San Joaquin Valley Unified Air Pollution Control District June 30, 2010

San Joaquin Valley Air Pollution Control District 

Air Monitoring Network Plan 

June 30, 2010 

For Submittal to the U.S. Environmental Protection Agency in July 2010 

 
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

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, 2010

Table of Contents

The District’s Core Values and Air Monitoring Requirements.....................1 

Executive Summary....................................................................................3 

Introduction: What’s required in the monitoring network plan ....................4 

What an Air Monitor Represents ................................................................6 

Ozone ......................................................................................................12 

PAMS ............................................................................................13 

Particulate Matter ....................................................................................17 

PM Collocation Requirements .......................................................27 

Public Review of Changes to the PM2.5 Monitoring Network ......28 

Carbon Monoxide ....................................................................................28 

Nitrogen Dioxide ......................................................................................29 

Sulfur Dioxide ..........................................................................................30 

Lead ........................................................................................................30 

Toxics ......................................................................................................31 

Green House Gases.................................................................................31 

Meteorology .............................................................................................31 

NCore .......................................................................................................32 

Five-Year Monitoring Network Assessment..............................................34 

Summary of monitoring changes, January 2009 – July 2010 ..................37 

Summary of changes planned, July 2010 – December 2011 ..................38 

Data Submission Requirements ...............................................................40 

Acronyms, Abbreviations, Initialisms ........................................................41 

Appendix A: Monitoring Site Descriptions 

Appendix B: Detailed SJV Monitoring Site Information 

Appendix C: STI 5-year Network Assessment 

2010 Air Monitoring Network Plan 

 

 

i
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Tables

Table 1 SJV Areas of Representation ....................................................5 

Table 2 SJV 2009 Population .................................................................6 

Table 3 Ambient Air Monitoring Sites in the SJVAB ...............................8 

Table 4 SLAMS Minimum Ozone Monitoring Requirements ................13 

Table 5 Ozone Requirements for the San Joaquin Valley ....................14 

Table 6 San Joaquin Valley Ozone Monitors, SLAMS and SPM...........15 

Table 7 SJV PAMS sites .......................................................................17 

Table 8 Minimum PM10 Monitoring Requirements ...............................19 

Table 9 Minimum PM2.5 Monitoring Requirements ..............................19 

Table 10 PM Monitoring Requirements and SLAMS monitors 

 for the Valley ...........................................................................20 

Table 11 PM SLAMS monitors in the Valley ..........................................21 

Table 12 PM SPM monitors in the Valley ................................................26 

Table 13 Carbon Monoxide Monitoring Stations in the SJV ...................28 

Table 14 NO2 Monitoring Stations in the San Joaquin Valley ................29 

Table 15 SO2 Monitoring Station in the San Joaquin Valley ..................30 

Table 16 Meteorology Monitoring Stations in the SJV ............................33 

Figures

Figure 1 Map of Air Monitoring Sites in the San Joaquin Valley ..............2

2010 Air Monitoring Network Plan 

 

 

ii
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

2010 Air Monitoring Network Plan 

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.

 

1
 Valley Unified Air Pollution Control District June 30, 2010

2010 Air Monitoring Network Plan 2

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

San Joaquin
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Executive Summary

The San Joaquin Valley Air Pollution Control District (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. Through their appearance on the District 

website, in Valley media, and as school air quality flags, the AQI 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 make sure 

these activities do not make air quality unhealthy. 

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

samples that are rigorously analyzed by laboratory technicians and District staff. This 

data determines the Valley’s attainment status for the U.S. Environmental Protection 

Agency’s (EPA) health-based air quality standards. This data is also 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. These 

monitoring data are 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. 

2010 Air Monitoring Network Plan 

 

3
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Introduction: What’s required in this monitoring network plan

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 healthbased 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 (ARB) 

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. 

STN Speciated Trends Network PM2.5 speciation stations that provide 

chemical speciation data of PM 

2010 Air Monitoring Network Plan 

 

4
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

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)): 

• AQS (air quality system) site identification number 

• Locations: street address and geographical coordinates 

• 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 

• 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 

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 

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 1 12540 

Fresno 23420 

Hanford-Corcoran 25260 

Madera 31460 

Merced 32900 

Modesto 33700 

Stockton 44700 

Visalia - Porterville 47300 

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 San Joaquin Valley Air District 

and the Kern County Air Pollution Control District are 

counted in determining compliance with minimum 

monitoring requirements for the Bakersfield MSA. 

2010 Air Monitoring Network Plan 

 

5
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

or the creation/change to a community monitoring zone. This should include 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. 

Agencies should submit any public comments received from PM2.5 monitoring changes 

in the submittal of the network plan. 

In addition, a network assessment must be completed every five years to demonstrate 

that the monitoring network meets monitoring objectives, whether any sites are no 

longer needed, whether new technologies might be appropriate. The first assessment 

is due July 1, 2010. The District engaged a consultant to complete this analysis, which 

was finalized in the fall of 2009 (this analysis is attached as Appendix C). This 

comprehensive review is reflected in the 2010 Monitoring Network Plan. 

Table 2 SJV 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 

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 

Kern (Valley Portion) 686,967 Bakersfield Delano 

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 1/1/2009. 

What an Air Monitor Represents

Each air monitor is sited to satisfy at least one of three specific objectives, represent 

generally consistent pollution concentrations, and represent a specific geographic scale. 

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) 

2010 Air Monitoring Network Plan 

 

6
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

2010 Air Monitoring Network Plan 

 

7

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 

• 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. 

Table 3 summarizes all the ambient air monitoring sites in the San Joaquin Valley Air 

Basin. It should be noted that in addition to the monitoring sites discussed in this 

monitoring network plan, ARB operates two special purpose monitors in the Valley, Lodi 

East and Lodi West. 

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 San Joaquin Valley Air District balances a wide range of pollutant siting 

criteria, spatial scales, monitoring objectives, and practical concerns as it plans and 

operates its monitoring network. 
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Table 3 Ambient Air Monitoring Sites in the San Joaquin Valley Air Basin (Summ

As of June 1, 2010 

MSA, 

County Site Name AIRS Agency Address Pollutants M

Ozone, PM10 FRM, PM2.5 BANMOC (PAMS), wind speed, wtemperature, relative humidity, radiation 

SJV Clovis-N Villa 

Avenue

908 N. Villa Av, Clovis CA 

60195001 APCD 93612 

SJV Fresno - 

Drummond Street

4706 E. Drummond Street, Fresno CA 93725 

Ozone, PM10 FRM, CO, NO2, 

60190007 APCD outdoor temperature, barometr

Ozone, PM10 FRM, PM10 BAMBAM, CO, NO2, SO2, toxics, woutdoor temperature, relative hpressure 

Fresno - First Street

3425 N. First St, Fresno CA 

60190008 ARB 93726 

SJV 

Fresno - Pacific 60195025 APCD 

1716 Winery, Fresno CA 93726 PM2.5 FRM 

Fresno, 

Fresno 

SJV 4508 Chennault Ave, Fresno 

CA 93722 

Ozone, CO, NO2, wind speed, 

Fresno - Skypark 60190242 APCD temperature Huron 60192008 SJVAPCD 

16875 4th Street, Huron, CA 

93234 PM2.5 BAM, barometric pressu

Parlier Ozone, NO2, NMOC (PAMS), 

direction, outdoor temperature, 

60194001 SJVAPCD barometric pressure, solar radi

9240 S. Riverbend Av, Parlier CA 93648 

Tranquillity 60192009 SJVAPCD 

32650 West Adams, Tranquillity CA 93668 

Ozone, PM2.5 BAM FEM, wind outdoor temperature, barometr

Ozone, NO2, NMOC (PAMS), direction, outdoor temperature, 

Arvin 60295001 barometric pressure, solar radi

SJVAPCD and ARB 

20401 Bear Mountain Blvd, Arvin CA 93203 

Bakersfield, 

Kern 

Bakersfield - Airport

401 E. Planz Rd., 

 - Planz 60290016 ARB Bakersfield CA 93307 PM2.5 FRM 

2010 Air Monitoring Network Plan 8
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

MSA, Site Name AIRS Agency Address Pollutants M

County 

Ozone, PM10 FRM, PM10 BAMoperated by the SJVAPCD), PMBAM/FEM, NO2, toxics, wind soutdoor temperature, relative hpressure, solar radiation 

BakersfieldCalifornia Avenue 5558 California, Bakersfield 60290014 ARB CA 93309 

Ozone, PM10 TEOM, PM2.5 B(PAMS), NMHC, wind speed, wtemperature, relative humidity, 

Bakersfield-Muni radiation 1 SJVAPCD 

Johnson Farm-Shed Rd, Edison CA 93320 

Ozone, NO2, wind speed, wind 

Edison 60290007 ARB temperature 

PM2.5 BAM, wind speed, wind temperature, relative humidity, 

Lebec 60292009 SJVAPCD radiation 

Beartrap Road (no #), Lebec, CA 91350 

755 Stanislaus Street, Maricopa CA 93352 

Ozone, wind speed, wind direc

Maricopa 60290008 SJVAPCD barometric pressure 

3311 Manor St, Oildale CA 93308 

Ozone, PM10 FRM, wind spee

Oildale 60290232 ARB temperature Shafter Ozone, NO2, NMOC (PAMS), 

direction, outdoor temperature, 

60296001 barometric pressure, solar radi

SJVAPCD and ARB 

578 Walker St, Shafter CA 93263 

CorcoranPatterson Avenue

PM10 FRM, PM10 TEOM, PM2wind speed, wind direction, out

60310004 SJVAPCD barometric pressure 

1520 Patterson Av, Corcoran CA 93212 

Hanford-S Irwin Street 60311004 SJVAPCD 

807 S Irwin St, Hanford CA 93230 

Ozone, PM10 FRM, PM2.5 BAwind direction, outdoor tempera

Hanford – 

Corcoran, 

Kings 

Santa Rosa Rancheria 60310500 Tachi-Yokut Ozone, PM10, meteorology 

Ozone, PM10 TEOM, PM2.5 Bdirection, outdoor temperature, relative humidity, solar radiatio

Madera, 

Madera 28261 Avenue 14, Madera, Madera – City 60392010 SJVAPCD CA 93638 

2010 Air Monitoring Network Plan 9
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

MSA, Site Name AIRS Agency Address Pollutants M

County 

Ozone, NO2, NMOC (PAMS), direction, outdoor temperature, barometric pressure, solar radi

Madera - Pump Yard

Av 8 and Road 29 1/2, 

60390004 SJVAPCD Madera CA 93637 

Merced - Coffee Road

385 S. Coffee St., Merced CA 95340 

Ozone, PM2.5 BAM/FEM, NO2

Merced, 60470003 SJVAPCD direction, outdoor temperature, 

Merced 2334 M Street, Merced CA 

Merced M Street 60472510 SJVAPCD 95340 PM10 FRM, PM2.5 FRM 

Ozone, PM10 FRM, PM2.5 FRtoxics, wind speed, wind directrelative humidity 

StocktonHazelton 1593 E Hazelton St, 60771002 ARB Stockton CA 95205 StocktonWagner-Holt School 60773010 SJVAPCD 

8778 Brattle Pl, Stockton CA 95209 PM10 FRM 

Stockton, 

San 

Joaquin 

Ozone, PM10 TEOM, PM2.5 Bwind direction, outdoor temperaradio acoustic sounding system 

5749 S. Tracy Blvd., Tracy 

Tracy-Airport 60773005 SJVAPCD CA 95376 

Ozone, PM10 FRM, PM2.5 FRspeed, wind direction, outdoor pressure 

Modesto-14th Street

814 14th Street, Modesto CA 

Modesto, 60990005 ARB 95354 

Stanislaus Ozone, PM10 FRM, PM2.5 BA

speed, wind direction, outdoor pressure 

1034 S Minaret St, Turlock 

Turlock 60990006 SJVAPCD CA 95380 Porterville 61072010 SJVAPCD 

1839 S Newcomb Street, Porterville, CA 93257 

Ozone, PM2.5 BAM, wind speetemperature, barometric pressu

Visalia – 

Porterville, 

Tulare National 

Park Service (NPS)

Ozone, PM2.5 FRM, PM2.5 BAdirection, outdoor temperature, radiation 

Sequoia -Ash Mountain

Ash Mountain, Sequoia 

61070009 National Park CA 

2010 Air Monitoring Network Plan 10
 Valley Unified Air Pollution Control District June 30, 2010

2010 Air Monitoring Network Plan 11

MSA, 

County Site Name AIRS Agency Address Pollutants M

Sequoia -Lower Kaweah 61070006 

National Park Service (NPS)

Lower Kaweah Campground, Sequoia National Park, CA 

Ozone, wind speed, wind direcrelative humidity, solar radiatio

Visalia-Airport 61073000 SJVAPCD Airport, Visalia CA 93291 

wind speed, wind direction, outhumidity, barometric pressure, acoustic sounding system (RAS

Ozone, PM10 FRM, PM2.5 FRspeed, wind direction, outdoor 

Visalia - Church 61072002 ARB pressure 

310 N. Church St, Visalia CA 93291 

1 Bakersfield – Golden (AIRS 60290010) was shut down for relocation in December 2009. The replacement site, Bakersfie

reporting data in October 2010.

San Joaquin
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

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. 

Ozone formation and transport has been studied in the Valley for many years. One of 

the more recent efforts has been the Central California Ozone Study (CCOS), which 

includes most of northern California and all of central California. CCOS monitoring was 

conducted during the summer of 2000. Emission inventory development, data analysis, 

and modeling are complete. New tools and assessments, such as cluster analysis, are 

being conducted to gain further value from the developments of CCOS. The District 

expects that the final CCOS analysis will by synthesized into a report in 2012 to update 

the conceptual understanding of ozone. CCOS work is directed by the Policy and 

Technical Committees, comprised of representatives from federal agencies, ARB, the 

California Energy Commission, local air pollution agencies, researchers, and industry 

and sponsoring organizations. CCOS results have been used in the development of 

attainment plans, such as the District’s 2007 Ozone Plan and for the improvement of 

forecasting tools, which are used on a daily basis. 

More recently, the District has been involved in CalNex 2010, which is a major climate 

and air quality field study in California conducted by the National Oceanic and 

Atmospheric Administration (NOAA) and the California Air Resources Board (ARB), with 

the participation of numerous academic researchers. It will occur in May and June of 

2010. NOAA’s deployment of two aircraft in the state for 4 to 6 weeks will generate a 

dataset of unprecedented chemical completeness, spatial extent and temporal 

resolution. The presence of the research vessel Atlantis will provide data about the 

emissions and impacts of shipping off California’s coast. The study will answer 

important scientific questions about emissions, chemical transformations, climate 

processes, transport, and meteorology in California. The air quality and meteorological 

data collected during CalNex will improve ARB’s emission inventories of greenhouse 

gases, traditional air pollutants and precursors. In addition the study would improve 

ARB’s air quality models used in SIP development and our understanding of the 

atmospheric formation of ozone and PM. 

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. Ozone monitoring site requirements are based on MSA population and 

on design values based on MSA, as shown in Table 4. Table 5 shows that the Valley’s 

ozone network meets the requirements of Table 4. Sites are intended to represent 

population exposures and maximum concentrations, so most ozone monitors are 

2010 Air Monitoring Network Plan 

 

12
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

represent neighborhood or urban scale measurements. Table 6 shows the Valley’s 

ozone monitoring sites. 

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 

• 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) 

The District has a total of six PAMS sites configured as two small networks, one 

centered on Fresno and one on Bakersfield (see Table 7). 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 4 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 Most recent 3-year design 

value concentrations value concentrations 

≥85% of any ozone <85% of any ozone 

NAAQS NAAQS 

> 10 million 4 2 

4 – 10 million 3 1 

350,000 – < 4 million 2 1 

50,000 – < 350,000 1 0 

2010 Air Monitoring Network Plan 

 

13
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

2010 Air Monitoring Network Plan 

 

14

Table 5 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 4) 

Number 

of active 

SLAMS 

ozone 

monitor 

sites 

Bakersfield 827,173 2 105 Yes 2 7 2, 3 

Fresno 942,298 100 Yes 2 6 

HanfordCorcoran 154,743 87 Yes 1 1

Madera 152,331 84 Yes 1 2 

Merced 256,450 89 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. 

3

 Includes the not yet operational Bakersfield-Muni air monitoring site. 
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Table 6 San Joaquin Valley Ozone Monitors, SLAMS and SPM 

As of June 1, 2010 

MSA County Site AIRS Code Agency Scale 

Site Type 

SLAMS

Clovis 60195001 SJVAPCD Neighborhood Population Fresno – Drummond 60190007 SJVAPCD Neighborhood Population, Region

transport 

Fresno – First 60190008 ARB Neighborhood Population Fresno – Skypark 60190242 SJVAPCD Neighborhood Population, Region

transport 

Fresno Fresno 

Parlier 60194001 ARB Neighborhood High Concentration

Regional transport 

60295001 ARB and Neighborhood High Concentration

Arvin Regional transport SJVAPCD Bakersfield – California 60290014 ARB Neighborhood Population Bakersfield – Muni2 60290010 SJVAPCD Neighborhood Population 

60290007 Neighborhood High concentration, 

regional transport Bakersfield Kern Edison ARB 

Maricopa 60290008 SJVAPCD Neighborhood regional transport Oildale 60290232 ARB Neighborhood regional transport 

60296001 ARB and Neighborhood General/backgroun

Shafter 

SJVAPCD 

HanfordCorcoran 60311004 Neighborhood Population Kings Hanford 1 SJVAPCD 

Madera – Pump Yard 60390004 SJVAPCD Neighborhood General/backgroun

Madera Madera 

Madera City 60392010 SJVAPCD Neighborhood Population 

2010 Air Monitoring Network Plan 15
 Valley Unified Air Pollution Control District June 30, 2010

2010 Air Monitoring Network Plan 16

MSA County Site AIRS Code Agency Scale Site Type 

Merced Merced Merced – Coffee 60472510 SJVAPCD Neighborhood Population 

Stockton – Hazelton 60771002 ARB Neighborhood Population Stockton San Joaquin Tracy - Airport 60773005 SJVAPCD Neighborhood Regional transport Modesto – 14th 60990005 ARB Neighborhood Population Modesto Stanislaus 

Turlock 60990006 SJVAPCD Neighborhood Population 

Visalia - Visalia – Church 61072002 ARB Neighborhood Population 

Porterville Tulare Porterville 61072010 SJVAPCD Neighborhood Population 

SPM

Fresno Fresno Tranquillity 60192009 SJVAPCD Urban Scale Population 

HanfordCorcoran Kings Santa Rosa Rancheria 60310500 Tachi-Yokut Tribe 

Ash Mountain – Sequoia National Park 

61070009 NPS Regional Regional transport 

Visalia - 

Porterville Tulare Lower Kaweah – 

Sequoia National Park 

61070006 NPS Regional Regional transport 

1 Shutdown of the Corcoran ozone monitor occurred in November 2009. The monitor was reinstalled at reconstructed Han

February 2010. During the months in between, the monitor was serviced, calibrated and tested. 2 Bakersfield – Golden was shut down for relocation in December 2009. The replacement site, Bakersfield-Muni, will begin 

October 2010. 

San Joaquin
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Table 7 SJV PAMS sites 

As of June 1, 2010 

Type 1: Upwind/Background site Madera-Pump Yard 

Type 2: Maximum precursor 

emissions 

Clovis-Villa 

Fresno MSA 

Type 3: Maximum ozone 

concentrations 

Parlier 

Type 1: Upwind/Background site Shafter-Walker 

Bakersfield-Muni 1 Type 2: Maximum precursor 

emissions Bakersfield 

MSA 

Type 3: Maximum ozone 

concentrations 

Arvin 

1 Bakersfield – Golden was shut down for relocation in December 2009. The replacement site, 

Bakersfield-Muni, will begin reporting data in October 2010. 

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. State and 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 San Joaquin Valley is 

designated nonattainment for PM2.5. 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 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 

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

2010 Air Monitoring Network Plan 

 

17
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

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

Air Quality Study (CRPAQS). CRPAQS monitoring occurred between December 1999 

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 PM monitoring network includes Federal Reference Method (FRM) 

monitors, Federal Equivalent Method (FEM) monitors, Beta Attenuation Monitors (BAM), 

and Tapered Element Oscillating Microbalance (TEOM). FRM monitors for PM are 

manual filter-based monitors; samples are collected on an either 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. 

BAMs and TEOMs are continuous, near real-time monitors that provide the hourly PM 

data used in AQI and Smoke Management System (SMS) forecasting. Data from these 

monitors are also reporting 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. 

Table 8 shows the minimum number of PM10 sites required per MSA, and Table 9 

shows the minimum number of PM2.5 sites required per MSA. Table 10 applies the 

requirements of Tables 8 and 9 to the Valley. Tables 11 and 12 summarize the Valley’s 

SLAMS and SPM PM monitoring stations, respectively. 

2010 Air Monitoring Network Plan 

 

18
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

2010 Air Monitoring Network Plan 

 

19

Table 8 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 9 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 
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Table 10 PM Monitoring Requirements and SLAMS monitors for the Valley 

PM10 PM2.5 

Metropolitan 

Statistical 

Area (MSA) 

County 2009 Population

24-hour 2009 Highest concentration in MSA (μg/m3) 1 

Monitors required 

Actual # of primary SLAMS sites in MSA 

24-hour 2007-2009 Design Value in MSA (μg/m3) 1 

Annual 2007-2009 Design Value in MSA (μg/m3) 

Moreq

Bakersfield Kern 827,173 2 138 2 – 4 3 * 76 21.5 

Fresno Fresno 942,298 84 1 – 2 3 58 16.3 

Hanford- 

Corcoran 

154,743 121 0 – 1 2 51 17.2 

Kings 

Madera Madera 152,331 - 0 1 - - 

Merced Merced 256,450 64 0 1 48 14.1 

Modesto Stanislaus 526,383 65 1 – 2 2 54 14.0 

San 

Joaquin 

689,480 61 1 – 2 3 45 12.2 

Stockton 

Visalia - 

Porterville 

441,481 92 0 - 1 1 57 18.2 

Tulare 

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

requirements. 2 The population listed for Bakersfield here reflects the population for all of Kern County, not just the Valley portion. Air mo

Eastern Kern Air District would count towards the monitors required for the Bakersfield MSA. However, the “Actual # of mo

listed here includes those in the San Joaquin Valley Air Basin only. 3 The Manteca site is tentatively scheduled to begin operating in October 2010 to meet this requirement. 

* Includes the forthcoming Bakersfield-Muni site. 

2010 Air Monitoring Network Plan 20
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Table 11 PM SLAMS monitors in the Valley 

As of June 1, 2010 

Size Fraction MSA, 

County Site AIRS Code Agency Scale Site Type Monitoring Objective PM10 

PM2.5 

Standards/ Xstrategy, research support 

Fresno Pacific – Winery 

60195025 SJVAPCD Neighborhood Population 

Standards/ strategy, research support 

X 

Fresno Drummond 60190007 SJVAPCD Neighborhood Population 

Standards/ strategy, research support 

X 

Timely/public X Timely/public X 

Fresno, Fresno 

Fresno – First Street 

High 

Concentration 60190008 ARB Neighborhood

Standards/ strategy, research support 

X 

Standards/ strategy, research support 

X 

Clovis - Villa 60195001 SJVAPCD Neighborhood Population 

Timely/public X 

2010 Air Monitoring Network Plan 21
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Size Fraction MSA, 

County Site AIRS Code Agency Scale Site Type Monitoring Objective PM10 

PM2.5 

Standards/ strategy, research support 

X 

Oildale 60290232 ARB Neighborhood Population 

Standards/ strategy, research support 

X 

Timely/public X Timely/public X 

Bakersfield – California Ave 

60290014 ARB Neighborhood Population 

Standards/ strategy, research support 

X 

Bakersfield,

Kern 

Timely/public X 

High 

Concentration 

Bakersfield – Muni1 pending SJVAPCD Neighborhood Timely/public X 

Standards/ strategy, research support 

X 

Bakersfield – Planz 60290016 ARB Neighborhood Population 

Standards/ strategy, research support 

X 

Hanford/ Corcoran, Kings 

Hanford 60311004 SJVAPCD Neighborhood Population 

2010 Air Monitoring Network Plan 22
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Size Fraction MSA, 

County Site AIRS Code Agency Scale Site Type Monitoring Objective PM10 

PM2.5 

Timely/public X Standards/ strategy, research support 

X, X collocated 

Standards/ strategy, research support 

X 

Corcoran –Patterson 

High 

Concentration 60310004 SJVAPCD Neighborhood

Timely/public X 

Madera, Madera 

MaderaCity Timely/public X 

60392010 SJVAPCD Neighborhood Population 

Standards/ strategy, research support 

X 

Merced, Merced 

Merced – M Street 

Representative

concentration 60472510 SJVAPCD Neighborhood Standards/ 

strategy, research support 

X 

Standards/ strategy, research support 

X 

Stockton, San Joaquin 

Stockton Hazelton 60771002 ARB Neighborhood Population 

Timely/public X 

2010 Air Monitoring Network Plan 23
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Size Fraction MSA, 

County Site AIRS Code Agency Scale Site Type Monitoring Objective PM10 

PM2.5 

Standards/ strategy, research support 

X 

Standards/ strategy, research support 

X 

Stockton – Wagner – Holt 

60773010 SJVAPCD Neighborhood Population 

Tracy – Airport 

Regional Timely/public X 

transport 60773005 SJVAPCD Neighborhood

Standards/ strategy, research support 

X 

Timely/public X 

Modesto – 14th 60990005 ARB Neighborhood Population 

Standards/ strategy, research support 

X 

Modesto, Stanislaus 

Standards/ strategy, research support 

X 

Turlock 60990006 SJVAPCD Neighborhood Population 

Timely/public X Standards/ strategy, research support 

X 

Visalia -Porterville,

Tulare 

Visalia - Church 61072002 ARB Neighborhood Population 

2010 Air Monitoring Network Plan 24
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Size Fraction MSA, 

County Site AIRS Code Agency Scale Site Type Monitoring Objective PM10 

PM2.5 

Timely/public X Standards/ strategy, research support 

X 

1 Bakersfield – Golden was shut down for relocation in December 2009. The replacement site, Bakersfield-Muni, will 

October 2010. 

2010 Air Monitoring Network Plan 25
 Valley Unified Air Pollution Control District June 30, 2010

2010 Air Monitoring Network Plan 26

Table 12 PM SPM monitors in the Valley 

As of June 1, 2010 

Size Fraction MSA, 

County Site AIRS Code Agency Scale Site Type Monitoring Objective PM10 PM2.5 

Huron 60192008 SJVAPCD Neighborhood Population Timely/public X 

Fresno, 

Fresno 

Tranquillity 60190009 SJVAPCD Urban Urban Timely/public X 

BakersfieldMuni 1 60290010 SJVAPCD Neighborhood High Concentration Timely/public X 

Bakersfield, 

Kern 

Lebec 60292009 SJVAPCD Neighborhood Population Timely/public X 

X 

Hanford/ 

Corcoran, 

Kings 

Hanford 60311004 SJVAPCD Neighborhood Population Timely/public 

X 

Madera, 

Madera Madera-City 60392010 SJVAPCD Neighborhood Population Timely/public X 

Merced, 

Merced 

MercedCoffee 60470003 SJVAPCD Neighborhood Population Timely/public X 

Stockton, 

San Joaquin Tracy-Airport 60773005 SJVAPCD Neighborhood Regional transport Timely/public X 

Research support X 

Ash Mountain 61070009 National Park Service Regional Regional transport Timely/public X 

Visalia - Porterville, 

Tulare 

Porterville 61072010 SJVAPCD Neighborhood Population Timely/public X 

1 Bakersfield – Golden was shut down for relocation in December 2009. The replacement site, Bakersfield-Muni, will begin 

October 2010.

San Joaquin
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

PM Collocation Requirements 

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

Monitors are said to be collocated if these monitors are at the same monitoring site, 

measure the same pollutant, and are the same type of instrument. Monitors are said to 

be parallel when these monitors are at the same monitoring site and measure the same 

pollutant but use different types of instruments (such as an FRM paired with a BAM). 

Monitors that measure the same pollutant with the same technique but at different 

monitoring sites are also said to be parallel. Collocation requirements are based on a 

“primary quality assurance organization” (PQAO), not on individual air basis. ARB is the 

PQAO for the Valley as well as several other air basins, so ARB must meet collocation 

requirements for the PQAO as a whole. 

In a network of manual PM10 FRMs, 15% of the monitors should have collocated 

sampling, with at least one collocated pair. These collocated monitors should be at 

sites recording annual PM10 concentrations in the highest 25% of all sites in the 

network, or at EPA-selected sites. 

If an area is using PM10-2.5 FEMs, then the Regional EPA Administrator will select the 

sites for collocated PM10 monitoring. An area should have 15% of its FEM PM10-2.5 

monitors collocated, with at least 2 collocated pairs. With 2 collocated pairs, one should 

be two FRM monitors, and the other pair should be two FEM monitors (and these pairs 

can be at the same monitoring site). The District currently does not have any monitors 

in the PM10-2.5 size range, and none are required. 

 

EPA’s PM2.5 monitoring collocation requirements indicate that 15% of all FRM or FEM 

monitors in an area must be collocated, with at least 1 collocated pair. For each 

collocated pair, one PM2.5 sampler is designated as the primary monitor for air quality 

reporting, and the other PM2.5 monitor is an audit monitor. All primary collocated 

monitors using FRM monitoring just be collocated with FRM audit monitors. Of all the 

primary collocated monitors using FEM monitoring, half must collocated with an FEM 

audit monitor, and half must be paired with an FRM parallel audit monitor. If there is an 

odd number of FEM primary monitors, then the additional monitor should be paired with 

an FRM audit monitor. 

Of all the collocated PM2.5 monitoring sites, 80% should be sites with annual average 

or daily PM2.5 concentrations within a range of ±20% of the NAAQS. So ideally, 80% 

of the collocated PM2.5 sites would be recording annual averages between 12 μg/m3 

and 18 μg/m3 and daily PM2.5 concentrations between 28 μg/m3 and 42 μg/m3. 

However, if an area does not have enough sites that meet these criteria, then 60% of 

the collocated audit monitors should be at the sites with the highest PM2.5 

concentrations (within the top 25% for the area). 

2010 Air Monitoring Network Plan 

 

27
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Public Review of Changes to the PM2.5 Monitoring Network 

The District is required to seek public input whenever proposing 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 comment from the public of 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 in the District website, and 

public notice is published in a newspaper of general circulation in each affected CBSA. 

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

Monitoring has shown that the Valley’s CO concentrations have not exceeded the 

NAAQS for over a decade. As noted in section 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. The District has added a trace-level CO analyzer at Clovis and a 

trace level CO monitor to the Bakersfield-Golden site. Table 13 summarizes the 

Valley’s CO monitoring sites. 

Table 13 Carbon Monoxide Monitoring Stations in the San Joaquin Valley 

As of June 1, 2010 

Site Name Sampling AIRS Scale Site Type Objective Agency Frequency 

Standards/ 

Strategy 

SJV 

APCD 

BakersfieldMuni1 060290010 Continuous Neighborhood Population 

Standards/ 

Strategy 

SJV 

APCD Clovis – Villa 060175001 Continuous Neighborhood Population 

Fresno – 

Drummond 

Standards/ 

Strategy 

SJV 

APCD 060190007 Continuous Neighborhood Population 

Standards/ 

Strategy Fresno – 1st 060190008 Continuous Neighborhood Population ARB 

Fresno – Sky 

Park 

Standards/ 

Strategy 

SJV 

APCD 060190242 Continuous Neighborhood Population 

Standards/ 

Strategy 

Modesto – 

14th Street 060990005 Continuous Neighborhood Population ARB 

Stockton – 

Hazelton 

Standards/ 

Strategy 060771002 Continuous Neighborhood Population ARB 

Standards/ 

Strategy 

SJV 

APCD 

Turlock - 

Minaret 060990006 Continuous Neighborhood Population 

1

 Bakersfield – Golden was shut down for relocation in December 2009. The replacement site, 

Bakersfield-Muni, will begin reporting data in October 2010. 

2010 Air Monitoring Network Plan 

 

28
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Nitrogen Dioxide

As noted in section 4.3 of Appendix D of 40 CFR Part 58, there are no minimum 

requirements of the number of NO2 monitoring sites. Although the Valley does not 

exceed federal or state standards for NO2, NOx reductions contribute to air quality 

improvement for both ozone and PM. NO/NOy measurements are collected at both the 

NCore multipollutant and PAMS sites to improve understanding of ozone 

photochemistry. Table 14 summarizes the Valley’s NO2 monitoring sites. 

On January 22, 2010, EPA strengthened the health-based NAAQS for NO2, setting a 

new 1-hour NO2 standard at the level of 100 parts per billion (ppb). The monitoring 

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

the annual average daily traffic (AADT) count. Monitors are to be placed close to major 

roadways with the highest AADT counts. NO2 monitors that are required under this new 

standard are to be operational by January 1, 2013. These requirements will be 

addressed in the 2011 Annual Monitoring Network Plan. 

Table 14 NO2 Monitoring Stations in the San Joaquin Valley 

As of June 1, 2010 

Site Name Sampling AIRS Scale Site Type Objective Agency Frequency 

Arvin 060295001 Continuous Neighborhood Population 

Standards/ 

Strategy, 

Research 

ARB 

Bakersfield 

– California 

Standards/ 

Strategy, 060290014 Continuous Neighborhood Population ARB 

Standards/ 

Strategy, 

Research 

SJV 

APCD 

High 

Concentration 

BakersfieldMuni 1 060290010 Continuous Neighborhood 

Standards/ 

Strategy, 

Research 

SJV 

APCD 

High 

Concentration 

Clovis – 

Villa 060175001 Continuous Neighborhood 

Edison – 

Johnson 

Ranch 

Standards/ 

Strategy 060290007 Continuous Neighborhood Population ARB 

High 

Concentration 

Standards/ 

Strategy 

SJV 

APCD 

Fresno – 

Drummond 060190007 Continuous Neighborhood 

Standards/ 

Strategy Fresno – 1st 060190008 Continuous Neighborhood Population ARB 

Fresno – 

Sky Park 

Standards/ 

Strategy 

SJV 

APCD 060190242 Continuous Neighborhood Population 

Hanford 060311004 Continuous Neighborhood Population Standards/ 

Strategy 

SJV 

APCD 

Standards/ 

Strategy, Madera – 060390004 Continuous Neighborhood Population SJV 

2010 Air Monitoring Network Plan 

 

29
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Pump Yard Research APCD 

Merced – 

Coffee 

Standards/ 

Strategy 

SJV 

APCD 060470003 Continuous Neighborhood Population 

Parlier 060194001 Continuous Neighborhood Population 

Standards/ 

Strategy, 

Research 

SJV 

APCD 

Shafter – 

Walker 

Street 

Standards/ 

Strategy, 

Research 

060296001 Continuous Neighborhood Population ARB 

Standards/ 

Strategy 

Stockton – 

Hazelton 060771002 Continuous Neighborhood Population ARB 

Standards/ 

Strategy 

SJV 

APCD 

Tracy – 

Airport 060773005 Continuous Neighborhood Population 

Turlock - 

Minaret 

Standards/ 

Strategy 

SJV 

APCD 060990006 Continuous Neighborhood Population 

Visalia - 

Church 

Standards/ 

Strategy 061072002 Continuous Neighborhood Population ARB 

1 Bakersfield – Golden was shut down for relocation in December 2009. The replacement site, 

Bakersfield-Muni, will begin reporting data in October 2010. 

Sulfur Dioxide

Section 4.4 of Appendix D of 40 CFR Part 58 notes that there are no minimum 

requirements of the number of SO2 monitoring sites. The Valley does not exceed 

federal or state standards for SO2. There is just one SO2 monitoring site in the Valley, 

shown in Table 15. 

Table 15 SO2 Monitoring Station in the San Joaquin Valley 

As of June 1, 2010 

Site Name Sampling AIRS Scale Site Type Objective Agency Frequency

Standards/ 

Strategy Fresno – 1st 060190008 Continuous Neighborhood Population ARB 

Lead

EPA revised the lead (Pb) NAAQS and monitoring requirements in the Federal Register 

on November 12, 2008 (73 FR 66964 – 67062, codified in 40 CFR 58.10). This would 

have required the District to install non-source oriented Pb monitors by January 1, 2011 

in CBSAs that exceed a population of 500,000: the Stockton, Modesto, Fresno, and 

Bakersfield. However, in response to a petition for reconsideration, EPA proposed 

changes to the lead monitoring requirements in December 2009 (74 FR 69050-69059). 

2010 Air Monitoring Network Plan 

 

30
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

EPA has proposed replacing the 500,000-population-CBSA requirement with an 

approach utilizing NCore sites. The District has thus suspended its previous lead 

monitoring plans. Once the proposed NCore-based lead monitoring approach is 

approved, EPA expects to require monitoring agencies to commence lead sampling at 

NCore sites no later than January 1, 2011. ARB would then be required to begin 

operating a lead monitor at the Fresno-First NCore site by January 2011. 

Also, EPA is proposing to change the source-oriented lead monitoring requirements, 

lowering the threshold from 1.0 tons per year (tpy) to 0.5 tpy. The Valley has no 

sources at the 1.0 tpy threshold. EPA documentation suggested that the Valley had 

one lead source at the 0.5 tpy threshold. However, this information was based on old 

emissions inventory information, and the District has since determined that the source in 

question closed in 2003. Therefore, neither the original source-oriented monitoring 

requirements nor the proposed changes affect the Valley. 

Toxics

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

– 1st Street, 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, 

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

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

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

quantify several toxic hydrocarbon species. 

Green House Gases

ARB is installing Picarro multi-gas analyzers (CO2, CH4, and water vapor) and a 

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

as part of its Green House Gases (GHG) monitoring program. While the data will not be 

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

Meteorology

Data for a variety of meteorological variables are collected to aid in daily forecasting for 

weather conditions and air quality, exceptional events, long-term planning, and pollutant 

trend assessment. These forecasting 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 16 for the meteorological parameters measured in the Valley. 

Forecasting activities include: 

2010 Air Monitoring Network Plan 

 

31
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

• Reporting and forecasting the AQI for ozone, PM2.5, and PM10 for each of the 

Valley’s eight counties. These forecasts are transferred to EPA’s AIRNOW. 

• Agricultural burn emissions collection for more than 100 burn-zones. 

• Issuance of Public Health Advisories and Health Cautionary Statements when 

required. 

• Prescribed (controlled) burn planning in consultation with the California 

Department of Forestry, National Park Service, National Forest Service and local 

fire districts 

• Residential wood burning declarations from November 1 through February 28 

• Emergency consultations 

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 Street already 

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

ozone, and meteorology. To meet additional NCore requirements, ARB will be installing 

trace level CO, SO2, and NOy monitors at this site in 2010. ARB is also installing a gas 

dilution calibrator, a zero air generator, and digital data loggers to support NCore 

monitoring. NCore sites must also measure PM10-2.5 mass and speciation, but EPA 

has not yet approved monitoring methods for PM10-2.5. 

2010 Air Monitoring Network Plan 

 

32
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

2010 Air Monitoring Network Plan 

 

33

Table 16 Meteorological Monitoring Stations in the San Joaquin Valley 

As of June 1, 2010 

Site Wind 

Speed 

Wind 

Direction 

Outdoor 

Temperature

Relative 

Humidity 

Barometric 

Pressure 

Solar 

Radiation

Arvin X X X X X X 

Bakersfield – California X X X X X X 

Bakersfield – Muni1 X X X X X X 

Clovis – Villa X X X X X X 

Corcoran – Patterson X X X X 

Edison – Johnson X X X 

Fresno – Drummond X X X X 

Fresno – First X X X X X 

Fresno – Sky Park X X X 

Hanford 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 – Stanislaus X X X X 

Merced – Coffee X X X 

Modesto – 14th X X X X 

Oildale – Manor X X X 

Parlier X X X X X X 

Porterville X X X X 

Santa Rosa Rancheria Unknown 

Sequoia National Park 

– Ash Mountain X X X X X 

Sequoia National Park 

– Kaweah X X X X X 

Shafter – Walker Street X X X X X X 

Stockton – Hazelton X X X X 

Tracy – Airport X X X X 

Tranquillity X X X X 

Turlock – Minaret X X X X 

Visalia – Church X X X X 

Visalia - Airport X X X X X X 

1 Bakersfield – Golden was shut down for relocation in December 2009. The replacement site, 

Bakersfield-Muni, will begin reporting data in October 2010. 
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Five-Year Monitoring Network Assessment

40 CFR 58.10(d) requires that the District perform a network assessment every five 

years, with the first assessment due in 2010. This assessment is to take a critical look 

at the air monitoring network and determine whether it is meeting all of EPA’s 

requirements. The District contracted with Sonoma Technology, Incorporated (STI) to 

review the air monitoring network, and STI’s findings were used, in part, to fulfill EPA’s 

requirements for a network assessment as described in the CFR. After considering 

STI’s review (described in more detail below), the District finds that its monitoring 

network meets all EPA’s requirements. 

The assessment evaluated the following: 

• Does the network meet the monitoring objectives defined in appendix D? 

• Are any new sites needed? 

• Whether existing sites are no longer needed and can be terminated? 

• Whether new technologies are appropriate for incorporation into the ambient air 

monitoring network? 

• Does the network support air quality characterization for areas with relatively high 

populations of susceptible individuals? 

• For any site proposed for discontinuance, does it have an effect on data users 

other than the agency? 

• For PM2.5, are there needed changes to population-oriented sites? 

• A copy of the 5-year assessment, along with a revised annual network plan 

needs to be submitted to EPA by July 1, 2010. 

Does the network meet the monitoring objectives defined in appendix D? 

Yes, with the addition of the Porterville and the new site in San Joaquin County 

(Manteca) the District meets the monitoring objectives defined in appendix D. 

Are any new sites needed?

EPA requirements are being met with existing and planned sites. 

Whether existing sites are no longer needed and can be terminated? 

There aren’t any sites that are redundant and should be terminated. However, there is 

no need for the CO monitors at Fresno-Drummond, Fresno-Sierra Sky Park, and the 

Turlock Air Monitoring sites because of the very low levels of CO measured in the 

District. The District is proposing to discontinue measuring CO at these sites. See the 

CO section for more details. 

Whether new technologies are appropriate for incorporation into the ambient air 

monitoring network? 

2010 Air Monitoring Network Plan 

 

34
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

As time progresses, analyzers increase in sophistication and capabilities. When EPA 

changes the requirements or when the District replaces worn out equipment, we replace 

them with analyzers that have the most advanced and reliable technology. For instance 

we are replacing several older PM2.5 monitors with real-time analyzers and we recently 

replaced two CO monitors with trace level CO monitors. 

Does the network support air quality characterization for areas with relatively 

high populations of susceptible individuals? 

Yes, the network supports air quality characterization for areas with relatively high 

populations of susceptible individuals. The majority of the air monitoring sites are 

located in areas of the highest population density. 

For any site proposed for discontinuance, does it have an effect on data users 

other than the agency? 

The five-year network assessment is not proposing to discontinue any sites. However, 

the Bakersfield-Golden State Avenue site is being moved due to the widening of a 

nearby highway, and the Arvin site is being moved due to the termination of the lease 

agreement. 

For PM2.5, are there needed changes to population-oriented sites?

The District will meet the EPA’s requirements for PM2.5 monitoring once the new site in 

San Joaquin County is completed. Currently, the District is planning to put the site in 

Manteca. In addition, the District is planning on installing a PM2.5 monitor at FresnoDrummond to run in parallel with the Fresno-Winery (Pacific College) PM2.5 monitor. If 

the District can determine that the two sites are equivalent, then the District proposes to 

shut down the Fresno-Winery site in order to streamline operations. If the sites are not 

equivalent, the District will remove the PM2.5 monitor at Fresno-Drummond. Before we 

can do this, some infrastructure improvements are necessary at Fresno-Drummond. 

Furthermore, the new monitoring site in Madera will have a PM2.5 BAM FEM, as well as 

a PM10 TEOM. 

A copy of the five-year assessment, along with a revised annual network plan 

needs to be submitted to EPA by July 1, 2010. 

A copy of the assessment performed by Sonoma Technology, Incorporated is attached 

to this report as Appendix C. 

Additional Findings 

STI did a thorough analysis of the air monitoring network, looking at many aspects of 

the network. They made many findings, some of which were used to develop the 

responses above. Two major findings were that there are regional gaps in the air 

monitoring network not covered by monitoring requirements and that there is some 

2010 Air Monitoring Network Plan 

 

35
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

question whether the Parlier Air Monitoring Station is correctly designated as a PAMS 

type 3 site. 

STI determined that there were large areas not represented by air monitoring stations 

and there were other places where meteorological stations (no air monitoring 

equipment, only meteorological measurements) would be useful to have. Specifically 

the District should consider placing air quality monitors in the Los Banos area, northeast 

of Clovis (in the foothills), and between Corcoran and Bakersfield. The idea of 

operating metrological only sites is novel. The places STI suggest, mainly at the foot of 

passes and other important metrological locations, would provide useful information in 

forecasting air pollution levels for today and tomorrow. 

In a District as large as the SJV, locating a monitor at every place of interest is not 

possible. Air monitoring stations are expensive to build, maintain, and operate. It takes 

significant staff time to run a site. Frequently, short-term funding is available for the 

construction of an air monitoring site, yet this still does not cover the long-term cost of 

its year-to-year operation. However, if permanent funding became available, covering 

both short-term and long-term costs, we would consider installing additional sites not 

required by the EPA. 

The Parlier air monitoring site is classified as a PAMS type 3 site. This means that it is 

supposed to measure the downwind peak ozone values. STI found that the peak ozone 

readings in Fresno County move around between Parlier, Fresno-Sierra Sky Park, 

Fresno-First, Fresno-Drummond, and Clovis monitors. This is due in part to the Fresno 

Eddy, a recirculation pattern that brings downwind air back up to the Fresno area. It 

can also mean that the downwind peak has moved further downwind and into the 

foothills. The District needs to take a careful look at this and will do so during our next 

ozone SIP. SIPs require air pollution modeling and the District will investigate where 

the downwind peak is located. 

2010 Air Monitoring Network Plan 

 

36
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Summary of monitoring changes, January 2009 – July 2010

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. This SPM site is used for residential 

wood burning declarations for the Greater Frazier Park Area from November through 

February. This site started reporting to AQS in January 2010. 

The District replaced an older PM2.5 SPM monitor with a newer PM2.5 FEM monitor at 

Bakersfield-Golden State Avenue on June 4, 2009. The District had been operating 

both a filter-based FRM and the new continuous FEM as parallel monitors at 

Bakersfield-Golden (as well as Corcoran and Clovis) to improve understanding of 

differences in measurements, if any. However, the Bakersfield-Golden site was shut 

down in January 2010 for relocation due to adjacent highway construction. The 

expanded highway would invalidate EPA’s siting criteria. 

The District’s Tranquillity monitoring site began operating in the fourth quarter of 2009. 

This SPM site measures PM2.5, meteorology, and ozone; and was established for 

research purposes, and not regulatory purposes. 

The Hanford monitoring site was rebuilt due to safety and structural concerns of the 

previous shelter. The new site began reporting meteorology in February 2010, and the 

ozone monitor that had been temporarily operating in Corcoran was returned to Hanford 

at the same time. The District will also be adding a PM10 TEOM, which will be 

replacing a filter-based PM10 monitor. 

The Porterville site began reporting ozone, PM2.5, and meteorology in March 2010. 

With this site, the Visalia-Porterville CBSA now has two ozone monitors designed to 

report population exposures. It should be noted that the PM2.5 monitor in Porterville is 

non-regulatory. 

As mentioned above, ARB is installing Picarro multi-gas analyzers (CO2, CH4, and 

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

Tranquillity, and Arvin sites as part of its Green House Gases (GHG) monitoring 

program. While the data will not be submitted to AQS at this time, the data will be used 

by ARB’s Research Division. 

 

The District had planned to begin monitoring lead in 2010 to meet federal requirements. 

However, EPA proposed changes to the lead monitoring requirements in December 

2009 (74 FR 69050-69059). The District has thus suspended lead monitoring plans. 

2010 Air Monitoring Network Plan 

 

37
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Summary of changes planned, July 2010 – 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 

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. 

Stockton CBSA/MSA 

Stockton CBSA/MSA needs an additional PM2.5 monitor suitable for comparing to the 

NAAQS. The District has chosen Sierra High School in Manteca for this site. The 

District posted a request for proposal (RFP) to solicit bids for site construction in March 

2010. In response, the Governing Board of the SJVAPCD approved a contract in May 

2010 with a contractor to construct this new site, which should be completed by the 

fourth quarter of 2010. 

The District meets all other EPA monitoring requirements for the other pollutants in this 

CBSA. 

Modesto CBSA/MSA 

The District currently meets all EPA monitoring requirements in this CBSA. 

The District plans to improve its meteorological equipment at the Turlock Air Monitoring 

Site by installing a meteorological tower by the third quarter of 2010. 

Merced CBSA/MSA 

The District currently meets all EPA monitoring requirements in this CBSA. 

Although the District had received notice that the Merced-Coffee Street site had to be 

vacated by December 31, 2011, the District renegotiated the contract so the site can 

now remain through 2015. The District may relocate sooner, but there are no definite 

relocation plans at this time. 

Madera CBSA/MSA 

Madera CBSA/MSA needed an additional PM10 monitor suitable for comparing to the 

NAAQS, so the District built a new site in the County facility located at Avenue 14 and 

Road 28. The site will begin reporting for continuous PM10, ozone, PM2.5, and 

meteorology soon. The District may eventually seek permission from EPA to 

2010 Air Monitoring Network Plan 

 

38
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

consolidate the new Madera site with the Madera-Pump PAMS site, pending the 

comparability of the two sites’ ozone data for the next two years. 

The District meets all other EPA monitoring requirements for the other pollutants in this 

CBSA. 

Fresno CBSA/MSA 

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

Sierra Skypark 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. 

The District meets all other EPA monitoring requirements for the other pollutants in this 

CBSA. 

Hanford-Corcoran CBSA/MSA 

The District currently meets all EPA monitoring requirements in this CBSA. 

Visalia-Porterville CBSA/MSA 

The District and NOAA are upgrading the Visalia-Airport site lower air profiler with 

newer technology. This should be completed in 2010. 

The District meets all other EPA monitoring requirements for the other pollutants in this 

CBSA. 

Bakersfield CBSA/MSA 

The Bakersfield Golden site had to be relocated to due adjacent highway expansion. 

The District will complete the relocation to the Bakersfield Municipal Airport by the end 

of 2010, if not sooner. This new site is about 790 meters (0.5 miles) away from ARB’s 

Bakersfield-Planz site. The District will investigate the possibility of combining these 

sites after the data can be compared, but the combined site would have to meet both 

PAMS and PM2.5 siting criteria. 

After the shutdown of the Bakersfield-Golden site, the District requested ARB’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. 

2010 Air Monitoring Network Plan 

 

39
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

The District is investigating the possibility of relocating the Lebec monitoring site to an 

area with a greater population density. However, there are no final plans for relocation 

at this time. 

The Arvin monitoring site, operated by ARB, needs to be relocated due to an expired 

lease. The site is scheduled to close at the completion of parallel ozone monitoring in 

the fall of 2010. The new site, Arvin-Di Giorgio is intended to become the long-term 

replacement for the Arvin-Bear Mountain Road site. In addition of moving all of the 

existing analyzers to the new site, ARB plans to install methane/CO2 and trace CO 

analyzers for special purpose monitoring. 

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

the latest regulation for PAMS Type 3 sites. 

The District meets all other EPA monitoring requirements for the other pollutants in this 

CBSA. 

Other PM changes 

The District is upgrading many of its filter-based FRM PM2.5 monitors to near 

continuous FEM (BAM-1020s) monitors, where possible, to allow for both daily AQI 

reporting and comparisons to the NAAQS. Currently, the District is conducting parallel 

PM2.5 monitoring at Corcoran to evaluate the comparability of PM2.5 data from the two 

types of monitors for the SJV. 

The District is also upgrading the PM10 monitoring network from filter-based monitors to 

real-time monitors. The upgrade brings improved temporal resolution to the District’s 

rigorous PM10 monitoring program. The upgrade will also result in a cost savings 

through less staff travel time, less maintenance, and fewer filters to weigh. 

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 ARB based on their 

scheduled audits. 

The District submitted its 2009 data certification to the EPA. Annual certifications are 

due by May 1 of each year. 

2010 Air Monitoring Network Plan 

 

40
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Acronyms, Abbreviations, and Initialisms

AIRS: Aerometric Information Retrieval System; replaced with AQS 

AQI: Air Quality Index 

AQS: Air Quality System 

ARB: 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 

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

2010 Air Monitoring Network Plan 

 

41
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

This page intentionally blank.

2010 Air Monitoring Network Plan 

 

42
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Appendix A: Monitoring Site Descriptions

Sites operated by the SJVAPCD

Bakersfield – Golden State Avenue; Bakersfield - Muni 

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

replacement site, Bakersfield-Muni, will begin reporting data in October 2010. 

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-Muni 

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

metropolitan area. Bakersfield-Muni is to begin operating in October 2010 to replace 

the Bakersfield-Golden site, which operated from June 1994 to December 2009. This 

site was established as a PAMS Type 2 site, sited to measure maximum ozone 

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

PM2.5, PM10, CO, NO2, NMOC, NMHC, and meteorology. The Muni site will monitor 

PM10 (FRM and TEOM, both SLAMS), PM2.5 (BAM, SPM) 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. 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 – N Villa Avenue 

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 Avenue 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 

Appendix A: Air Monitoring Site Descriptions 

Draft Air Monitoring Network Plan 

 

A-1
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

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. 

Corcoran – Patterson Avenue 

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) 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 St 

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 Street 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 

Appendix A: Air Monitoring Site Descriptions 

Draft Air Monitoring Network Plan 

 

A-2
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

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 – 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 – S Irwin St 

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-S Irwin Street 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 S Irwin Street 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 and ozone monitors were 

temporarily moved to Corcoran during site reconstruction. In February 2010, the 

Hanford-S Irwin Street site became operational once again, and the ozone (SLAMS) 

and PM2.5 (BAM, SLAMS) monitors returned to Hanford. 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. 

Appendix A: Air Monitoring Site Descriptions 

Draft Air Monitoring Network Plan 

 

A-3
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

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. This site currently 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. It will become operational in June 2010, and it is planned to measure ozone 

(SLAMS), PM2.5 (BAM FEM, SLAMS), PM10 (TEOM, SLAMS), and meteorology. This 

is a new monitoring site for the SJVAPCD, and so its air quality trends and 

characteristics are yet to be known. However, it is intended 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. 

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 

Appendix A: Air Monitoring Site Descriptions 

Draft Air Monitoring Network Plan 

 

A-4
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

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 Rd 

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 Street 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 St 

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-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, 

Appendix A: Air Monitoring Site Descriptions 

Draft Air Monitoring Network Plan 

 

A-5
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

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. This is a new monitoring site for 

the SJVAPCD, and so its air quality trends and characteristics are yet to be known. It is 

approximately 25 miles southeast of Visalia, CA, and so transport of pollutants from 

Visalia towards Porterville is possible. This site will measure ozone (SLAMS), PM2.5 

(BAM, SPM), and meteorology. This site will represent air quality levels present near the 

foothills of the southern Valley and will give the district an indication of exposure of 

pollutants to the local population.

Stockton – Wagner - Holt School 

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 School 

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. 

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. 

Appendix A: Air Monitoring Site Descriptions 

Draft Air Monitoring Network Plan 

 

A-6
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

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 – S Minaret St 

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-Minaret Street 

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 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. 

Appendix A: Air Monitoring Site Descriptions 

Draft Air Monitoring Network Plan 

 

A-7
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Sites Operated by the ARB

Arvin 

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 monitoring site 

is operated by the CARB and is located 24 miles southeast of the Bakersfield, CA 

metropolitan area. It began operating in June 1989. 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. 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 – Plantz/Airport 

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-Airport 

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 

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 

Appendix A: Air Monitoring Site Descriptions 

Draft Air Monitoring Network Plan 

 

A-8
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

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 St 

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 

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 St 

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 

Appendix A: Air Monitoring Site Descriptions 

Draft Air Monitoring Network Plan 

 

A-9
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

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 

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 

Appendix A: Air Monitoring Site Descriptions 

Draft Air Monitoring Network Plan 

 

A-10
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

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. 

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 monitoring 

site is operated by SJVAPCD. 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. 

Appendix A: Air Monitoring Site Descriptions 

Draft Air Monitoring Network Plan 

 

A-11
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

Special Purpose Monitoring Sites

Sequoia National Park – 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 National Park – 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 

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. 

Sequoia National Forest – Springville and Pinehurst

The Springville and Pinehurst monitoring stations are permanent sites operated by 

Sequoia National Forest. They are located at the southern end of the Sierra Nevada at 

1,432-foot and 4,985 foot elevations respectively. Sequoia National Forest also 

operates nine additional portable monitors that are moved to different locations as 

needed. The Springville and Pinehurst sites demonstrate hourly ozone and PM2.5 

responses in rural areas. The SJVAPCD uses these sites for informational purposes 

when smoke impacts are occurring in communities due to wildfires or prescribed 

burning projects.

Appendix A: Air Monitoring Site Descriptions 

Draft Air Monitoring Network Plan 

 

A-12
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

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. 

Appendix A: Air Monitoring Site Descriptions 

Draft Air Monitoring Network Plan 

 

A-13
San Joaquin Valley Unified Air Pollution Control District June 30, 2010

This page intentionally blank. 

Appendix A: Air Monitoring Site Descriptions 

Draft Air Monitoring Network Plan 

 

A-14