and SPM PM10 monitoring stations, respectively. 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 19

 

Table 9 Minimum PM10 Monitoring Requirements 

(Table D-4 of Appendix D to Part 58) 

(A range is presented, and the actual number of stations per area is jointly determined by 

EPA, the State, and the local agency)

Population category 

High concentration: 

Ambient 

concentrations 

exceed the PM10 

NAAQS by 20% or 

more (≥180 μg/m3)

Medium concentration:

Ambient concentrations 

exceed 80% of the PM10 

NAAQS (>120 μg/m3)

Low concentration: 

Ambient 

concentrations less 

than 80% of the PM10 

NAAQS (< 120 μg/m3), 

or no design value

> 1,000,000 6 – 10 4 – 8 2 – 4 

500,000 – 1,000,000 4 – 8 2 – 4 1 – 2 

250,000 – 500,000 3 – 4 1 – 2 0 – 1 

100,000 – 250,000 1 – 2 0 – 1 0 

Table 10 PM10 Monitoring requirements for the Valley 

PM10 

Metropolitan 

Statistical 

Area (MSA) 

County 2009 

Population 

24-hour 2009 

Highest 

concentration in 

MSA (μg/m3) 2

Monitors 

required 3

Actual 

# of 

SLAMS 

sites in 

MSA 

Actual 

# of 

SPM 

sites in 

MSA 

Bakersfield Kern 827,173 1 138 2 – 4 2 4 

Fresno Fresno 942,298 84 1 – 2 3 1 

HanfordCorcoran Kings 154,743 118 0 – 1 2 2 

Madera Madera 152,331 - 1 1 1 

Merced Merced 256,450 64 0 – 1 1 1 

Modesto Stanislaus 526,383 65 1 – 2 2 

Stockton 

San 

Joaquin 689,480 61 1 – 2 2 1 

Visalia - 

Porterville Tulare 441,481 92 0 - 1 1 

 1The population listed for Bakersfield here reflects the population for all of Kern County, not just the Valley portion. 

 Air monitors in the Eastern Kern Air District would count towards the monitors required for the Bakersfield MSA. 

 However, the “Actual # of monitors in MSA” listed here includes those in the San Joaquin Valley Air Basin only. 

 2 Max PM10 Data does not include any pending Exceptional Events. 

 3 PM10 data does not include collocated monitors. 

 4 One temporary PM10 monitor. 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 20

 

Table 11a San Joaquin Valley PM10 SLAMS monitor information 

MSA/CBSA: Fresno

County: Fresno

Site Name Scale Site Type Monitoring 

Objective 

Sampling 

Schedule 

FresnoDrummond Neighborhood Population Standards/Strategy 

Research Support 1:6 

Standards/Strategy 

Research Support 1:6 

Fresno-First Neighborhood High 

Concentration Research Support 

Timely/Public 1-Hour 

Clovis-Villa Neighborhood Population Standards/Strategy 

Research Support 1:6 

MSA/CBSA: Bakersfield

County: Kern

Site Name Scale Site Type Monitoring 

Objective 

Sampling 

Schedule 

Oildale Neighborhood Population Standards/Strategy 

Research Support 1:6 

Bakersfield- 1:6 

California Neighborhood Population Standards/Strategy Research Support 1-Hour 1

MSA/CBSA: Hanford – Corcoran

County: Kings 

Site Name Scale Site Type Monitoring 

Objective 

Sampling 

Schedule 

Hanford-Irwin Neighborhood Population Standards/Strategy 

Research Support 1:6 

Standards/Strategy 

Research Support 1:3 CorcoranPatterson Neighborhood High 

Concentration Research Support 

Timely/Public 1-Hour 

MSA/CBSA: Madera

County: Madera

Site Name Scale Site Type Monitoring 

Objective 

Sampling 

Schedule 

Madera-City Neighborhood Population Research Support 

Timely/Public 1-Hour 

MSA/CBSA: Merced

County: Merced 

Site Name Scale Site Type Monitoring 

Objective 

Sampling 

Schedule 

Merced-M Street Neighborhood Representative 

concentration 

Standards/Strategy 

Research Support 1:6 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 21

 

San Joaquin Valley PM10 SLAMS monitor information

MSA/CBSA: Stockton

County: San Joaquin

Site Name Scale Site Type Monitoring 

Objective 

Sampling 

Schedule 

Manteca Neighborhood Population Standards/Strategy 

Research Support 1-Hour 

StocktonHazelton Neighborhood Population Standards/Strategy 

Research Support 1:6 

Stockton-Wagner/ 

Holt Neighborhood Population Standards/Strategy Research Support 1:6 

Tracy-Airport Neighborhood Regional 

transport 

Research Support 

Timely/Public 1-Hour 

MSA/CBSA: Modesto

County: Stanislaus

Site Name Scale Site Type Monitoring 

Objective 

Sampling 

Schedule 

Modesto-14th

Street Neighborhood Population Standards/Strategy Research Support 1:6 

Turlock Neighborhood Population Standards/Strategy 

Research Support 1:6 

MSA/CBSA: Visalia – Porterville

County: Tulare

Site Name Scale Site Type Monitoring 

Objective 

Sampling 

Schedule 

Visalia-Church Neighborhood Population Standards/Strategy 

Research Support 1:6 

1

Temporary monitor 

Table 11b San Joaquin Valley PM10 SPM monitor information 

MSA/CBSA: Hanford – Corcoran

County: Kings 

Site Name Scale Site Type Monitoring 

Objective 

Sampling 

Schedule 

Hanford-Irwin 1 Neighborhood Population Research Support 

Timely/Public 1-Hour 

1

This is a new SPM site. Data can be used for Regulatory purposes after the site has been operational for two 

 years.
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 22

 

Table 12 San Joaquin Valley PM10 monitor types 

MSA/CBSA: Fresno Instrument Type Monitor Type 

County: Fresno FRM FEM SLAMS SPM 

Site Name 

Clovis-Villa 1 1 

Fresno-Drummond 1 1 

1 1 Fresno-First 

 1 1 

Total SLAMS/SPM 3 1 

MSA/CBSA: Bakersfield Instrument Type Monitor Type 

County: Kern FRM FEM SLAMS SPM 

Site Name 

1 1 Bakersfield-California 

1

1

 1 

Oildale 1 1 

Total SLAMS/SPM 2 1 

MSA/CBSA: Hanford – Corcoran Instrument Type Monitor Type 

County: Kings FRM FEM SLAMS SPM 

Site Name 

 1 2 1 Corcoran-Patterson 

 1 1 

1 1 Hanford-Irwin 

 1 1 

Santa Rosa Rancheria 3 Tribal Monitor 

Total SLAMS/SPM 2 2 

MSA/CBSA: Madera Instrument Type Monitor Type 

County: Madera FRM FEM SLAMS SPM 

Site Name 

Madera-City 1 1 

Total SLAMS/SPM 1 

MSA/CBSA: Merced Instrument Type Monitor Type 

County: Merced FRM FEM SLAMS SPM 

Site Name 

Merced-M Street 1 1 

Total SLAMS/SPM 1 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 23

 

San Joaquin Valley PM10 monitor types

MSA/CBSA: Stockton Instrument Type Monitor Type 

County: San Joaquin FRM FEM SLAMS SPM 

Site Name 

Manteca 1 1 

Stockton-Hazelton 1 1 

Stockton-Wagner/Holt 1 1 

Tracy-Airport 1 1 

Total SLAMS/SPM 2 2 

MSA/CBSA: Modesto Instrument Type Monitor Type 

County: Stanislaus FRM FEM SLAMS SPM 

Site Name 

Modesto-14th Street 1 1 

Turlock 1 1 

Total SLAMS/SPM 2 

MSA/CBSA: Visalia – Porterville Instrument Type Monitor Type 

County: Tulare FRM FEM SLAMS SPM 

Site Name 

Visalia-Church 1 1 

Total SLAMS/SPM 1 

 1Temporary monitor 

2 QA Collocated monitors 3 Status of this Tribal monitor is not known.

PM2.5 Monitors in the Valley 

The San Joaquin Valley is designated nonattainment for PM2.5. Table 13 shows the 

minimum number of PM2.5 sites required per MSA. The minimum number of PM2.5 

sites required per MSA is shown in Table 13 and the PM2.5 monitoring requirements for 

the San Joaquin Valley are shown in Table 14. Tables 15a, 15b, and 16 summarize the 

Valley’s SLAMS and SPM PM2.5 monitoring stations, respectively. 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 24

 

Table 13 Minimum PM2.5 Monitoring Requirements 

MSA population 

Most recent 3-year design 

value ≥85% of any PM2.5 

NAAQS (equivalent to an annual 

design value ≥ 12.8 μg/m3 or a 

24-hour design value ≥ 29.8 

μg/m3) 

Most recent 3-year design 

value <85% of any PM2.5 

NAAQS (equivalent to an annual 

design value < 12.8 μg/m3 or a 

24-hour design value < 29.8 

μg/m3), or no design value 

> 1,000,000 3 2 

500,000 – 1,000,000 2 1 

50,000 - < 500,000 1 0 

Table 14 PM2.5 Monitoring requirements for the Valley 

PM2.5 

Metropolitan 

Statistical 

Area (MSA) 

County 2009 

Population

24-hour 

2007-

2009 

Design 

Value in 

MSA 

(μg/m3) 2

Annual 

2007-

2009 

Design 

Value in 

MSA 

(μg/m3) 

Monitors 

required 

Actual # 

of 

SLAMS 

sites in 

MSA 

Actual 

# of 

SPM 

sites 

in 

MSA 

Bakersfield Kern 827,1731 70 22.6 2 2 2 

Fresno Fresno 942,298 60 17.1 2 3 3 

HanfordCorcoran Kings 154,743 53 17.3 1 1 1 

Madera Madera 152,331 - - 1 1 

Merced Merced 256,450 51 14.5 1 1 1 

Modesto Stanislaus 526,383 60 23.2 2 2 

Stockton 

San 

Joaquin 689,480 50 12.9 2 2 1 

VisaliaPorterville Tulare 441,481 59 18.8 1 1 3 

 1 The population listed for Bakersfield here reflects the population for all of Kern County, not just the Valley 

 portion. Air monitors in the Eastern Kern Air District would count towards the monitors required for the 

 Bakersfield MSA. However, the “Actual # of monitors in MSA” listed here includes those in the San Joaquin 

 Valley Air Basin only. 

 2 These data are preliminary. Air quality data may include data influenced by exceptional events and/or data 

 completeness and substitution requirements.
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 25

 

Table 15a San Joaquin Valley PM2.5 SLAMS monitor information 

MSA/CBSA: Fresno

County: Fresno

Site Name Scale Site Type Monitoring Objective Sampling 

Schedule 

FresnoPacific Neighborhood Population Standards/Strategy 

Research Support Seasonal 

Research Support 

Timely/Public 1-Hour 

Fresno-First Neighborhood High 

Concentration Standards/Strategy 

Research Support Daily 

Clovis-Villa Neighborhood Population Research Support 

Timely/Public 1-Hour 

MSA/CBSA: Bakersfield

County: Kern

Site Name Scale Site Type Monitoring Objective Sampling 

Schedule 

Research Support 

Timely/Public Bakersfield- 1-Hour 

California Neighborhood Population 

Standards/Strategy Daily 

BakersfieldPlanz Neighborhood Population Standards/Strategy 1:3 

MSA/CBSA: Hanford – Corcoran

County: Kings

Site Name Scale Site Type Monitoring Objective Sampling 

Schedule 

Standards/Strategy 

Research Support Seasonal CorcoranPatterson Neighborhood High 

Concentration Research Support 

Timely/Public 1-Hour 

MSA/CBSA: Merced

County: Merced

Site Name Scale Site Type Monitoring Objective Sampling 

Schedule 

Merced-M 

Street Neighborhood Representative concentration 

Standards/Strategy 

Research Support 1:3 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 26

 

San Joaquin Valley PM2.5 SLAMS monitor information

MSA/CBSA: Stockton

County: San Joaquin

Site Name Scale Site Type Monitoring Objective Sampling 

Schedule 

Manteca Neighborhood Population Standards/Strategy 

Research Support 1-Hour 

Standards/Strategy 

Research Support 1:3 / 1-Hour 1 Stockton– 

Hazelton Neighborhood Population 

Research Support 

Timely/Public 1-Hour 

MSA/CBSA: Modesto

County: Stanislaus

Site Name Scale Site Type Monitoring Objective Sampling 

Schedule 

Standards/Strategy 

Research Support 1:3 / 1-Hour 1Modesto– 

14th Street Neighborhood Population Research Support 

Timely/Public 1-Hour 

Turlock Neighborhood Population Research Support 

Timely/Public 1-Hour 

MSA/CBSA: Visalia – Porterville 

County: Tulare 

Site Name Scale Site Type Monitoring Objective Sampling 

Schedule 

Standards/Strategy 

Research Support 1:3 Visalia– 

Church Neighborhood Population Research Support 

Timely/Public 1-Hour 

1 An FRM was replaced with an FEM 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 27

 

Table 15b San Joaquin Valley PM2.5 SPM monitor information 

MSA/CBSA: Fresno

County: Fresno

Site Name Scale Site Type Monitoring Objective Sampling 

Schedule 

Huron Neighborhood Population Research Support 

Timely/Public 1-Hour 

Tranquillity Urban Urban Research Support 

Timely/Public 1-Hour 

MSA/CBSA: Bakersfield

County: Kern

Site Name Scale Site Type Monitoring Objective Sampling 

Schedule 

Lebec Neighborhood Population Research Support 

Timely/Public 1-Hour 

MSA/CBSA: Hanford – Corcoran

County: Kings

Site Name Scale Site Type Monitoring Objective Sampling 

Schedule 

Hanford-Irwin Neighborhood Population Research Support 

Timely/Public 1-Hour 

MSA/CBSA: Madera

County: Madera

Site Name Scale Site Type Monitoring Objective Sampling 

Schedule 

Madera-City Neighborhood Population Research Support 

Timely/Public 1-Hour 

MSA/CBSA: Merced

County: Merced

Site Name Scale Site Type Monitoring Objective Sampling 

Schedule 

MercedCoffee Neighborhood Population Research Support 

Timely/Public 1-Hour 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 28

 

San Joaquin Valley PM2.5 SPM monitor information

MSA/CBSA: Stockton

County: San Joaquin

Site Name Scale Site Type Monitoring Objective Sampling 

Schedule 

Tracy-Airport Neighborhood Regional 

transport 

Research Support 

Timely/Public 1-Hour 

MSA/CBSA: Visalia – Porterville

County: Tulare

Site Name Scale Site Type Monitoring Objective Sampling 

Schedule 

Sequoia-Ash 

Mountain Regional Regional transport 

Research Support 

Timely/Public 1-Hour 

Porterville Neighborhood Population Research Support 

Timely/Public 1-Hour 

Table 16 San Joaquin Valley PM2.5 monitor types 

MSA/CBSA: Fresno Instrument Type Monitor Type 

County: Fresno FRM FEM Non-FEM SLAMS SPM 

Site Name 

Clovis-Villa 1 1 

1 1 Fresno-First 1 1 

Fresno-Pacific 1 1 

Huron 1 1 

Tranquillity 1 1 

Total SLAMS/SPM 3 3 

MSA/CBSA: Bakersfield Instrument Type Monitor Type 

County: Kern FRM FEM Non-FEM SLAMS SPM 

Site Name 

Bakersfield-Planz 1 1 

1 1 Bakersfield-California 

 1 1 

Lebec 1 1 

Total SLAMS/SPM 2 1 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 29

 

San Joaquin Valley PM2.5 monitor types

MSA/CBSA: Hanford – Corcoran Instrument Type Monitor Type 

County: Kings FRM FEM Non-FEM SLAMS SPM 

Site Name 

1 Corcoran-Patterson 1 1 

Hanford-Irwin 1 1 

Total SLAMS/SPM 1 1 

MSA/CBSA: Madera Instrument Type Monitor Type 

County: Madera FRM FEM Non-FEM SLAMS SPM 

Site Name 

Madera-City 1 1 

Total SLAMS/SPM 1 

MSA/CBSA: Merced Instrument Type Monitor Type 

County: Merced FRM FEM Non-FEM SLAMS SPM 

Site Name 

Merced-Coffee 1 1 

Merced-M Street 1 1 

Total SLAMS/SPM 1 1 

MSA/CBSA: Instrument Type Monitor Type Stockton

County: San Joaquin FRM FEM Non-FEM SLAMS SPM 

Site Name 

Manteca 1 1 

Stockton-Hazelton 1 1 1 

Tracy-Airport 1 1 

Total SLAMS/SPM 2 1 

MSA/CBSA: Modesto Instrument Type Monitor Type 

County: Stanislaus FRM FEM Non-FEM SLAMS SPM 

Site Name 

Modesto-14th Street 1 1 1 

Turlock 1 1 

Total SLAMS/SPM 2 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 30

 

San Joaquin Valley PM2.5 monitor types

MSA/CBSA: Visalia – Porterville Instrument Type Monitor Type 

County: Tulare FRM FEM Non-FEM SLAMS SPM 

Site Name 

Porterville 2 1 1 

Sequoia-Ash Mountain 1 1 

1 1 Visalia-Church 1 1 

Total SLAMS/SPM 1 3 

 1 An FRM was replaced with an FEM.

 2 Data can be used for Regulatory purposes after the site has been operational for two years.

PM Collocation Requirements 

(40 CFR 58 Appendix A, Sections 3.2.5 and 3.2.6) 

The District’s Particulate Matter collocation requirements are met by the “Primary 

Quality Assurance Organization” (PQAO). ARB is the PQAO for the Valley as well as 

several other air basins. ARB has requested that the District to collocate one PM-10 

monitor. The Corcoran site serves this purpose. The AIRS codes for the collocated pair 

are: 06-031-0004-88102-1 (this is the primary monitor) and 06-031-0003-88102-3 (this 

is the collocated monitor). 

Public Review of Changes to the PM2.5 Monitoring Network 

Public input is required whenever the District proposes to move an existing violating 

PM2.5 monitor (40 CFR 58.10(c)). The District uses the annual Air Monitoring Network 

Plan to notify and seek public comment on any planned changes to the existing PM2.5 

network. The public has 30 days to comment on the Monitoring Network Plan and any 

PM2.5 network changes. The plan is posted on the District website, and public notice is 

published in a newspaper of general circulation in each affected CBSA. The 2011 

Monitoring Network Plan was posted for comment May 23, 2011, through June 21, 

2011. No public comments were received. 

In the event of unanticipated changes to the PM2.5 network that occur outside the 

Monitoring Network Plan process, the District will post public notice in Valley 

newspapers, post a document describing the proposed changes on its website, and 

seek public comment. 

Carbon Monoxide 

In the past, monitoring has shown that the Valley’s Carbon monoxide (CO) 

concentrations have not exceeded the NAAQS for over a decade. As noted in Section 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 31

 

4.2 of Appendix D of 40 CFR Part 58, there are no minimum requirements of the 

number of Carbon Monoxide (CO) monitoring sites. The District continues CO 

monitoring to supplement related meteorological and criteria pollutant data. Table 17 

summarizes the Valley’s past CO monitoring sites. 

Table 17 Carbon Monoxide Monitoring Stations in the San Joaquin Valley 

As of June 1, 2011 

Site Name Sampling 

Frequency Scale Site Type Objective 

Clovis–Villa Continuous Neighborhood Population Standards/ 

Strategy 

Fresno–

Drummond Continuous Neighborhood Population Standards/ Strategy 

Fresno–First Continuous Neighborhood Population Standards/ 

Strategy 

Fresno–Sky Park Continuous Neighborhood Population Standards/ 

Strategy 

Modesto–14th

Street Continuous Neighborhood Population Standards/ Strategy 

Stockton– 

Hazelton Continuous Neighborhood Population Standards/ Strategy 

Turlock Continuous Neighborhood Population Standards/ 

Strategy 

A proposed new CO rule (to issue a final rule on August 12, 2011), is proposing to 

retain the existing NAAQS for CO (the existing primary standards are 9 parts per million 

(ppm) measured over 8 hours, and 35 ppm measured over 1 hour). EPA is proposing 

to make changes to the ambient air monitoring requirements for CO, to include monitor 

placement near highly trafficked roads within urban populations of 1 million or more and 

to be collocated with Nitrogen dioxide (NO2) monitors (as part of the January, 2010 

revision to the NAAQS for NO2). Moving an existing monitor to a new location is

acceptable. 

EPA is also proposing that EPA Regional Administrators would have the authority to 

require additional monitoring in case-by-case circumstances, such as in areas impacted 

by major stationary CO sources, in urban downtown areas or urban street canyons, or 

in areas adversely impacted by meteorological and/or topographical influences. EPA is 

proposing that the required CO monitors would be operating by January 1, 2013. 

Nitrogen Dioxide 

EPA strengthened the health-based NAAQS for NO2, setting a new 1-hour NO2

standard at the level of 100 parts per billion (ppb) effective April 12, 2010. The 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 32

 

monitoring requirements for this new standard will be based upon population of an area 

as well as the annual average daily traffic (AADT) count. NO2 monitors that are 

required under this new standard are to be operational by January 1, 2013. Table 18 

summarizes the Valley’s NO2 monitoring stations. 

Table 18 NO2 Monitoring Stations in the San Joaquin Valley 

As of June 1, 2011 

Site Name Sampling 

Frequency Scale Site Type Objective 

Bakersfield– 

California Continuous Neighborhood Population Standards/ Strategy, 

Clovis–Villa Continuous Neighborhood High Concentration 

Standards/ 

Strategy, 

Research 

Edison Continuous Neighborhood Population Standards/ 

Strategy 

Fresno– 

Drummond Continuous Neighborhood High Concentration Standards/ Strategy 

Fresno–First Continuous Neighborhood Population Standards/ 

Strategy 

Fresno–Sky 

Park Continuous Neighborhood Population Standards/ Strategy 

Hanford--Irwin Continuous Neighborhood Population Standards/ 

Strategy 

Madera–Pump 

Yard Continuous Neighborhood Population 

Standards/ 

Strategy, 

Research 

Merced–Coffee Continuous Neighborhood Population Standards/ 

Strategy 

Parlier Continuous Neighborhood Population 

Standards/ 

Strategy, 

Research 

Shafter Continuous Neighborhood Population 

Standards/ 

Strategy, 

Research 

Stockton– 

Hazelton Continuous Neighborhood Population Standards/ Strategy 

Tracy–Airport Continuous Neighborhood Population Standards/ 

Strategy 

Turlock Continuous Neighborhood Population Standards/ 

Strategy 

Visalia--Church Continuous Neighborhood Population Standards/ 

Strategy 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 33

 

As noted in Section 4.3 of Appendix D of 40 CFR Part 58, one microscale near-road 

NO2 monitoring station is required in each CBSA with a population of 500,000 or more. 

Installation of four sites within the District is dependent upon securing funding from 

EPA. Existing Clean Air Act Section 105 funding is already fully allocated to operate the 

existing air monitoring network. Provided funding is secured, the District and CARB will 

collaborate in locating suitable sites for the four stations. One station will be installed in 

each of the following counties: San Joaquin, Stanislaus, Fresno, and the valley portion 

of Kern County. Near-road NO2 monitoring stations shall be sited near major roads 

with high AADT counts where maximum hourly NO2 concentrations are expected to 

occur. 

Although the Valley does not exceed federal or state standards for NO2, NOx reductions 

contribute to air quality improvement for both ozone and PM. A schedule to install 

equipment for measuring NO/NOy at the Arvin-Di Giorgio and Parlier monitoring sites is 

currently being determined. 

Sulfur Dioxide

For the years of 2010 through 2012 Section 4.4 of Appendix D of 40 CFR Part 58 does 

not specify any minimum requirements for the number of SO2 monitoring sites. 

Because the Valley does not exceed the federal standard for SO2, there is just one SO2

monitoring site in the Valley (shown in Table 19a). This monitor is operated by CARB 

and is part of the NCore Network. 

Table 19a SO2 Monitoring Station in the San Joaquin Valley 

As of June 1, 2010 

Site Name Sampling 

Frequency Scale Site Type Objective 

Fresno-First Continuous Neighborhood Population Standards/ 

Strategy 

EPA revised the SO2 NAAQS and monitoring requirements in the Federal Register on 

June 22, 2010 (CFR, 40 CFR Part 58, Section 4.4). The rule became effective on 

August 23, 2010). The number of monitor requirements is based upon CBSA’s most 

recently available census data multiplied with the total amount of SO2 in tons per year 

emitted from the most recently available data from the National Emissions Inventory for 

each county, divided by one million, providing a Populations Weighted Emissions Index 

(PWEI) value in units of million persons-tons per year (Table 19b). 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 34

 

Table 19b Populations Weighted Emissions Index for the San Joaquin Valley 

As of June 1, 2011 

County (CBSA) Total County 

Population1

SO2 Tons per 

Year2 PWEI 

Fresno 942,298 458 432 

Kern 827,173 2212 1,830 

Kings 154,743 55 9 

Madera 152,331 113 17 

Merced 256,450 66 17 

San Joaquin 689,480 1097 756 

Stanislaus 526,383 312 164 

Tulare 441,481 122 54 

1

 Total County Population includes the entire county. Population data was from the most recently available data from 

 the CA Department of Finance E-4 Population Estimates from Cites, Counties and the State, 2001-2009, with 2000 

 Benchmark. Estimates are for 1/1/2009. 

2

 SO2 Tons per Year includes the entire county. SO2 data is from the most recent data available from the 2008 

 National Emissions Inventory for each county. 

As per 40 CFR Part 58, Section 4.4, Appendix D any CBSA with a calculated value 

equal to or greater than 5,000, but less than 100,000, a minimum of one SO2 monitor is 

required within that CBSA. There are no minimum requirements for the number of SO2

monitoring sites in the District because the Valley does not exceed the federal standard 

for SO2.

Lead 

EPA revised the lead NAAQS and monitoring requirements in the Federal Register on 

November 12, 2008 (73 FR 66964 – 67062, codified in 40 CFR 58.10). The rule 

became effective on January 26, 2011 and requires monitoring agencies to install nonsource oriented lead monitors at NCore sites by December 27, 2011, in CBSAs that 

exceed a population of 500,000. The only site meeting these criteria within the District 

is Fresno-1st which is operated by the California Air Resources Board. The EPA is also 

requiring source-oriented lead monitoring at areas with a threshold of 1.0 ton per year 

(tpy). The District has not identified any sources at the 1.0 tpy threshold, thus sourceoriented monitoring is not required. 

Toxics 

Airborne toxic substances are monitored by the CARB at Bakersfield–California, 

Fresno--First, and Stockton–Hazelton. Periodic, 24-hour samples are analyzed for the 

following gases: benzene, Carbon tetrachloride, chloroform, ethylene dibromide, 

ethylene dichloride, methyl chloroform, methylene chloride, perchloroethylene, toluene, 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 35

 

trichloroethylene, and m-, p-, and o-xylene. The samples are also analyzed for the 

following particulate metals: arsenic and chromium-6. CARB’s Integrated NMOC 

sampling program and the District’s PAMS NMOC sampling program also identify and 

quantify several toxic hydrocarbon species. 

Green House Gases 

For the year 2010 CARB installed Picarro multi-gas analyzers (CO2, CH4, and water 

vapor) and a Teledyne-API 300 EU (CO) analyzer at the Madera-Pump Yard, 

Tranquillity, and Arvin sites. While the data will not be submitted to AQS at this time, the 

data will be used by CARB’s Research Division. CARB plans to continue monitoring 

Green House Gases (GHG) at these sites in 2011. 

NCore 

 EPA’s October 2006 ambient air monitoring amendments established a requirement for 

National Core (NCore) multi-pollutant monitoring stations. An NCore plan was to be 

submitted to EPA, and NCore stations must be operational by January 1, 2011. EPA 

selected the Fresno-First Street air monitoring station (operated by ARB) as an NCore 

site. 

ARB submitted an NCore plan to EPA in November 2009. Fresno--First already met 

NCore requirements for filter-based and continuous PM2.5, speciated PM2.5, ozone, 

and meteorology. ARB staff installed trace level CO, trace level SO2, trace level NOy, 

and continuous PM-Coarse monitors at this site in December 2010. ARB staff also 

installed a gas dilution calibrator, a zero air generator, and digital data loggers to 

support NCore monitoring. In December 2011, ARB staff will install a TSP-lead 

sampler, completing all the pollutant monitoring requirements for the NCore program. 

All the newly installed instrumentation will be reporting data to EPA’s AQS databases by 

the end of May 2011."

Meteorology 

Data for a variety of meteorological variables are collected to aid various programs 

affected by weather. Such programs include forecasting air quality, exceptional events, 

long-term planning, and pollutant trend assessment. These activities help protect public 

health and have made the public and media more aware of air quality and what can be 

done to reduce air pollution. See Table 20 for the meteorological parameters measured 

in the Valley. 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 36

 

Table 20 Meteorological Parameter Monitoring Stations in the San Joaquin Valley 

As of June 1, 2011 

Site Wind 

Speed 

Wind 

Direction 

Outdoor 

Temperature

Relative 

Humidity 

Barometric 

Pressure 

Solar 

Radiation

Arvin–Di Giorgio X 

Bakersfield–California X X X X X X 

Clovis–Villa X X X X X X 

Corcoran–Patterson X X X X 

Edison X X X 

Fresno–Drummond X X X X 

Fresno–First X X X X X 

Fresno--Sky Park X X X 

Hanford--Irwin X X X X 

Huron X 

Lebec X X X X 

Madera–City X X X X X X 

Madera–Pump Yard X X X X X X 

Manteca X X X X 

Maricopa X X X X 

Merced–Coffee X X X 

Modesto–14th Street X X X X 

Oildale X X X 

Parlier X X X X X X 

Porterville X X X X 

Santa Rosa Rancheria Unknown 

Sequoia–Ash Mountain X X X X X 

Sequoia–Lower 

Kaweah X X X X X 

Shafter X X X X X X 

Stockton–Hazelton X X X X 

Tracy–Airport X X X X 

Tranquillity X X X X 

Turlock X X X X 

Visalia–Church X X X X 

Visalia--Airport X X X X X X 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 37

 

Summary of completed changes, January 2010 – July 2011 

• The Arvin-Bear Mountain Blvd site operated by CARB had to be relocated due to an 

expired lease in 2010 so the Arvin-Di Giorgio monitoring site is intended to be the 

long-term replacement for the Arvin-Bear Mountain Blvd site. The Arvin-Di Giorgio 

site became operational in May 2010 and is operated by CARB. Parallel ozone 

monitoring was completed in November 2010 and the Arvin-Bear Mountain Blvd. site 

was then closed. 

The Arvin-Di Giorgio site is located 18 miles southeast of the Bakersfield, CA 

metropolitan area and is approximately 2 miles away from the old site. The purpose 

of the site is to monitor maximum ozone concentrations and transport from upwind 

urban areas. This site will also be a PAMS Type 3 site. The site also monitors NO2, 

NMOC, NMHC, and meteorology and CARB plans to install methane/CO2 and trace 

CO analyzers for special purpose monitoring. In addition, a NOy monitor will be 

added to the Arvin-Di Giorgio air monitoring site to comply with the latest regulation 

for PAMS Type 3 sites. 

 

• CARB installed Picarro multi-gas analyzers (CO2, CH4, and water vapor) and a 

Teledyne-API 300 EU (CO) analyzer at the Madera-Pump Yard, Tranquillity, and 

Arvin Di-Giorgio sites as part of its GHG monitoring program. While the data will not 

be submitted to AQS at this time, the data will be used by CARB’s Research 

Division. 

• A system-wide change that was made in 2010 was the addition of ammonia 

denuders to all of the NOx analyzers at all of the District sites than measure NOx. 

• Anderson sampling instruments at the Fresno-Pacific, Merced-M Street, and 

Corcoran monitoring sites have been replaced with Partisol Units. 

• Three new monitoring stations were installed and became operational in the District 

in 2010. The Manteca site monitors PM2.5, PM10, and meteorology, the MaderaCity site monitors ozone, PM2.5, PM10, and meteorology, and the Porterville site 

monitors ozone, PM2.5, and meteorology. 

 

• The Hanford monitoring station has been operational for many years and over time 

had become dilapidated and in need of repairs. The site underwent reconstruction 

in 2009 and was finished and resumed operations in February 2010. 

Summary of planned changes, July 2011 – December 2011 

The Valley air monitoring network is continually being improved. As one overall change, 

the District will be replacing filter-based PM monitors with continuous, real-time PM2.5 

and real-time PM10 monitors in the future, particularly in rural areas. These monitors 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 38

 

are more economically efficient than filter-based monitors and give the District more 

data for forecasting. Simultaneously, the District will be investigating to see how realtime data compares to filter-based data at sites with parallel monitoring. 

The planned site-specific changes are described below. 

Once funding is secured from EPA, the District and CARB will begin the process of 

finding locations for four microscale near-road NO2 monitoring stations that will be 

installed within the District’s boundaries to meet the requirement listed in Section 4.3 of 

Appendix D of 40 CFR Part 58. One station will be installed in each of the following 

counties: San Joaquin, Stanislaus, Fresno, and the Valley portion of Kern County. 

Stockton CBSA/MSA 

A PM10 TEOM Special Purpose Monitor (SPM) has been installed at the Manteca site 

to compare with PM10 measurements from the Stockton Wagner/Holt PM10 monitor. If 

the results show that the measurement prove similar enough, the Wagner/Holt monitor 

will be shut down and a permanent PM10 monitor (TEOM) will be installed at Manteca. 

Modesto CBSA/MSA 

The District does not have any changes scheduled for this MSA during this time. 

Merced CBSA/MSA 

The District does not have any changes scheduled for this MSA during this time. The 

District’s long-term plan is to investigate consolidating the Merced-Coffee and MercedM Street sites. No changes are planned at this time. 

Madera CBSA/MSA 

The District does not have any changes scheduled for this MSA during this time. 

Fresno CBSA/MSA 

Recently planted vegetation on adjacent property may require the District to relocate the 

Fresno-Sky Park site sometime over the next few years. There are no definite 

relocation plans at this time. 

In addition, a NOy monitor will be added to the Parlier air monitoring site to comply with 

the latest regulation for PAMS Type 3 sites. 

Hanford-Corcoran CBSA/MSA 

The District does not have any changes scheduled for this MSA during this time. 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 39

 

Visalia-Porterville CBSA/MSA 

The District does not have any changes scheduled for this MSA during this time. 

Bakersfield CBSA/MSA 

In December 2009, the Bakersfield-Golden site was shut down for relocation due to 

adjacent highway expansion. The replacement site, Bakersfield-Muni, will be located at 

the Bakersfield Municipal Airport in the Bakersfield, CA and will be about 790 meters 

(0.5 miles) away from CARB’s Bakersfield-Planz site. This location was chosen 

because the airport’s runway, most of the airport activities, and the dirt fields in the area 

are an ample distance away, and a sufficient power source is nearby. The District plans 

to have the Bakersfield-Muni site operational in October 2011 and will be operated by 

the SJVAPCD. This site will measure maximum ozone precursor emissions and will 

serve as a PAMS Type 2 site. The District plans to install analyzers for ozone, PM10 

TEOM, PM2.5 BAM (non-regulatory), CO, NO2, NMOC (PAMS), NMHC. Instruments 

for monitoring meteorology will also be installed. Once this Bakersfield-Muni site is 

operational, it is anticipated that the Bakersfield-Planz monitoring station will be 

relocated to the Bakersfield-Muni site and the Bakersfield-Planz site will be closed. 

After the shutdown of the Bakersfield-Golden site, the District requested CARB’s 

permission to temporarily operate a real time PM10 monitor at the Bakersfield-California 

site (06-029-0014). The sampler (a BAM PM10 FEM) began to operate in March, and its 

real-time data will contribute to the District’s production of more accurate daily AQI 

forecasting. When the relocation of the new site is completed, this BAM monitor will be 

removed and the new site will continue PM10 monitoring with the established TEOM 

sampler. 

The Arvin-Di Giorgio site will to monitor maximum ozone concentrations and transport 

from upwind urban areas, and serve as a PAMS Type 3 site (SLAMS). An NOy monitor 

will be added to the Arvin-Di Giorgio air monitoring site to comply with the latest 

regulation for PAMS Type 3 sites. Plans to construct a building at the Arvin-DiGiorgio 

site for monitoring NO2 are being determined. CARB also plans to install methane/CO2

and trace CO analyzers for special purpose monitoring. 

Construction of shelters and installation of PAMS equipment for the Bakersfield-Muni 

and Arvin-Di Giorgio sites are planned but will not be completed in time for the 2011 

PAMS season so these PAMS sites will be down during that time. 

Data Submission Requirements 

Precision data are submitted to AQS on an ongoing basis each quarter as the data is 

uploaded into AQS. The accuracy data is submitted into AQS by CARB based on their 

scheduled audits. The District submitted its 2010 data certification to the EPA. Annual 

certifications are due by May 1 of each year. 
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 40

 

Acronyms, Abbreviations, and Initialisms 

AIRS: Aerometric Information Retrieval System; replaced with AQS 

AQI: Air Quality Index 

AQS: Air Quality System 

CARB: California Air Resources Board 

ARM: approved regional method 

BAM: beta attenuation monitor 

CAA: Clean Air Act 

CBSA: Core-based statistical area 

CCOS: Central California Ozone Study 

CFR: Code of Federal Regulations 

CRPAQS: California Regional Particulate Air Quality Study 

CO: Carbon Monoxide 

CO2: Carbon Dioxide 

CSA: Combined statistical area 

District: San Joaquin Valley Air Pollution Control District 

EBAM: environmental beta attenuation monitor 

EPA: U.S. Environmental Protection Agency 

FEM: Federal Equivalent Method 

FIPS: Federal information processing standard 

FR: Federal Register 

FRM: Federal Reference Method 

GHG: green house gases 

MSA: Metropolitan statistical area 

NAAQS: National Ambient Air Quality Standard 

NCore: National Core 

NMHC: Non-methane hydrocarbons 

NMOC: non-methane organic carbons 

NO2: Nitrogen Dioxide 

NOAA: National Oceanic and Atmospheric Administration 

NOx: oxides of nitrogen 

NOy: reactive nitrogen 

NPS: National Park Service 

O3: ozone 

PAMS: Photochemical Assessment Monitoring Station 

Pb: lead 

PM: particulate matter 

PM2.5: particulate matter 2.5 microns or less in diameter 

PM10: particulate matter 10 microns or less in diameter 

SLAMS: State and Local Air Monitoring Station 

SJV: San Joaquin Valley 

SJVAPCD: San Joaquin Valley Air Pollution Control District 

SMS: Smoke Management System 

SO2: Sulfur Dioxide 

SPM: Special Purpose Monitor 

STN: Speciated Trends Network 

TEOM: Tapered Element Oscillating Microbalance 

TSP: total suspended particles 

Valley: San Joaquin Valley 

VOC: Volatile Organic Compounds
San Joaquin Valley Unified Air Pollution Control District

2011 Air Monitoring Network Plan 41

 

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San Joaquin Valley Air Pollution Control District June 30, 2011

Appendix A: Air Monitoring Site Descriptions 

2011 Air Monitoring Network Plan 

 

A-1

Appendix A: Monitoring Site Descriptions

Sites operated by the SJVAPCD

Bakersfield-Muni 

The Bakersfield-Golden site was shut down for relocation in December 2009. The 

replacement site, Bakersfield-Muni, will be located in the Bakersfield, CA metropolitan 

area. The Bakersfield-Muni site will begin operating in October 2011 and will be 

operated by the SJVAPCD. This site will serve as a PAMS Type 2 site, sited to 

measure maximum ozone precursor emissions and will monitor ozone, PM10 TEOM, 

PM2.5 BAM (non-regulatory), CO, NO2, NMOC (PAMS), NMHC, and meteorology. 

Bakersfield, CA is located at the southern end of the San Joaquin Valley with mountains 

to the east, west, and south. Because the mountains block or slow down air flow, 

pollutants can get trapped and build up in the area. Pollutants occur locally and also get 

transported from upwind locations into the area by the wind. During the summer 

months, high temperatures and longer daylight hours contribute to increases in ozone 

during the day. In contrast, ozone concentrations decrease at night with the absence of 

sunlight and the presence of NOx pollutants, which scavenge the ozone. During the 

winter months, ozone concentrations decrease due to shorter daylight hours and lower 

temperatures. Elevated PM2.5 concentrations are possible year round, but 

concentrations tend to be highest during the winter months due to moisture content in 

the air, wood burning activities, other anthropogenic activities, and atmospheric 

chemistry. PM2.5 concentrations can also increase during wind blown dust events, 

when the wind can cause PM2.5 to become suspended in the air. On rare occasions, 

this region of the San Joaquin Valley experiences wind events that can carry dust into 

the area or lift local dust particles into the air. Such events can cause PM10 

concentrations to increase and sometimes exceed the NAAQS. 

Clovis-Villa 

Clovis, CA is located in the central part of the San Joaquin Valley with mountains to the 

east and northeast. North-south air flow is virtually unobstructed. Pollutant emissions 

occur locally and are also transported from upwind and nearby locations into the area 

by the wind. The Clovis-Villa monitoring site is operated by SJVAPCD and is located in 

the northeastern portion of the Fresno, CA metropolitan area. It began operating in 

September 1990. This site is a PAMS Type 2 site, a site intended to measure 

maximum ozone precursor emissions. In addition to ozone (SLAMS), the site also 

monitors PM2.5 (BAM FEM/SLAMS), PM10 (FRM, SLAMS), CO, NO2, NMOC, NMHC, 

and meteorology. During the summer months, high temperatures and longer daylight 

hours contribute to increases in ozone during the day. In contrast, ozone 

concentrations decrease at night with the absence of sunlight and the presence of NOx 

pollutants, which scavenge the ozone. During the winter months, ozone concentrations 

tend to be lower due to shorter daylight hours and lower temperatures. Elevated PM2.5 

concentrations are possible year round, but concentrations tend to be highest during the 

winter months due to moisture content in the air, wood burning activities, other 

anthropogenic activities, and atmospheric chemistry. PM2.5 concentrations can also 
San Joaquin Valley Air Pollution Control District June 30, 2011

Appendix A: Air Monitoring Site Descriptions 

2011 Air Monitoring Network Plan 

 

A-2

increase during wind events because the wind can cause PM2.5 to become suspended 

in the air. On rare occasions, this area of the San Joaquin Valley experiences wind 

events that can carry dust into the area or lift local dust particles into the air. Such 

events can cause PM10 concentrations to increase. 

Corcoran-Patterson 

Corcoran, CA is located in the central part of the San Joaquin Valley with mountains to 

the east and west. North-south air flow is virtually unobstructed. Pollutant emissions 

occur locally and also get transported from upwind locations into the area by the wind. 

The Corcoran-Patterson monitoring site is operated by SJVAPCD and is located 67 

miles south of the Fresno, CA metropolitan area. It began operating in October 1996. 

The purpose of the site is to monitor representative concentrations of PM10 (TEOM and 

FRM, both SLAMS) and PM2.5 (FRM, SLAMS and a BAM SPM) and responses from 

surrounding areas. This site also monitors meteorology. Elevated PM2.5 

concentrations are possible year round, but concentrations tend to be highest during the 

winter months due to moisture content in the air, wood burning activities, other 

anthropogenic activities, and atmospheric chemistry. PM2.5 concentrations can also 

increase during wind events because the wind can cause PM2.5 to become suspended 

in the air. On rare occasions, this area of the San Joaquin Valley experiences wind 

events that can carry dust into the area or lift local dust particles into the air. Such 

events can cause PM10 concentrations to increase. 

 

Fresno-Drummond 

Fresno, CA is located in the central part of the San Joaquin Valley with mountains to the 

east and west. North-south air flow is virtually unobstructed. Pollutants occur locally 

and also get transported from upwind locations into the area by the wind. The FresnoDrummond monitoring site is operated by SJVAPCD and is located in the Fresno, CA 

metropolitan area. It began operating in July 1984. The purpose of the site is to 

monitor representative concentrations of hourly ozone responses in an urban area. In 

addition to ozone (SLAMS), the site also monitors PM10 (FRM, SLAMS), CO, NO2, and 

meteorology. During the summer months, high temperatures and longer daylight hours 

contribute to increases in ozone during the day. In contrast, ozone concentrations 

decrease at night with the absence of sunlight and the presence of NOx pollutants 

which scavenge the ozone. During the winter months, ozone concentrations tend to be 

lower due to shorter daylight hours and lower temperatures. 

Fresno-Pacific 

Fresno, CA is located in the central part of the San Joaquin Valley with mountains to the 

east and west. North-south air flow is virtually unobstructed. Pollutants occur locally 

and also get transported from upwind locations into the area by the wind. The FresnoPacific monitoring site is operated by SJVAPCD and is located in the Fresno, CA 

metropolitan area. It began operating in January 2000. The purpose of the site is to 

monitor representative PM2.5 (FRM, SLAMS) concentrations in an urban area. 

Elevated PM2.5 concentrations are possible year round, but concentrations tend to be 

highest during the winter months due to moisture content in the air, wood burning 
San Joaquin Valley Air Pollution Control District June 30, 2011

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2011 Air Monitoring Network Plan 

 

A-3

activities, other anthropogenic activities, and atmospheric chemistry. PM2.5 

concentrations can also increase during wind events because the wind can cause 

PM2.5 to become suspended in the air. On rare occasions, this area of the San 

Joaquin Valley experiences wind events that can carry dust into the area or lift local 

dust particles into the air. Such events can cause PM10 concentrations to increase. 

Fresno-Sky Park 

Fresno, CA is located in the central part of the San Joaquin Valley with mountains to the 

east and west. Pollutants occur locally and also get transported from upwind locations 

into the area by the wind. The Fresno-Sky Park monitoring site is operated by 

SJVAPCD and is located in the Fresno, CA metropolitan area. It began operating in 

July 1986. The purpose of the site is to monitor representative concentrations of hourly 

ozone responses in an urban area. In addition to ozone (SLAMS), the site also 

monitors CO, NO2, and meteorology. During the summer months, high temperatures 

and longer daylight hours contribute to increases in ozone during the day. In contrast, 

ozone concentrations decrease at night with the absence of sunlight and the presence 

of NOx pollutants which scavenge the ozone. During the winter months, ozone 

concentrations tend to be lower due to shorter daylight hours and lower temperatures. . 

Hanford-Irwin 

Hanford, CA is located in the central part of the San Joaquin Valley with mountains to 

the east and west. North-south air flow is virtually unobstructed. Pollutants occur 

locally and also get transported from upwind locations into the area by the wind. The 

Hanford-Irwin monitoring site is operated by SJVAPCD and is located 51 miles south of 

the Fresno, CA metropolitan area. The site began operating in October 1993 and was 

decommissioned in October 2007 due to plans to move it to a different part of the Irwin 

location. The purpose of the site is to monitor representative concentrations of hourly 

ozone, PM2.5, and PM10 (FRM and TEOM, both SLAMS) responses from upwind and 

nearby urban areas. The PM2.5, PM10, and ozone monitors were temporarily moved to 

Corcoran during site reconstruction. In February 2010, the ozone (SLAMS) and PM2.5 

(BAM, SLAMS) monitors were returned to Hanford and the site became operational 

again. The PM10 monitor was returned and became operational in July 2010. During 

the summer months, high temperatures and longer daylight hours contribute to 

increases in ozone during the day. In contrast, ozone concentrations decrease at night 

with the absence of sunlight and the presence of NOx pollutants which scavenge the 

ozone. During the winter months, ozone concentrations tend to be lower due to shorter 

daylight hours and lower temperatures. Elevated PM2.5 concentrations are possible 

year round, but concentrations tend to be highest during the winter months due to 

moisture content in the air, wood burning activities, other anthropogenic activities, and 

atmospheric chemistry. PM2.5 concentrations can also increase during wind events 

because the wind can cause PM2.5 to become suspended in the air. On rare 

occasions, this area of the San Joaquin Valley experiences wind events that can carry 

dust into the area or lift local dust particles into the air. Such events can cause PM10 

concentrations to increase. 
San Joaquin Valley Air Pollution Control District June 30, 2011

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2011 Air Monitoring Network Plan 

 

A-4

Huron 

Huron, CA is located in southwestern Fresno County, and is about 40 miles southwest 

of Fresno, CA, with the coastal mountain range just to the west. North-south air flow is 

virtually unobstructed. This monitoring site was established in January 2007 in order to 

comply with Assembly Bill (AB) 841. Currently, this site only measures PM2.5 (SPM), 

as required by AB 841. 

Lebec 

Lebec, CA is located in the southern-most portion of the San Joaquin Valley. The 

Lebec monitoring station was initiated by the Tejon Ranch in 2004, and the District 

assumed responsibility for this site as of January 2009. This site allows the District to 

better understand pollution impacts in the southern San Emigdio Mountains. The site 

measures meteorological parameters and PM2.5 (SPM). This site will be used for 

general residential wood burning declarations for the Greater Frazier Park Area in the 

future. The site is not yet reported on AQS. 

Madera-City 

Madera, CA is located in the northern part of the San Joaquin Valley with mountains to 

the east and west. North-south air flow is virtually unobstructed. The Madera-City 

monitoring site is located closer to the city center of Madera than the Madera-Pump 

Yard site. The Madera-City site is operated by the SJVAPCD and became operational 

in June 2010. The site monitors ozone (SLAMS), PM2.5 (BAM FEM, SLAMS), PM10 

(TEOM, SLAMS), and meteorology. The purpose of this site is to measure down wind 

concentrations of the city of Madera which will provide needed information about the 

variability of air quality levels on the Valley floor of Madera County.

Madera-Pump Yard 

Madera, CA is located in the northern part of the San Joaquin Valley with mountains to 

the east and west. North-south air flow is virtually unobstructed. Pollutants occur 

locally but the wind also transports pollutants into the area from upwind locations. The 

Madera-Pump Yard Street monitoring site is operated by SJVAPCD and is located in 

the Madera, CA. It began operating in August 1997. This site was established as a 

PAMS Type 1 site, located in an area upwind of Fresno and not to be influenced by 

upwind or local ozone precursor emissions. In addition to ozone (SLAMS), this site also 

monitors CO, NMOC, NMHC, and meteorology. During the summer months, high 

temperatures and longer daylight hours contribute to increases in ozone during the day. 

In contrast, ozone concentrations decrease at night with the absence of sunlight and the 

presence of NOx pollutants which scavenge the ozone. During the winter months, 

ozone concentrations tend to be lower due to shorter daylight hours and lower 

temperatures. 

Manteca

Manteca, CA is located in the northern part of the San Joaquin Valley with mountains to 

the east and west. North-south air flow is virtually unobstructed. Pollutants occur 

locally but the wind also transports pollutants into the area from upwind locations or 
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through the Sacramento Delta from the Bay Area. The Manteca monitoring site is 

operated by SJVAPCD is located in Manteca, CA operated by SJVAPCD. It became 

operational in November 2010. The purpose of the site is to monitor transport of and 

representative concentrations of PM2.5 (BAM/FEM, SLAMS), and PM10 (TEOM, 

SLAMS) from upwind and nearby urban areas. The site also monitors meteorology. 

During the winter months, ozone concentrations tend to be lower due to shorter daylight 

hours and lower temperatures. Elevated PM2.5 concentrations are possible year round, 

but concentrations tend to be highest during the winter months due to moisture content 

in the air, wood burning activities, other anthropogenic activities, and atmospheric 

chemistry. PM2.5 concentrations can also increase during wind events because the 

wind can cause PM2.5 to become suspended in the air. Occasionally, wind will carry 

dust across the city and cause PM10 concentrations to increase, but PM10 and PM2.5 

exceedances due to wind events are rare. 

Maricopa 

Maricopa, CA is located at the southern end of the San Joaquin Valley with mountains 

to the east, west, and south. Because the mountains block or slow down air flow 

pollutants can get trapped and build up in the area. The Maricopa monitoring site is 

operated by the SJVAPCD and is located 45 miles southwest of the Bakersfield, CA 

metropolitan area. It began operating in July 1987. The purpose of the site is to 

monitor representative concentrations of hourly ozone (SLAMS) in a rural area. The 

site also monitors meteorology. During the summer months, high temperatures and 

longer daylight hours contribute to increases in ozone during the day. In contrast, 

ozone concentrations decrease at night with the absence of sunlight and the presence 

of NOx pollutants which scavenge the ozone. During the winter months, ozone 

concentrations tend to be lower due to shorter daylight hours and lower temperatures. 

Merced-Coffee 

Merced, CA is located in the northern part of the San Joaquin Valley with mountains to 

the east and west. North-south air flow is virtually unobstructed. Pollutants occur 

locally but the wind also transports pollutants into the area from upwind locations. The 

Merced-Coffee monitoring site is operated by SJVAPCD and is located in the Merced, 

CA. It began operating in October 1991. The purpose of the site is to monitor 

representative concentrations of hourly ozone (SLAMS) responses from upwind urban 

areas. The site also monitors PM2.5 (SPM), NO2, and meteorology. During the 

summer months, high temperatures and longer daylight hours contribute to increases in 

ozone during the day. In contrast, ozone concentrations decrease at night with the 

absence of sunlight and the presence of NOx pollutants which scavenge the ozone. 

During the winter months, ozone concentrations tend to be lower due to shorter daylight 

hours and lower temperatures. 

Merced-M Street

Merced, CA is located in the northern part of the San Joaquin Valley with mountains to 

the east and west. North-south air flow is virtually unobstructed. Pollutants occur 

locally but the wind also transports pollutants into the area from upwind locations. The 
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Merced-M Street monitoring site is operated by SJVAPCD and is located in the Merced, 

CA. It began operating in April 1999. The purpose of the site is to monitor 

representative concentrations of PM2.5 (FRM, SLAMS) and PM10 (FRM, SLAMS) 

responses from upwind urban areas. Elevated PM2.5 concentrations are possible year 

round, but concentrations tend to be highest during the winter months due to moisture 

content in the air, wood burning activities, other anthropogenic activities, and 

atmospheric chemistry. PM2.5 concentrations can also increase during wind events 

because the wind can cause PM2.5 to become suspended in the air. Occasionally, 

wind will carry dust across the city and cause PM10 concentrations to increase, but 

PM10 exceedances are rare. 

Parlier 

Parlier, CA is located in the central part of the San Joaquin Valley with mountains to the 

east and west. North-south air flow is virtually unobstructed. Pollutants occur locally 

and also get transported from upwind locations into the area by the wind. The Parlier 

monitoring site is operated by SJVAPCD and is located 20 miles southeast of the 

Fresno, CA metropolitan area. It began operating in March 1983. The purpose of the 

site, as a PAMS Type 3 site, is to monitor maximum ozone concentrations (SLAMS) and 

ozone responses from upwind urban areas. The site also monitors NO2, NMOC, 

NMHC, and meteorology. During the summer months, high temperatures and longer 

daylight hours contribute to increases in ozone during the day. In contrast, ozone 

concentrations decrease at night with the absence of sunlight and the presence of NOx 

pollutants which scavenge the ozone. During the winter months, ozone concentrations 

tend to be lower due to shorter daylight hours and lower temperatures. 

Porterville 

Porterville, CA is located in the southern part of the San Joaquin Valley near the 

foothills of the Sierra Nevada Mountains to the east. It is approximately 25 miles 

southeast of Visalia, CA, and so transport of pollutants from Visalia towards Porterville 

is possible. The site monitors ozone (SLAMS), PM2.5 (BAM, SPM), and meteorology. 

The purpose of this site is to represent air quality levels present near the foothills of the 

southern Valley and give the district an indication of exposure of pollutants to the local 

population.

Stockton-Wagner/Holt 

Stockton, CA is located in the northern part of the San Joaquin Valley with mountains to 

the east and west. North-south air flow is virtually unobstructed. Pollutants occur 

locally but the wind also transports pollutants into the area from upwind locations or 

through the Sacramento Delta from the Bay Area. The Stockton-Wagner/Holt 

monitoring site is operated by SJVAPCD and is located in the Stockton, CA 

metropolitan area. It began operating in October 1996. The purpose of the site is to 

monitor representative concentrations of PM10 (FRM, SLAMS) in an urban area. 

Occasionally, wind will carry dust across the city and cause PM10 concentrations to 

increase, but PM10 exceedances are rare. 
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Tracy-Airport 

Tracy, CA is located in the northern part of the San Joaquin Valley with mountains to 

the east and west. North-south air flow is virtually unobstructed. Pollutants occur 

locally but the wind also transports pollutants into the area from upwind locations or 

through the Sacramento Delta from the Bay Area. The Tracy-Airport monitoring site is 

operated by SJVAPCD and is located in Tracy, CA. It began operating in January 2005. 

The purpose of the site is to monitor transport of ozone (SLAMS), PM2.5 (BAM, SPM), 

and PM10 (TEOM, SLAMS) from upwind and nearby urban areas. The site also 

monitors NO2 and meteorology. During the summer months, high temperatures and 

longer daylight hours contribute to increases in ozone during the day. In contrast, 

ozone concentrations decrease at night with the absence of sunlight and the presence 

of NOx pollutants which scavenge the ozone. During the winter months, ozone 

concentrations tend to be lower due to shorter daylight hours and lower temperatures. 

Elevated PM2.5 concentrations are possible year round, but concentrations tend to be 

highest during the winter months due to moisture content in the air, wood burning 

activities, other anthropogenic activities, and atmospheric chemistry. PM2.5 

concentrations can also increase during wind events because the wind can cause 

PM2.5 to become suspended in the air. Occasionally, wind will carry dust across the 

city and cause PM10 concentrations to increase, but PM10 exceedances are rare. 

Tranquillity 

Tranquillity, CA is located in western Fresno County, and is about 25 miles west of 

Fresno, CA, with the coastal mountain range just to the west. North-south air flow is 

virtually unobstructed. This monitoring site was established in November 2009 for 

research purposes, in an effort to better understand the Valley’s background and rural 

pollutant concentrations. This site measures ozone (SPM), PM2.5 (BAM, SPM) and 

meteorological parameters. 

Turlock 

Turlock, CA is located in the northern part of the San Joaquin Valley with mountains to 

the east and west. North-south air flow is virtually unobstructed. Pollutants occur 

locally but the wind also transports pollutants into the area from upwind locations or 

through the Sacramento Delta from the Bay Area. The Turlock monitoring site is 

operated by SJVAPCD and is located in the Turlock, CA. It began operating in April 

1992. The purpose of the site is to monitor representative concentrations of hourly 

ozone (SLAMS), PM2.5 (BAM FEM, SLAMS), and PM10 (FRM, SLAMS) responses 

from upwind urban areas. The site also monitors CO, NO2, and meteorology. During 

the summer months, high temperatures and longer daylight hours contribute to 

increases in ozone during the day. In contrast, ozone concentrations decrease at night 

with the absence of sunlight and the presence of NOx pollutants which scavenge the 

ozone. During the winter months, ozone concentrations tend to be lower due to shorter 

daylight hours and lower temperatures. Elevated PM2.5 concentrations are possible 

year round, but concentrations tend to be highest during the winter months due to 

moisture content in the air, wood burning activities, other anthropogenic activities, and 

atmospheric chemistry. PM2.5 concentrations can also increase during wind events 
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because the wind can cause PM2.5 to become suspended in the air. Occasionally, 

wind will carry dust across the city and cause PM10 concentrations to increase, but 

PM10 exceedances are rare. 

Visalia-Airport 

Visalia, CA is located where the central and southern parts of the San Joaquin Valley 

meet. The Sierra Nevada mountain range is approximately 20 miles east of Visalia. 

North-south air flow is virtually unobstructed. The Visalia-Airport monitoring site is 

operated by SJVAPCD and serves as a wind profiler monitoring surface wind speed and 

wind direction. It also monitors air temperature, and relative humidity at the surface. It 

began reporting official meteorological data in January 2001. Meteorological 

parameters have a direct influence on how and where pollutants are transported and 

how much pollutant concentrations increase or decrease.

Sites Operated by the CARB

Arvin-Di Giorgio 

Arvin, CA is located at the southern end of the San Joaquin Valley with mountains to the 

east, west, and south. Because the mountains block or slow down air flow pollutants 

can get trapped and build up in the area. Pollutants occur locally and also get 

transported from upwind locations into the area by the wind. The Arvin-Di Giorgio site is 

located 18 miles southeast of the Bakersfield, CA metropolitan area. The purpose of 

the site, as a PAMS Type 3 site (SLAMS), is to monitor maximum ozone concentrations 

and transport from upwind urban areas. The site also monitors NO2, NMOC, NMHC, 

and meteorology and CARB plans to install methane/CO2 and trace CO analyzers for 

special purpose monitoring. In addition, a NOy monitor will be added to the Arvin-Di 

Giorgio air monitoring site to comply with the latest regulation for PAMS Type 3 sites. 

During the summer months, high temperatures and longer daylight hours contribute to 

increases in ozone during the day. In contrast, ozone concentrations decrease at night 

with the absence of sunlight and the presence of NOx pollutants which scavenge the 

ozone. During the winter months, ozone concentrations decrease due to shorter 

daylight hours and lower temperatures. Pollutants occur locally and also get 

transported into the area by wind. 

Bakersfield-Planz

Bakersfield, CA is located at the southern end of the San Joaquin Valley with mountains 

to the east, west, and south. Because the mountains block or slow down air flow 

pollutants can get trapped and build up in the area. Pollutants occur locally and also get 

transported from upwind locations into the area by the wind. The Bakersfield-Planz 

monitoring site is operated by CARB and is located 6 miles north of the Bakersfield, CA 

metropolitan area. It began operating in September 2000. The purpose of the site is to 

monitor representative concentrations of PM2.5 (FRM, SLAMS) from upwind and 

nearby urban areas. Elevated PM2.5 concentrations are possible year round, but 

concentrations tend to be highest during the winter months due to moisture content in 

the air, wood burning activities, other anthropogenic activities, and atmospheric 
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chemistry. PM2.5 concentrations can also increase during wind events because the 

wind can cause PM2.5 to become suspended in the air. 

Bakersfield-California 

Bakersfield, CA is located at the southern end of the San Joaquin Valley with mountains 

to the east, west, and south. Because the mountains block or slow down air flow 

pollutants can get trapped and build up in the area. Pollutants occur locally and also get 

transported from upwind locations into the area by the wind. The Bakersfield-California 

monitoring site is operated by CARB and is located in the Bakersfield, CA metropolitan 

area. It began operating in March 1994. The purpose of the site is to monitor 

representative concentrations of hourly and daily ozone (SLAMS), PM10 (FRM and 

BAM FEM, both SLAMS), and PM2.5 (FRM and BAM FEM, bother SLAMS) responses 

in an urban area. The site also monitors NO2 and meteorology. During the summer 

months, high temperatures and longer daylight hours contribute to increases in ozone 

during the day. In contrast, ozone concentrations decrease at night with the absence of 

sunlight and the presence of NOx pollutants which scavenge the ozone. Elevated 

PM2.5 concentrations are possible year round, but concentrations tend to be highest 

during the winter months due to moisture content in the air, wood burning activities, 

other anthropogenic activities, and atmospheric chemistry. PM2.5 concentrations can 

also increase during wind events because the wind can cause PM2.5 to become 

suspended in the air. 

Edison 

Edison, CA is located at the southern end of the San Joaquin Valley with mountains to 

the east, west, and south. Because the mountains block or slow down air flow 

pollutants can get trapped and build up in the area. Pollutants occur locally and also get 

transported from upwind locations into the area by the wind. The Edison monitoring site 

is operated by CARB and is located 9 miles east of the Bakersfield, CA metropolitan 

area. It began operating in January 1980. The purpose of the site is to monitor 

representative concentrations of hourly ozone (SLAMS) from upwind and nearby urban 

areas. The site also monitors NO2 and meteorology. During the summer months, high 

temperatures and longer daylight hours contribute to increases in ozone during the day. 

In contrast, ozone concentrations decrease at night with the absence of sunlight and the 

presence of NOx pollutants which scavenge the ozone. During the winter months, 

ozone concentrations decrease due to shorter daylight hours and lower temperatures. 

Fresno-First 

Fresno, CA is located in the central part of the San Joaquin Valley with mountains to the 

east and west. North-south air flow is virtually unobstructed. Pollutants occur locally 

and also get transported from upwind locations into the area by the wind. The FresnoFirst monitoring site is operated by CARB and is located in the Fresno, CA metropolitan 

area. It began operating in January 1990. The purpose of the site is to monitor 

representative concentrations of hourly ozone (SLAMS), PM2.5 (FRM and BAM, both 

SLAMS), and PM10 (FRM and BAM, both SLAMS) responses in an urban area. The 

site also monitors CO, NO2, SO2, NMOC, NMHC, toxics, and meteorology. During the 
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summer months, high temperatures and longer daylight hours contribute to increases in 

ozone during the day. In contrast, ozone concentrations decrease at night with the 

absence of sunlight and the presence of NOx pollutants which scavenge the ozone. 

During the winter months, ozone concentrations tend to be lower due to shorter daylight 

hours and lower temperatures. Elevated PM2.5 concentrations are possible year round, 

but concentrations tend to be highest during the winter months due to moisture content 

in the air, wood burning activities, other anthropogenic activities, and atmospheric 

chemistry. PM2.5 concentrations can also increase during wind events because the 

wind can cause PM2.5 to become suspended in the air. On rare occasions, this area of 

the San Joaquin Valley experiences wind events that can carry dust into the area or lift 

local dust particles into the air. Such events can cause PM10 concentrations to 

increase. 

Modesto-14th Street 

Modesto, CA is located in the northern part of the San Joaquin Valley with mountains to 

the east and west. North-south air flow is virtually unobstructed. Pollutants occur 

locally but the wind also transports pollutants into the area from upwind locations or 

through the Sacramento Delta from the Bay Area. The Modesto-14th Street monitoring 

site is operated by CARB and is located in the Modesto, CA metropolitan area. It began 

operating in January 1981. The purpose of the site is to monitor representative 

concentrations of hourly ozone (SLAMS), PM2.5 (FRM and BAM, both SLAMS), and 

PM10 (FRM, SLAMS)responses in local and upwind urban areas. The site also 

monitors CO and meteorology. During the summer months, high temperatures and 

longer daylight hours contribute to increases in ozone during the day. In contrast, 

ozone concentrations decrease at night with the absence of sunlight and the presence 

of NOx pollutants which scavenge the ozone. During the winter months, ozone 

concentrations tend to be lower due to shorter daylight hours and lower temperatures. 

Elevated PM2.5 concentrations are possible year round, but concentrations tend to be 

highest during the winter months due to moisture content in the air, wood burning 

activities, other anthropogenic activities, and atmospheric chemistry. PM2.5 

concentrations can also increase during wind events because the wind can cause 

PM2.5 to become suspended in the air. Occasionally, wind will carry dust across the 

city and cause PM10 concentrations to increase, but PM10 exceedances are rare. 

Oildale 

Oildale, CA is located at the southern end of the San Joaquin Valley with mountains to 

the east, west, and south. Because the mountains block or slow down air flow 

pollutants can get trapped and build up in the area. Pollutants occur locally and also get 

transported from upwind locations into the area by the wind. The Oildale monitoring site 

is operated by CARB and is located 6 miles north of Bakersfield, CA within the 

metropolitan area. It began operating in January 1980. The purpose of the site is to 

monitor representative concentrations of hourly ozone (SLAMS) responses and PM10 

(FRM, SLAMS) every 6 days in an urban area. The site also monitors meteorology. 

During the summer months, high temperatures and longer daylight hours contribute to 

increases in ozone during the day. In contrast, ozone concentrations decrease at night 
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with the absence of sunlight and the presence of NOx pollutants which scavenge the 

ozone. Not only does the metropolitan area generate its own pollution, it is also the 

recipient of pollutants that get transported by wind. On rare occasions, this area of the 

San Joaquin Valley experiences wind events that can carry dust into the area or lift local 

dust particles into the air. Such events can cause PM10 concentrations to increase. 

Shafter 

Shafter, CA is located at the southern end of the San Joaquin Valley with mountains to 

the east and west, and 58 miles to the south. Because the mountains to the south are 

further away, southward air flow is less obstructed through Shafter so pollutant build-up 

is less pronounced compared to Bakersfield and the towns further south. Pollutants 

occur locally and wind can transport pollutants into and through Shafter from nearby 

and upwind areas. The Shafter monitoring site is operated by CARB and is located 18 

miles northwest of the Bakersfield, CA metropolitan area. It began operating in January 

1989. This site was established as a PAMS Type 1 site (SLAMS), located in an area 

upwind of Bakersfield and not to be influenced by upwind or local ozone precursor 

emissions. The site also monitors NO2, NMOC, NMHC, and meteorology. During the 

summer months, high temperatures and longer daylight hours contribute to increases in 

ozone during the day. In contrast, ozone concentrations decrease at night with the 

absence of sunlight and the presence of NOx pollutants which scavenge the ozone. 

Being located upwind of Bakersfield, the Shafter site tends to have lower ozone 

concentrations than does the metropolitan area to the south. 

Stockton-Hazelton 

Stockton, CA is located in the northern part of the San Joaquin Valley with mountains to 

the east and west. North-south air flow is virtually unobstructed. Pollutants occur 

locally but the wind also transports pollutants into the area from upwind locations or 

through the Sacramento Delta from the Bay Area. The Stockton-Hazelton monitoring 

site is operated by CARB and is located in the Stockton, CA metropolitan area. It began 

operating in June 1976. The purpose of the site is to monitor representative 

concentrations of ozone (SLAMS), PM2.5 (BAM and FRM, both SLAMS), and PM10 

(FRM, SLAMS) in an urban area. The site also monitors CO, NO2, toxics, and 

meteorology. During the summer months, high temperatures and longer daylight hours 

contribute to increases in ozone during the day. In contrast, ozone concentrations 

decrease at night with the absence of sunlight and the presence of NOx pollutants 

which scavenge the ozone. During the winter months, ozone concentrations tend to be 

lower due to shorter daylight hours and lower temperatures. Elevated PM2.5 

concentrations are possible year round, but concentrations tend to be highest during the 

winter months due to moisture content in the air, wood burning activities, other 

anthropogenic activities, and atmospheric chemistry. PM2.5 concentrations can also 

increase during wind events because the wind can cause PM2.5 to become suspended 

in the air. On rare occasions, wind will carry dust across the city and cause PM10 

concentrations to increase, but PM10 exceedances are rare. 
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Visalia-Church 

Visalia, CA is located where the central and southern parts of the San Joaquin Valley 

meet. The Sierra Nevada mountain range is approximately 20 miles east of Visalia. 

North-south air flow is virtually unobstructed. Pollutants occur locally and also get 

transported from upwind locations into the area by the wind. The Visalia-Church 

monitoring site is operated by CARB. It began operating in July 1979. The purpose of 

the site is to monitor representative concentrations of hourly ozone (SLAMS), PM2.5 

(BAM and FRM, both SLAMS), and PM10 (FRM, SLAMS) responses from upwind and 

nearby urban areas. The site also monitors NO2 and meteorology. During the summer 

months, high temperatures and longer daylight hours contribute to increases in ozone 

during the day. In contrast, ozone concentrations decrease at night with the absence of 

sunlight and the presence of NOx pollutants which scavenge the ozone. During the 

winter months, ozone concentrations tend to be lower due to shorter daylight hours and 

lower temperatures. Elevated PM2.5 concentrations are possible year round, but 

concentrations tend to be highest during the winter months due to moisture content in 

the air, wood burning activities, other anthropogenic activities, and atmospheric 

chemistry. PM2.5 concentrations can also increase during wind events because the 

wind can cause PM2.5 to become suspended in the air. On rare occasions, wind will 

carry dust across the city and cause PM10 concentrations to increase, but PM10 

exceedances are rare. 

Special Purpose Monitoring Sites

Sequoia-Ash Mountain 

The Ash Mountain monitoring station is operated by Sequoia National Forest and is 

located at the southern entrance of Sequoia National Park at a 1,500-foot elevation. It 

originally began operating in 1985, though the site has been relocated several times 

over the years. The site demonstrates the hourly ozone (SPM) response in the foothills. 

The site also monitors PM2.5 (BAM, SPM) and meteorology. On summer days, ozone 

and precursors can be transported to Ash Mountain from other locations. At this 

location, there are significantly lower hourly emissions of NOx as compared to urban 

areas such as Bakersfield, or Fresno, CA. The amount of available NOx at Ash 

Mountain to scavenge the ozone is much lower. Because the ozone scavenging at Ash 

Mountain is much less than the ozone scavenging in urban areas, Ash Mountain can 

experience elevated ozone concentrations for a 24-hour period during ozone episodes. 

Since the ozone concentration is already fairly high at dawn, only a relatively small 

amount of additional ozone can cause levels in the atmosphere to exceed federal 

standards.

Sequoia-Lower Kaweah 

The Lower Kaweah monitoring station is operated by Sequoia National Forest and is 

located at the southern entrance of Sequoia National Park at a 6,200-foot elevation. It 

began operating in April 1987. The site demonstrates the hourly ozone (SPM) response 

in a rural area. The site also monitors meteorology. On summer days, ozone and 
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precursors can be transported to Ash Mountain from other locations. At this location, 

there are significantly lower hourly emissions of NOx as compared to urban areas such 

as Bakersfield, or Fresno, CA. The amount of available NOx at Lower Kaweah to 

scavenge the ozone is much lower. Because the ozone scavenging at Lower Kaweah 

is much less than the ozone scavenging in urban areas, Lower Kaweah can experience 

elevated ozone concentrations for a 24-hour period during ozone episodes. Since the 

ozone concentration is already fairly high at dawn, only a relatively small amount of 

additional ozone can cause levels in the atmosphere to exceed federal standards. 

Other Sites

Santa Rosa Rancheria

Santa Rosa Rancheria is Tribal land located in the central portion of the San Joaquin 

Valley in Lemoore, CA. It is 13 miles southwest of Hanford, CA and 39 miles south of 

the Fresno, CA metropolitan area. The Diablo Mountain Range is approximately 27 

miles east of Santa Rosa Rancheria. North-south air flow is virtually unobstructed. 

Pollutants occur locally and wind transports pollutants into and through the site from 

nearby and upwind urban areas as well. The Santa Rosa Rancheria monitoring site is 

operated by the Tachi-Yokut tribe. It began operating in August 2006. The purpose of 

the site is to monitor representative concentrations of hourly ozone (SPM) and PM10 

responses from upwind and nearby urban areas. During the summer months, high 

temperatures and longer daylight hours contribute to increases in ozone during the day. 

In contrast, ozone concentrations decrease at night with the absence of sunlight and the 

presence of NOx pollutants which scavenge the ozone. On rare occasions, this area of 

the San Joaquin Valley experiences wind events that can carry dust into the area or lift 

local dust particles into the air. Such events can cause PM10 concentrations to 

increase. 
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