Ambient 

Air 

Monitoring 

Network 

Plan

2013

Ventura County Air Pollution Control District

Monitoring Division

KENT FIELD, MANAGER

669 COUNTY SQUARE DRIVE • VENTURA, CA 93003 • 805-645-1400

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Table of Contents

1 Introduction.....................................................................................................................1

2 Overview of Network Operation ....................................................................................2

2.1 Ambient Air Monitoring Network in Ventura County.....................................................2

2.2 Monitoring Objectives and Spatial Scales.....................................................................6

2.3 Local Monitoring Objectives and Local Spatial Scales.................................................8

2.3.1 Ozone Monitoring Network............................................................................................9

2.3.2 PM2.5 and PM10 Monitoring Network .............................................................................9

2.3.3 Speciation Trends Network (STN), Chemical Speciation Network (CSN)................ 10

2.3.4 Photochemical Assessment Monitoring Stations (PAMS) ........................................ 11

2.3.5 California Air Resources Board Toxic Air Contaminant Sampling............................ 11

2.4 Air Quality Data........................................................................................................... 11

3 Recent and Pending Modifications to the Air Monitoring Network............................ 13

3.1 Network Operations - July 2012 to June 2013 .......................................................... 13

3.1.1 Network Operations with No Recent Changes.......................................................... 13

3.1.2 Recent Changes to the PM2.5 and PM10 Monitoring Networks ................................. 13

3.1.3 Recent Changes to the Data Acquisition and Management System........................ 14

3.1.4 Recent Changes to Laboratory Filter Processing Operations................................... 15

3.1.5 Replacement of Analyzers and Equipment Since Last Reporting Period ................ 15

3.2 Network Operations – Post June 2013 ...................................................................... 17

3.2.1 Network Operations with No Proposed Changes...................................................... 17

3.2.2 Future Changes to the PM2.5 and PM10 Monitoring Network .................................... 17

3.2.3 Future Changes to the Speciation Trends Network .................................................. 17

3.2.4 Future Changes - New NO2 Near-Road Monitoring Station ..................................... 18

3.2.5 Future Changes to the PAMS Network...................................................................... 19

3.2.6 Future Changes to the Data Acquisition and Management System......................... 20

3.2.7 Future Replacement of Analyzers and Equipment.................................................... 21

Appendix A 2013 Annual Air Monitoring Network Plan Checklist ....................................A-1

Appendix B Detailed Site Information................................................................................B-1

Appendix C Minimum Monitoring Requirements...............................................................C-1

Appendix D Ambient Air Quality Standards as of 2012 ....................................................D-1

Appendix E Collocation Requirements..............................................................................E-1

Appendix F Air Monitoring Network Related Correspondence ..................................F-1

List of Figures

Figure 1 – VCAPCD Monitoring Regions and Ambient Monitoring Stations.................... 4
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List of Tables

Table 1 – Air Monitoring Stations and Pollutants Monitored in 2013 ............................... 3

Table 2 – Site Types and Appropriate Spatial Scales ..................................................... 7

Table 3 – Pollutants, Monitoring Objectives and Spatial Scales...................................... 7

Table 4 – Local Air Monitoring Regions - Area and Population Served........................... 9

Table 5 – Sources of Ambient Air Quality Data ............................................................. 12

Table 6 – Analyzer and Equipment Replacement – July 2012 to June 2013 ................ 16

Table 7 – Analyzer and Equipment Replacement – Post June 2013 ............................ 21

Table 8 – Location of Submitted Information – 2013 Ambient Air Monitoring 

Network Plan...............................................................................................A-2

Table 9 – El Rio Station Information.............................................................................B-1

Table 10 – Ojai Station Information..............................................................................B-5

Table 11 – Piru Station Information..............................................................................B-7

Table 12 – Simi Valley Station Information...................................................................B-9

Table 13 – Thousand Oaks Station Information .........................................................B-15

Table 14 – Simi Valley – Upper Air Station Information..............................................B-17

Table 15 – Meteorological Data Collected at Sites.....................................................B-17

Table 16 – Minimum Monitoring Requirements for Ozone .......................................... C-1

Table 17 – Minimum Monitoring Requirements for PM2.5 SLAMS ............................... C-2

Table 18 – Minimum Monitoring Requirements for Continuous PM2.5 Monitors .......... C-2

Table 19 – Minimum Monitoring Requirements for PM10............................................. C-3

Table 20 – Minimum Monitoring Requirements for PM10-2.5......................................... C-3

Table 21 – Minimum Monitoring Requirements for NO2 .............................................. C-4

Table 22 – Minimum Monitoring Requirements for SO2 .............................................. C-5

Table 23 – Minimum Monitoring Requirements for CO ............................................... C-5

Table 24 – Minimum Monitoring Requirements for Pb at NCore ................................. C-6

Table 25 – Source Oriented Lead Monitoring (Including Airports)............................... C-6

Table 26 – Ambient Air Quality Standards .................................................................. D-1

Table 27 – VCAPCD Air Monitoring Network Correspondence....................................F-1
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Glossary of Acronyms

AQI Air Quality Index

AQS Air Quality System

ARM Approved Regional Method

BAM Beta Attenuation Monitor

CARB California Air Resources Board

CAAA Clean Air Act Amendments

CBSA Core Based Statistical Area

CFR Code of Federal Regulations

CO Carbon Monoxide

CSN Chemical Speciation Network

EDAS Ethernet Data Acquisition System

EPA United States Environmental Protection Agency

FEM Federal Equivalent Method

FRM Federal Reference Method

Hwy Highway

NAAQS National Ambient Air Quality Standards

NAMS National Air Monitoring Stations

NCore National Core Air Monitoring Sites

MSA Metropolitan Statistical Area

NEI National Emissions Inventory

NO Nitric Oxide

NO2 Nitrogen Dioxide

NOx Nitrogen Oxides

NOy Reactive Nitrogen Compounds

O3 Ozone

PAMS Photochemical Assessment Monitoring Stations

Pb Lead

PM Particulate Matter

PM2.5 Particulates less than or equal to 2.5 microns in size

PM10 Particulates less than or equal to 10 microns in size

POC Parameter Occurrence Code

PQAO Primary Quality Assurance Organization

PSD Prevention of Significant Deterioration

PWEI Population-Weighted Emission Index

SASS Speciation Air Sampling System

SIP State Implementation Plan

SJVAPCD San Joaquin Valley Air Pollution Control District

SLAMS State and Local Air Monitoring Stations
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Glossary of Acronyms (cont’d)

SO2 Sulfur Dioxide

SR State Route

STN Speciation Trends Network

TAD Technical Assistance Document

TNMOC Total Non-Methane Organic Compounds

VCAPCD Ventura County Air Pollution Control District

VOC Volatile Organic Compounds
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1 Introduction

The Ventura County Air Pollution Control District’s (VCAPCD) 2013 Ambient Air Monitoring 

Network Plan is an examination and evaluation of the VCAPCD’s network of ambient air 

pollution monitoring stations. This annual review of the VCAPCD’s State and Local Air 

Monitoring Stations (SLAMS) air monitoring network is required by Title 40, Code of Federal 

Regulations, Part 58.10 (40 CFR 58.10). The report meets the requirements for an annual 

network plan as listed in 40 CFR 58.10, Appendix A.

As required by the regulations, this report includes monitors which are federal reference 

methods (FRM) or federal equivalent methods (FEM). While the CFR also requires reporting 

of approved regional methods (ARM), no ARMs are in operation within VCAPCD at this 

time. The terms FRM, FEM, and ARM denote monitoring instruments that produce 

measurements of the ambient pollution levels that the regulations allow to be compared to 

the National Ambient Air Quality Standards (NAAQS) for regulatory purposes.

Federal regulations require specific detailed monitoring network information be included in 

the annual network plans. A summary of the requirements, and how the VCAPCD has met 

each of the requirements, can be found in Appendix A. The 2013 Ambient Air Quality 

Monitoring Network Plan includes a review of actions taken since preparation of the last plan 

(July 2012), and plans for action in the year ahead.

This report will be available for a 30 day public inspection period. Any comments received 

during the public inspection period will be forwarded to the United States Environmental 

Protection Agency (EPA) concurrently with submittal of the plan. This report may be viewed 

on the VCAPCD’s website, www.vcapcd.org and hardcopies are available for review at

VCAPCD’s office. Written comments should be submitted to Kent Field, Monitoring Division 

Manager, at kent@vcapcd.org, 805-662-6960.
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2 Overview of Network Operation

The VCAPCD operates five air monitoring stations and one atmospheric profiler within 

Ventura County. The VCAPCD’s SLAMS monitoring network has been designed to provide 

ozone (O3), fine particulate matter of a size of 2.5 microns or less (PM2.5) and particulate 

matter of a size of 10 microns or less (PM10) monitoring coverage to the majority of the 

inhabited regions of Ventura County. The VCAPCD has conducted air monitoring for ozone 

or oxidants in the county since 1963. This monitoring network plays a critical role in 

assessing clean air progress and in determining pollutant exposures throughout Ventura 

County.

2.1 Ambient Air Monitoring Network in Ventura County

Ventura County is located along the southern portion of the central California coast between 

Santa Barbara and Los Angeles Counties. Its diverse topography is characterized by 

mountain ranges to the north, two major river valleys (the Santa Clara, which trends eastwest, and the Ventura, which trends roughly north-south), and the Oxnard Plain to the south 

and west. As pollutants are carried into the inland valleys by prevailing winds, they are 

frequently trapped against the mountain slopes by a temperature inversion layer, generally 

occurring between 1500 and 2500 feet above sea level. Above the temperature inversion 

layer, pollutants are allowed to disperse freely. Our air monitoring stations are therefore 

found between the coast and the inland valley mountain foothills up to approximately 1000 

feet.

The purposes of the VCAPCD’s air monitoring network are: 1) to determine Ventura 

County’s attainment status for the National and California standards for ozone, PM2.5 and 

PM10; 2) to track Ventura County’s air quality trends; 3) to provide information to the public 

about the quality of Ventura County’s air (i.e., reporting of the Air Quality Index (AQI) and 

ozone and particulate episode forecasting); and, 4) for data in air quality modeling efforts.

Ambient concentration data are collected for a wide variety of pollutants. The most 

important of these in Ventura County are ozone, PM2.5, and PM10. Other pollutants 

measured include oxides of nitrogen (NOx), nitric oxide (NO), nitrogen dioxide (NO2), total 

non-methane organic compounds (TNMOC), speciated PM2.5, toxics (hexavalent chromium, 

total metals and aldehydes), volatile organic compounds (VOC), and carbonyls. 

Measurement of meteorological parameters is also conducted at all monitoring stations.

Data for all of the pollutants is used to better understand the nature of the ambient air quality 

in Ventura County, as well as to inform the public about the quality of the air. 
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Not all pollutants are monitored at all stations. Most stations monitor for multiple pollutants, 

while some stations monitor only two pollutants. A particular station’s location and 

monitoring purpose determine the actual pollutants measured at that station.

The majority of the population1resides in the southern half of Ventura County - the 

VCAPCD has focused its air monitoring efforts there. The south half of Ventura County is 

divided into five air monitoring regions: Ventura and the Oxnard Coastal Plain, Ojai Valley, 

Santa Clara River Valley, Simi Valley, and the Conejo Valley. The air monitoring network 

has been designed to provide air monitoring coverage to those regions of Ventura County.

Table 1 lists the pollutants measured in 2013 at each monitoring station, and the assigned 

Air Quality System identification (AQS ID) number for each monitoring station. 

Table 1 – Air Monitoring Stations and Pollutants Monitored in 2013

Station Name

AQS ID

OzoneNO2 (area-wide)PM2.5 FRMPM2.5

F

E

M

PM2.5 non-FEMPM2.5 SpeciationPM10 FRMPM10 FEMMeteorology

Other

Parameters

El Rio – Rio Mesa School #2

061113001       

VOC

Carbonyls

Toxics***

Ojai – Ojai Avenue

061111004   

Piru – Pacific Avenue

061110009   

Simi Valley – Cochran Street

061112002     * **  

VOC

TNMOC

Toxics***

Simi Valley Upper Air

061110008  Profiler

Thousand Oaks – Moorpark Rd

061110007    

* SASS and URG samplers, monitored as part of 

Speciation Trends Network (STN), Chemical 

Speciation Network (CSN).

** Main and Collocated Samplers

*** California Air Resources Board

 Monitored as part of SLAMS network.

 Monitored as part of Photochemical Assessment 

Monitoring Stations (PAMS) network.

 Monitored as part of SLAMS and PAMS networks.

Figure 1 shows Ventura County’s air monitoring regions and the locations of the monitoring 

stations. 

 

1 All population estimates in this document are based on the 2010 US census.
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Figure 1 – VCAPCD Monitoring Regions and Ambient Monitoring Stations
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A description of each of the five monitoring regions is presented below.

Ventura and the Oxnard Coastal Plain – a broad coastal area stretching from the Pacific 

Ocean to several inland valleys, covering 405 square miles, and having a population of

433,245 people. This area encompasses the cities of Port Hueneme, Ventura, Oxnard and 

Camarillo. The Oxnard plain area is a relatively flat plain area with foothills and mountains at 

its northern border. This area is home to considerable agricultural activities and includes a 

deepwater port and a number of Ventura County’s major stationary sources2, including two 

natural gas-fired electric generating units, two naval bases, several natural gas-fired 

cogeneration facilities, several oil and gas production and processing facilities, and a paper 

products manufacturer. The area is impacted by mobile sources and marine shipping 

operations occurring off Ventura County’s coast. This area is served by the VCAPCD’s 

monitoring station at Rio Mesa High School, Central Avenue, in Oxnard.

Ojai Valley – an inland area including the City of Ojai and the communities of Oak View, and 

Meiners Oaks, covering 102 square miles, and having a population of 27,784 people. The 

Ojai Valley is surrounded by mountain ranges. There is one major stationary source on the 

southeastern edge of the region; however, the Ojai Valley may be influenced by oil 

production activities occurring to the south, in the Ventura Coastal area. The area is 

impacted primarily by mobile sources. The Ojai Valley is served by the VCAPCD’s 

monitoring station at Ventura County fire station, Ojai Avenue, in Ojai.

Santa Clara River Valley – an inland area, covering 204 square miles, and having a 

population of 45,107 people. The Valley is surrounded by foothills and low-lying mountains. 

The eastern edge of the Santa Clara River Valley is the border between Ventura and Los 

Angeles Counties. The area is also home to considerable agricultural activities. There are 

oil production and processing activities occurring throughout the Santa Clara River Valley. 

There are two major stationary sources in its boundaries. The area is impacted primarily by 

mobile sources. This area is served by the VCAPCD’s monitoring station on Pacific 

Avenue, in Piru.

Simi Valley – an inland area, including the cities of Simi Valley and Moorpark, covering 142 

square miles, and having a population of 162,683 people. Simi Valley is surrounded by 

foothills and low-lying mountains. The eastern edge of the Simi Valley is the border between 

Ventura and Los Angeles Counties. There are two major stationary sources in its 

boundaries. The area is impacted primarily by mobile sources. This area is served by the 

VCAPCD’s monitoring station at Simi Valley High School, on Cochran Street, in Simi Valley.

 

2

For the purpose of this report a major stationary source is considered to be a facility that has been issued a federal Part 70 operating permit 

(also referred to as a Title V permit).
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Conejo Valley – an inland area, including the city of Thousand Oaks and the communities of 

Westlake Village and Newbury Park, covering 75 square miles, and having a population of

153,680 people. The area is surrounded by foothills and low-lying mountains. The eastern 

edge of the Conejo Valley is the border between Ventura and Los Angeles Counties. There 

are no major stationary sources in its boundaries. The area is impacted primarily by mobile 

sources. This area is served by the VCAPCD’s monitoring station at Thousand Oaks High 

School, Moorpark Road, in Thousand Oaks.

2.2 Monitoring Objectives and Spatial Scales

Federal regulations (40 CFR 58, Appendix D), require that a SLAMS network be designed to 

meet three monitoring objectives: 

1. To provide air pollution data to the public in a timely manner;

2. To support compliance with the NAAQS; and,

3. To support air quality research.

In support of the monitoring objectives above, the monitoring network must be designed with 

a variety of site types. Sites can be designed:

1. To determine the highest concentration expected to occur in the area covered by the 

network;

2. To determine typical concentrations in areas of high population density;

3. To determine the impact on ambient pollution levels of significant sources or source

categories;

4. To determine general background concentration levels;

5. To determine the extent of regional pollutant transport among populated areas, and 

in support of secondary standards; and,

6. To determine the welfare-related impacts in more rural and remote areas (such as 

visibility impairment and effects on vegetation).

The physical siting of an air monitoring station must achieve a spatial scale of 

representativeness that is consistent with the site type of the monitor. The spatial scale 

results from the physical location of the station with respect to the pollutant sources. It 

estimates the size of the area surrounding the monitoring station that experiences uniform 

pollutant concentrations.

The categories of spatial scale are:

1. Microscale – An area of uniform pollutant concentrations ranging from several meters 

up to 100 meters.
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2. Middle Scale – Uniform pollutant concentrations in an area of about 100 meters to 

0.5 kilometer.

3. Neighborhood Scale – An area with dimensions in the 0.5 to 4.0 kilometer range.

4. Urban Scale - Citywide pollutant conditions with dimensions ranging from 4 to 50 

kilometers.

5. Regional Scale – A large area, usually rural, of the same general geography and 

without large sources that extends from tens to hundreds of kilometers.

Table 2 shows the relationship between site types and the spatial scales that are generally 

appropriate to those site types.

Table 2 – Site Types and Appropriate Spatial Scales

Site Type Appropriate Spatial Scale 

Highest Concentration Micro, Middle, Neighborhood

Population Oriented Neighborhood, Urban

Source Impact Micro, Middle, Neighborhood

General/Background & regional transport Urban, Regional

Welfare-related Urban, Regional

Table 3 shows each of the VCAPCD’s air monitoring stations and its criteria pollutant 

objective and spatial scales. Appendix B presents detailed site information about each of 

the monitoring stations in Ventura County

Table 3 – Pollutants, Monitoring Objectives and Spatial Scales

Pollutant Monitoring Station

Monitoring Objectives and Spatial Scale

NAAQS

Comparison

Public 

Information Research Spatial Scale

Ozone

El Rio  Urban

Ojai  Urban

Piru  Urban

Simi Valley  Urban

Thousand Oaks  Urban

NO2

El Rio  Urban

Simi Valley  Urban
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Table 3 – Pollutants, Monitoring Objectives and Spatial Scales (cont’d)

Pollutant Monitoring Station

Monitoring Objectives and Spatial Scale

NAAQS

Comparison

Public 

Information Research Spatial Scale

PM2.5

El Rio  Neighborhood

Ojai  Neighborhood

Piru  Neighborhood

Simi Valley   Neighborhood

Thousand Oaks  Neighborhood

PM10

El Rio  Neighborhood

Simi Valley  Neighborhood

VOCs

El Rio  Neighborhood

Simi Valley  Urban

TNMOC Simi Valley  Urban

Carbonyls El Rio  Urban

PM2.5Speciation Simi Valley  NA*

Toxics

El Rio  NA

Simi Valley  NA

* Not Applicable 

2.3 Local Monitoring Objectives and Local Spatial Scales 

Each of the VCAPCD’s air monitoring stations has, at a minimum, an ozone monitor. 

Monitors at some stations include PM2.5 FRM monitors, continuous PM2.5 FEM or non-FEM 

monitors, PM10 FRM monitors, continuous PM10 FEM monitors, continuous TNMOC, and 

oxides of nitrogen (NO, NOX, NO2). The VCAPCD has located each of its air monitoring 

stations in relation to specific geographic areas of Ventura County (Section 2.1), depending 

upon each area’s population, topography and meteorology. The north half of Ventura 

County is mountainous and sparsely populated, covering nearly 900 square miles, and 

having a population of only 819 people (population density of less than 1 person/square 

mile), so no air monitoring stations are located in that area. Because the VCAPCD has 

designed its network with consideration given to the distinct geographic, topographic and 

meteorological areas of Ventura County, the areas and population served by VCAPCD’s air 

monitoring stations vary greatly. The local monitoring objective for VCAPCD’s monitoring 

stations is reporting the Air Quality Index (AQI) and for ozone episode forecasting. The local 

spatial scale for VCAPCD’s monitoring stations is urban or neighborhood as previously 

described. 
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Table 4 contains the local regions in Ventura County and the population served by each of 

its air monitoring stations.

Table 4 – Local Air Monitoring Regions - Area and Population Served

Station Name and 

Region Served AQS ID

Area Served 

(Sq. Mi.)

Population 

Served

Population 

Density 

(Pop./Sq. Mi)

El Rio – Rio Mesa School #2 

Region: Ventura and the 

Oxnard Coastal Plain

061113001 405 433,245 1070

Ojai – Ojai Avenue 

Region: Ojai Valley 061111004 102 27,784 272

Piru – Pacific Avenue 

Region: Santa Clara River 

Valley

061110009 204 45,107 221

Simi Valley – Cochran Street

Region: Simi Valley 061112002 142 162,683 1146

Thousand Oaks – Moorpark 

Road 

Region: Conejo Valley

061110007 75 153,680 2049

Appendix C of this document describes the minimum monitoring requirements for air 

monitoring networks in Ventura County. These requirements are specified in 40 CFR 58.10, 

Appendix D. Appendix C also presents documentation for pollutants for which no monitoring 

is required in Ventura County.

2.3.1 Ozone Monitoring Network

Ventura County is a serious nonattainment area for the federal 8-hour ozone standard. The 

VCAPCD monitors for ozone hourly at all of its air monitoring stations (El Rio, Ojai, Piru, 

Simi Valley, and Thousand Oaks), except the Simi Valley Upper Air station. The NAAQS for 

ozone is based on the 4th highest annual 8-hour maximum average in parts per million 

(ppm) (level: .075). Appendix D presents the NAAQS as of 2012. The level of the NAAQS 

has been exceeded at various monitoring stations in Ventura County. The ozone NAAQS is 

exceeded most frequently at Simi Valley, followed by Ojai and Piru. The El Rio monitoring 

station infrequently exceeds the ozone NAAQS. The maximum ozone concentration for 

2012 was at .087 ppm, recorded at the Simi Valley monitoring station.

2.3.2 PM2.5 and PM10 Monitoring Network

The VCAPCD’s particulate monitoring network consists of monitors for PM2.5 and PM10. 

Ventura County is in attainment of the federal PM2.5 and PM10 NAAQS. The PM2.5 network 
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has been operating since 1999, in response to establishment of the federal PM2.5 standard 

in 1999. VCAPCD has had PM10 monitors operating since late 1986 in Ventura County.

The PM2.5 monitoring network includes three PM2.5 FRM monitors (El Rio, Simi Valley, and 

Thousand Oaks). It also includes four continuous PM2.5 FEM monitors (El Rio, Ojai, Piru, 

and Thousand Oaks); and one continuous PM2.5 non-FEM monitor (Simi Valley), that all 

monitor PM2.5 hourly. The annual PM2.5 NAAQS is based on the annual weighted mean of 

the 24-hour averages, in μg/m3(level: 15). The 24-hour NAAQS for PM2.5 is based on the 

98th percentile 24-hour average, in μg/m3(level: 35).

The PM10 monitoring network includes three PM10 FRM monitors (El Rio, and Simi Valley 

(primary and collocated)), and two PM10 FEM monitors (El Rio and Simi Valley). The 24-

hour NAAQS for PM10 is set at a level not to be exceeded more than once per year, on 

average, over 3 years, in μg/m3(level: 150).

Appendix E presents documentation of monitor collocation requirements as specified in 40 

CFR 58 Appendix A, Section 3. Appendix E also presents documentation for pollutants for 

which there are no collocation requirements in Ventura County.

There are no PM2.5 or PM10 monitors required for SIP or maintenance planning.

2.3.3 Speciation Trends Network (STN), Chemical Speciation Network (CSN)

Under the STN, a part of the CSN, VCAPCD operates a speciation monitor at the Simi 

Valley air monitoring station. Samples collected from the speciation samplers are analyzed 

by an EPA contractor. The samplers, a Speciation Air Sampling System (SASS) and URG 

carbon sampler, are maintained by VCAPCD for EPA. The Met One SASS sampler has 

been operational since 12/01/2001, and the URG 3000 N sampler since 03/01/2009.

VCAPCD has responsibility to receive the SASS and URG filters, maintain and operate the 

samplers, and return the exposed filters to the EPA contractor for analysis. The SASS filter 

module and URG filter cassette are sent to VCAPCD to be run and then returned on a tight 

(1-in-3 day, alternate) schedule to an EPA contractor for analysis. Although we are fulfilling 

our responsibilities described above, VCAPCD has had difficulty meeting the receiving, run, 

and pickup schedules set by the EPA in the alternate 1-in-3 day sampling schedule. Our 

discussion of these issues with EPA Region 9 reveals this to be a common problem. EPA

Region 9, the EPA’s contractor, and VCAPCD will be refining these sampling procedures 

and schedules. 

Other aspects of the CSN, such as independent field auditing, are the responsibility of 

agencies other than the VCAPCD. The California Air Resources Board (CARB) and EPA 
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are currently exploring assignment of the role of Primary Quality Assurance Organization 

(PQAO) for the CSN monitoring program. To our knowledge, this issue has not been 

resolved. Currently, no outside auditing is being conducted for this program, and no audits 

have been completed since at least 2008.

2.3.4 Photochemical Assessment Monitoring Stations (PAMS)

Section 182(c)(1) of the 1990 Clean Air Act Amendments (CAAA) required the EPA 

Administrator to promulgate rules for the enhanced monitoring of ozone, NOx, and VOC to 

obtain more comprehensive and representative data on ozone air pollution. Immediately 

following the promulgation of such rules, the affected States were to commence such 

actions as were necessary to adopt and implement a program to improve ambient 

monitoring activities and the monitoring of emissions of NOx and VOC. 

Each State Implementation Plan (SIP) for the affected areas must contain measures to 

implement the ambient monitoring of such air pollutants. The 40 CFR 58 required States to 

establish PAMS as part of their SIP monitoring networks in ozone nonattainment areas 

classified as serious, severe, or extreme. The principal reasons for requiring the collection 

of additional ambient air pollutant and meteorological data are the number of ozone 

nonattainment areas nationwide, and the need for a more comprehensive air quality 

database for ozone and its precursors. The chief objective of the enhanced ozone 

monitoring revisions is to provide an air quality database that will assist air pollution control 

agencies in evaluating, tracking the progress of, and, if necessary, refining control strategies 

for attaining the ozone NAAQS.

2.3.5 California Air Resources Board Toxic Air Contaminant Sampling

VCAPCD collects toxic samples (metals, hexavalent chromium, and aldehydes) at our Simi 

Valley air monitoring site. Our Simi Valley air monitoring site, one of 20 statewide sites, is 

part of the CARB Toxics Monitoring Network within major urban areas to provide data to 

determine the average annual concentrations of toxic air contaminants as input to the 

identification process, and to assess the effectiveness of controls.

Additionally, VCAPCD is part of the CARB toxics monitoring program for pesticides. CARB 

monitors pesticides at our El Rio air monitoring site.

2.4 Air Quality Data

VCAPCD’s air monitoring stations report data to the EPA’s Air Quality System (AQS)

database. The data generated at these stations are public information and are available in 

various formats from the respective agencies. Table 5 lists some sources for air quality data.
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Table 5 – Sources of Ambient Air Quality Data

Agency Address For Data Requests Internet Address Data Available

Ventura County 

APCD

669 County Square Drive

Ventura, CA 93003 http://www.vcapcd.org/ Ventura County

California Air 

Resources Board

PO Box 2815

Sacramento, CA 95812

http://www.arb.ca.gov/html/ds.

htm

California Air 

Monitoring Data

United States 

Environmental 

Protection Agency

Ariel Rios Building

1200 Pennsylvia Avenue, N.W.

Washington, DC 20460

http://www.epa.gov/airdata/ National Air 

Monitoring Data

Real time air quality and meteorological data is available on CARB’s Air Quality and 

Meteorological Information System at http://www.arb.ca.gov/aqmis2/aqmis2.php .

Federal regulations require that air monitoring organizations submit precision and accuracy 

data for the data reported to AQS. VCAPCD air monitoring precision data are submitted to 

the EPA AQS database on a quarterly basis and are up to date as of the publication of this 

report. Accuracy data are reported to the EPA by CARB.

Federal regulations require the air monitoring organizations to annually submit a letter 

certifying that ambient data and quality assurance data are completely submitted to AQS 

and that the ambient data are accurate to the best of our knowledge taking into 

consideration the quality assurance findings. VCAPCD’s 2012 annual data certification was 

submitted to EPA on 05/01/2013. A copy of this letter is provided in Appendix F.
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13 VENTURA COUNTY APCD MONITORING DIVISION

3 Recent and Pending Modifications to the Air Monitoring Network

40 CFR 58.14(b) requires that the EPA review and approve modifications to a SLAMS 

monitoring network, and requires the responsible state or local agency to inform the EPA of 

any proposed modifications. This provides an opportunity for review and comment on the 

possible regulatory consequences of such action. Furthermore, the VCAPCD generally

would conduct a period of parallel sampling of monitors or if a station is moved, at the 

current station and the proposed station for a term of several months to one year, depending 

upon the pollutant, the NAAQS that is of most concern, and on other factors. 

3.1 Network Operations - July 2012 to June 2013

This section describes the changes made to VCAPCD’s monitoring network since the 

publication of the 2012 Ambient Air Monitoring Network Plan, and through June 2013.

3.1.1 Network Operations with No Recent Changes

No changes were made to the ozone, particulate, speciation trends, or PAMS monitoring 

networks during this network plan reporting period. 

3.1.2 Recent Changes to the PM2.5 and PM10 Monitoring Networks

On November 22, 2011, VCAPCD wrote a request to EPA (“Request for Approval of 

Modifications to Particulate Monitoring Networks”, see Appendix F). The primary focus of 

the request was to transition from collecting particulate data via filter media to a continuous 

particulate sampling at all of our air monitoring sites. 

FRM filter sampling is an aged method of estimating the concentration of sized particulates 

in the air. The FRM particulate filter sampling method is a 24 hour sample that requires an 

additional 7 to 14 days for processing and computation of the particulate data for that 24 

hour sample. Additionally, FRM data is collected on a 1-in-3 or 1-in-6 day interval. So, FRM 

particulate data is not available for every day. 

On October 17, 2006, EPA published revisions to ambient air monitoring regulations that 

included new performance criteria for acceptance of continuous PM2.5 monitors as Class III

FEMs. PM2.5 Class III FEMs are analyzers capable of providing ambient air measurements 

representative of one-hour or shorter period integrated PM2.5 concentrations as well as 24-

hour measurements determined as, or equivalent to, the mean of 24 consecutive one-hour 

measurements. These FEM particulate samplers run continuously and report their data 

hourly. The FEM continuous particulate samplers provide real-time (hourly) data for an 
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14 VENTURA COUNTY APCD MONITORING DIVISION

immediate response to air quality issues. 

FEM data readily fulfills the VCAPCD mission statement “To protect public health and 

agriculture from the adverse effects of air pollution by identifying air pollution problems and 

developing a comprehensive program to achieve and maintain state and federal air quality 

standards.” A response time of 7 to 14 days for FRM data is unacceptable for fulfilling our 

mission statement to responsively monitor the air quality for the concern of the public’s 

health. 

VCAPCD proposes to progress to FEM hourly particulate sampling throughout its network. 

But we must do this cautiously with data analysis results to back-up and document our 

decision. VCAPCD is currently running a comparison of FRM to FEM data for both PM2.5

and PM10 for the calendar year 2013. PM2.5 FRM to PM2.5 FEM will be compared at the El 

Rio, Thousand Oaks, and Simi Valley stations. PM10 FRM to PM10 FEM will be compared at 

the El Rio and Simi Valley stations. We originally wanted to run this FRM to FEM 

comparison study in 2012, but sampler supply issues with the manufacturer delayed 

installation, and hence, a delay in the study by one year to 2013. 

Preliminary results of the comparison are quite good and match data shown in other 

comparisons by other agencies, specifically, and most recently, the April 7, 2011 EPA memo 

by Tim Hanley and Adam Reff, OAQPS titled “To assess the quality of recently approved 

PM2.5 continuous Federal Equivalent Method (FEM) data as operated in routine monitoring 

networks.”

EPA responded to our request for modifications to our particulate sampling network on 

February 11, 2012 (see Appendix F). EPA stated they approved of the “final PM2.5 network 

as outlined in the letter, if the study shows good agreement between the FRMs and FEMs.” 

In January and February 2014, we will run the comparisons and see if the results show good 

agreement. We will present the results with conclusions to EPA Region 9 and CARB. If the 

agreement between FRM and FEM is good, we will request to discontinue FRM operations. 

As noted in the conclusions of Hanley and Neff’s memo, if the results are not good, we will 

keep the PM2.5 FRM as the primary monitor while working towards improvements in FEM 

data quality.

3.1.3 Recent Changes to the Data Acquisition and Management System

Situations beyond our control hampered our ability to be productive and move forward with 

the change-over from our current data management system, ethernet data acquisition 

system (EDAS) to the new system (AirVision). EDAS is an old system and no longer 

supported by the manufacturer. EDAS has been in hourly use since 1997. Technology is 

advancing with data management systems and the data they acquire from the air quality 
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data analyzers at our air monitoring sites. Our goal is to use these advancements in 

technologies by having our Air Quality Technicians go into the field less often, and be able to 

work on the air quality analyzer in the field remotely from the VCAPCD office. This will 

improve staff productivity and reduce vehicle maintenance costs. VCAPCD has begun 

preparation and planning for the transition to AirVision. We anticipate having the transition 

to AirVision completed and the new system operational before the end of 2013.

3.1.4 Recent Changes to Laboratory Filter Processing Operations

In December 1998, we established a monitoring lab with an atmosphere-controlled filter 

room for processing our PM2.5 filters. In addition to our filters, we agreed to assist other air 

districts around the State by processing their PM2.5 filters. In early 2013, we had two 

contracts for processing particulate samples - with the San Joaquin Valley Air Pollution 

Control District (SJVAPCD) and CARB. 

The processing of PM2.5 filters requires controlled atmospheric conditions for pre- and postweighing. Even though our air conditioning unit is regularly maintained, it had been showing 

signs of age, and was having a very difficult time keeping the weighing room within 

operation specifications. In May 2013, the air conditioning unit appeared as if failure was 

imminent, and we could not guarantee the timely processing of PM2.5 filters for our clients. 

The replacement cost for the air conditioning unit is approximately $43,000. PM2.5

processing needs are being drastically reduced with the use of PM2.5 continuous samplers. 

Because of these issues, we reassessed whether a large financial expenditure for 

particulate sampling technology that is being phased out was a responsible use of funds. 

We decided it was not.

VCAPCD notified EPA, CARB, and SJVAPCD that we would not be able to process any 

more client PM2.5 filters. We completed processing the PM2.5 filters that we had received. 

CARB agreed to short term processing of PM2.5 filters until another lab could be found to 

process the filters. We sent filters and supplies to CARB to enable them to process filters, 

and CARB filter processing lab personnel worked extra shifts to respond to this immediate 

need. VCAPCD is very appreciative of the cooperation given to us, on such short notice, by 

CARB, SJVAPCD, and EPA Region 9 in addressing this issue. 

VCAPCD continues to process PM2.5 filters from VCAPCD monitoring sites.

3.1.5 Replacement of Analyzers and Equipment Since Last Reporting Period

In the interest of keeping up with technology and a desire to be proactive, we have an 

analyzer replacement schedule set up for the different analyzers, samplers, and calibration 
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equipment. Experience has shown that repairing aging and ailing analyzers reaches a point 

where it is no longer productive and, ultimately, is more costly than replacing the equipment. 

Our proactive analyzer replacement schedule minimizes data loss, providing VCAPCD and 

the public with timely air quality data. 

Ozone analyzers, FEMs, and calibration devices will be considered for replacement every 5 

years. NOx/NO/NO2 analyzers and data loggers will be considered for replacement every 8 

years. Meteorological equipment will be considered for replacement every 7 to 15 years. 

Uniformity of equipment throughout our network allows us to have a small stock of 

replacement parts that have an expected failure rate. These parts of our air monitoring 

network will be replaced as they fail. The equipment that fails will be replaced quickly due to 

a stock of replacement parts sufficient to meet a 6 month equipment failure projection.

Table 6 summarizes the analyzer and equipment replacement that has taken place at 

VCAPCD air monitoring sites since preparation of the 2012 Ambient Air Monitoring Network 

Plan.

Table 6 – Analyzer and Equipment Replacement – July 2012 to June 2013

Date(s) Equipment Event Notes

11/2012 –

01/2013 Flow calibration devices Purchased

Enables calibration of PM2.5 FEM and PM10 FEM 

continuous particulate samplers, and SASS sampler 

(operated for CARB)

01/2012 Trace NOy analyzer to 

continuous NO2 analyzer Converted

Converted from an unusable monitor from a 

discontinued program. One-fifth the cost of a new 

analyzer, saving VCAPCD $11,000.

01/2013 –

05/2013

Site computers –

all sites Purchased

Last replaced in 2006. Used to communicate, via 

the internet, between the VCAPCD office and site 

datalogger. These computers also allow us to 

communicate with the air quality analyzers and 

calibrators at the air monitoring sites.

01/2013 –

04/2013 Wind sensors Purchased

Replace RM Young Aerovane wind sensors with 

Climatronic wind sensors at El Rio and Simi Upper 

Air sites. All sites now equipped with Climatronic.

01/2013 –

04/2013

Temperature/humidity 

sensors

Purchased

Replaced all sites with Met One equipment. 

Temperature sensor life: 10 - 20 years, 

Hunidity sensor life: 5 – 10 years

05/2013

Calibrator for our 

gaseous air quality 

analyzers

Purchased Replace an ailing/aged calibrator at the El Rio site.

“ Ozone analyzer Ordered Old ozone analyzer will be used for parts for existing 

ozone analyzers.

“ NO2/NOx/NO analyzer Ordered Replace aged analyzer at the El Rio site.
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Table 6 – Analyzer and Equipment Replacement – July 2012 to June 2013 (cont’d)

Date(s) Equipment Event Notes

05/2013 PM2.5 FEM continuous 

particulate sampler Ordered Replace a very aged (2002) PM2.5 Beta Attenuation Monitor (BAM) at the Simi Valley site. 

“

FEM sampler probe 

inlets - raised Completed

In response to the early May 2013 CARB audits; to 

remove any question of roof safety railing 

interference or adjacent building proximity that may 

affect air flow to the probe inlet.

Fall 2013

(Estimated 

completion 

date)

Air inlet sampling lines Purchased

Associated with the replacement of gaseous air 

quality analyzers and calibrators; replaced due to 

deterioration and the requirement of higher flow 

rates of the new equipment

3.2 Network Operations – Post June 2013

This section describes proposed future changes for VCAPCD’s monitoring network.

3.2.1 Network Operations with No Proposed Changes

No changes are proposed for the ozone or the meteorological network during the remainder 

of this network plan reporting period.

3.2.2 Future Changes to the PM2.5 and PM10 Monitoring Network

In summer or fall of 2013, the PM2.5 non-FEM sampler will be replaced with a PM2.5 FEM 

sampler.

No additional changes are proposed for the PM2.5 or PM10 Monitoring Networks at this time. 

As noted in Section 3.1.2, Recent Changes to the PM2.5 and PM10 Monitoring Networks, 

should FRM and FEM show good agreement following review of 2013 data, in Spring 2014,

we will request to discontinue FRM operations. If agreement is not good, we will keep the 

FRMs as the primary monitors while working towards improvements in FEM data quality.

3.2.3 Future Changes to the Speciation Trends Network

The CSN was originally established in the early 1990’s to help determine the source of PM2.5

particles on days that exceeded the standard for those sites. Historically, many of the CSN

sites were located at PAMS monitoring sites.

With the future of the PAMS program in Ventura County uncertain due to EPA PAMS 

re-engineering efforts, VCAPCD anticipates evaluating the justification for continuing the 

CSN at the Simi Valley monitoring site in a future annual network plan, once the PAMS 
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re-engineering program details are finalized.

3.2.4 Future Changes - New NO2 Near-Road Monitoring Station

On February 9, 2010, EPA promulgated new minimum monitoring requirements for the NO2

Monitoring Network in support of a newly revised 1-hour NO2 NAAQS and the retained 

annual NAAQS. In the new monitoring requirements, state and local air monitoring

agencies are required to install Near-Road NO2 monitoring stations at locations where peak 

hourly NO2 concentrations are expected to occur within the Near-Road environment in 

larger urban areas. State and local air agencies are required to consider traffic volumes, 

fleet mix, roadway design, traffic congestion patterns, local terrain or topography, and 

meteorology in determining where a required Near-Road NO2 monitor should be placed. In 

40 CFR Part 58 Appendix D, the EPA requires state and local air agencies to operate one 

Near-Road NO2 monitor in any core-based statistical area (CBSA) with a population of

500,000 or more persons.

For site location requirements, 40 CFR Part 58, Appendix E states: “As near as practicable 

to the outside nearest edge of the traffic lanes of the target road segment; but shall not be 

located at a distance greater than 50 meters, in the horizontal, from the outside nearest 

edge of the traffic lanes of the target road segment.” In their Technical Assistance Document 

(TAD) for help with siting, EPA recommends that the target distance for near‐road NO2

monitor probes be within 20 meters of the target road whenever possible.

Preliminary results of traffic data indicate that the area with the highest traffic counts is the 

U.S. Highway (Hwy) 101 Freeway, east of the Hwy 101 and State Route (SR) 23

interchange. Our preliminary review of the meteorology of the area, and the other factors for 

considering site selection and location in the TAD (Near-Road NO2 Monitoring Technical 

Assistance Document, EPA-454/B-12-002, June 2012) indicates that a possible site location 

could be on the dirt median, on the north side of Hwy 101, at approximately 3600 

Duesenberg Drive, Thousand Oaks, California (N34.161889, W-118.830872).

In October 2012, EPA proposed a revision to the Near-Road NO2 monitoring requirement of 

site establishment by January 1, 2013. The EPA proposal, Revision to Ambient Nitrogen 

Dioxide Monitoring Requirements (proposed revision), was published in the Federal 

Register on October 19, 2012 (77 Federal Register 64244). The proposed revision states

that a Near-Road NO2 monitoring site would be required in each CBSA with a population 

more than 500,000, but less than 1 million, by January 1, 2017. Ventura County has a 

population of approximately 823,318 (as of 2010 census); hence only one Near-Road NO2

site would be required to be operational by January 1, 2017.

Site acquisition and permission is the first step for the Near-Road NO2 monitoring site. We 
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will begin discussions for site location permission with Caltrans, EPA, CARB, and the City of 

Thousand Oaks in 2015. In 2015, we will also begin the process of hiring an Air Quality 

Instrument Technician to help assist with the additional workload, and begin the learning 

curve on air quality instrumentation operation and maintenance. As noted in Table 7, we are 

planning on the procurement of equipment and personnel in 2015, provided EPA funding 

assistance. Equipment would be delivered in early 2016, and testing would begin in Spring 

2016. Once permission for establishment of a site is obtained, we will begin construction of 

the air monitoring site during the Summer 2016. By Fall 2016, the site will begin operational 

testing of equipment and systems. On January 1, 2017, our Near-Road NO2 air monitoring 

site in Thousand Oaks, California will officially begin collecting and reporting data.

3.2.5 Future Changes to the PAMS Network

VCAPCD has three PAMS air quality monitoring sites. El Rio is a site Type 2 (maximum 

precursor emission site), Simi Valley is a site Type 3 (maximum ozone concentration site), 

and Simi Upper Air is a Type 3 support site for collecting meteorological atmospheric 

structure data. The El Rio and Simi Valley sites collect canisters on a 1-in-3 day schedule 

during July, August, and September, pursuant to the California Alternative Plan III.

In May 2012, VCAPCD staff attended the EPA National Air Quality Conference in Denver, 

Colorado. At that conference, Kevin Cavender (EPA) presented “PAMS Re-Engineering”. 

As part of that presentation, EPA proposed to decrease the number of PAMS sites from 52 

to a future 26. Ventura County was a county listed as not having a PAMS monitoring site in 

the future. Additionally, an April 28, 2011 email from EPA Region 9 contact, Meredith 

Kurpius, cautioned us on changing any part of our PAMS monitoring program due to the 

possibility of the discontinuation of the program in Ventura County, at least until the EPA’s 

PAMS re-engineering is finalized.

Continuous TNMOC monitoring is required at site Types 2 and 3. Our TNMOC analyzers at 

the El Rio and Simi Valley sites failed in 2010. In an effort to monitor ozone precursors, we 

installed and made operational the TNMOC analyzer at Simi Valley in April 2012. The El 

Rio site TNMOC analyzer has not been installed, because, as stated above, our PAMS 

network is on hold and we are not to make any changes to our existing PAMS network until 

after the EPA updates PAMS requirements. 

In December 2012, at the Simi Valley Type 3 site, our hydrogen generator began to fail, and 

in January 2013, our hydrocarbon analyzer began to fail. Both pieces of equipment failed in 

April 2013. The replacement of this equipment would cost VCAPCD approximately 

$11,000, plus staff time, and an ongoing operational specialty gas usage cost of $400 per 

month. Due to the continued improvements in air quality and uncertainty of the value/need 

to identify ozone precursors at the Simi Valley site, VCAPCD questioned large financial 
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20 VENTURA COUNTY APCD MONITORING DIVISION

expenditures for a project that may be cancelled in the near future, and the value of the data 

for historical correlation to ozone formation. With permission to not replace the hydrocarbon 

equipment given via email from EPA-Region 9 Meredith Kurpius and EPA’s Kevin 

Cavender, VCAPCD chose not to replace the equipment, and wait until the EPA’s PAMS reengineering is finalized. A letter formally requesting discontinuation of collection of 

continuous hydrocarbon data at the Simi Valley site is included in Appendix F.

The atmospheric profiler in Simi Valley (Simi Upper Air site) had been a very useful tool in 

determining lower atmosphere winds and temperature structure from the surface up to 2 

kilometers. The atmospheric profiler became operational in July 1995 and continued 

operation until November 2010. The atmospheric profiler was designed to last about 5 

years. But with upgrades and staff know-how, we were able to keep the atmospheric 

profiler running for many years past its design life. But in November 2010, we could no 

longer repair the computer and associated hardware. 

In April 2011, we found a company that could rebuild our atmospheric profiler. In May 2012, 

that company installed the upgraded components, which made the atmospheric profiler 

operational again. But, the profiler upgrade failed soon after, working for short periods of 

time, as the atmospheric profiler upgrade company tried to make the profiler work. But after 

nearly 9 months of poor performance, VCAPCD stopped the project in January 2013. The 

atmospheric profiler failed to work for even a week at a time during those 9 months. We are 

now (June 2013) in talks with the upgrade company to fix the atmospheric profiler or refund

the upgrade costs.

40 CFR 58 Appendix D, Section 5 specifies the network design for the PAMS program. 

Federal regulations require the addition of reactive nitrogen compounds (NOy) monitoring at 

Type 3 sites (Simi Valley) and trace carbon monoxide (CO) monitoring at Type 2 sites (El 

Rio). We have not installed the instrumentation due to widespread questioning by Federal 

and state air agency staff of the rationale of monitoring NOy and trace CO in Southern 

California. 

Our gas chromatograph and carbonyl sampler are aged and are being kept operational 

even though they have exceeded their design life. We are keeping them operational, 

repairing/replacing parts that fail, until we hear further about the re-engineering requirements 

of PAMS. 

3.2.6 Future Changes to the Data Acquisition and Management System

As described in Section 3.1.3, Recent Changes to the Data Acquisition and Management 

System, VCAPCD is beginning the transition from EDAS to AirVision, and anticipates 

completion of the project by the end of 2013.
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3.2.7 Future Replacement of Analyzers and Equipment

In an effort to save staff time and maintain data collection objectives, VCAPCD has an 

equipment replacement schedule set up to replace our old equipment as it begins to fail, and 

a cost/benefit analysis shows that equipment replacement is more prudent that equipment 

repair. Table 7 is the anticipated analyzer and equipment replacement schedule for the next 

few fiscal years. This schedule is updated on an as-needed basis; if current equipment 

continues to function well, then replacement dates are postponed.

Table 7 – Analyzer and Equipment Replacement – Post June 2013

Date(s) Equipment Event Notes

FY 2013/2014 Two ozone analyzers Planned

“ One air quality analyzer calibrator Planned

“ One zero air generator Planned

“ One PM2.5 FRM sampler Planned

“ One PM2.5 FEM sampler Planned

FY 2014/2015 Two ozone analyzers Planned

One PM10 FRM sampler Planned

FY 2015/2016 One ozone analyzer Planned

“ One air quality analyzer calibrator Planned

“ One PM2.5 FRM sampler Planned

“ Two PM2.5 FEM samplers Planned

“ Two PM10 FEM samplers Planned

“ One flow calibrator Planned For air quality gaseous analyzers

“ Glass sample trains Planned

Mid/Late 2015 Equipment for new Near-Road

NO2 monitor Planned

Specific equipment unknown (as of June 

2013). Begin purchase and preparation 

for setup and testing at new site.

FY 2016/2017 One ozone analyzer Planned

“ Two PM2.5 FEM samplers Planned

“ One NO2/NOx/NO analyzer Planned

“

Equipment for new Near-Road

NO2 monitor - finalize Planned

Specific equipment unknown (as of June 

2013). Complete acquisition and 

installation of equipment for new site.

FY 2017/2018 One ozone analyzer Planned

“

Site computers –

all sites Planned

Only if needed - technological 

improvements of air quality analyzers 

may make use of computers obsolete.

“

AirVision data management 

computer Planned For VCAPCD office
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A-1 VENTURA COUNTY APCD MONITORING DIVISION

Appendix A 2013 ANNUAL AIR MONITORING NETWORK PLAN CHECKLIST

The VCAPCD has included this appendix in an effort to clearly communicate the location of information required as part of Annual 

Monitoring Network Plans per 40 CFR 58. Table 8 is taken from the 2013 Annual Air Monitoring Network Plan Checklist, provided 

to Kent Field, Monitoring Division Manager, VCAPCD, by Meredith Kurpius, PhD., Air Quality Analysis Office, Air Monitoring Team 

Lead, EPA Region 9. District staff replaced the column “Was the info submitted? If yes, page #s. Flag if incorrect?” in the original 

checklist with “Location of submitted info.” Otherwise, the content of the table is the same as the original checklist received by Dr 

Kurpius.
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A-2 VENTURA COUNTY APCD MONITORING DIVISION

Table 8 – Location of Submitted Information – 2013 Ambient Air Monitoring Network Plan

ANP requirement

Citation 

within 40 

CFR 58

Location of 

submitted info

Does the 

information 

provided meet 

the req? Notes 

1. Submit plan by July 1st 58.10 (a)(1) Submittal letter

2. Statement of purpose for each monitor 58.10 (a)(1) Section 2.1 and 

Appendix B

[Yes if correct info 

was submitted]

3. 30-day public comment / inspection period 58.10 (a)(1), 

58.10 (a)(2) Section 1

4. Modifications to SLAMS network – case when we 

are not approving actual system modifications (i.e., 

we will do it outside the ANP process)

58.10 (a)(2) 

58.10(e) Appendix F [Yes if correct info 

was submitted]

5. Modifications to SLAMS network – case when we 

are approving actual system modifications per 

58.14(c)

58.10 (a)(2)

58.10 (b)(5)

58.10(e)

58.14 (c)

Appendix F

[Yes if correct info 

was submitted and 

58.14(c) has been 

met]

6. Does plan include documentation (e.g., attached 

approval letter) for system modifications that have 

been approved since last ANP approval?

Appendix F [Yes if correct info 

was submitted]

7. NCore site operational (by 1/1/2011) 58.10 (a)(3) Appendix C (NA)

8. Pb site for 0.5-1.0 tpy sources operational (by 

12/27/2011) 58.10 (a)(4) Appendix C (NA)

9. NO2 plan for area-wide and RA40 sites submitted 

by 7/1/2012 58.10 (a)(5) Appendix C (NA)

10. NO2 area-wide and RA40 sites operational by 

1/1/2013 58.10 (a)(5) Appendix C (NA)

11. NO2 plan for Near-Road sites submitted by 

7/1/2013 58.10 (a)(5) Appendix C (NA)

12. SO2 sites operational (by 1/1/2013) 58.10 (a)(6) 

and 58.13(d) Appendix C (NA)

13. AQS site identification number for each site 58.10 (b)(1) Table 1 and

Appendix B

[Yes if correct info 

was submitted]
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A-3 VENTURA COUNTY APCD MONITORING DIVISION

Table 8 – Location of Submitted Information – 2013 Ambient Air Monitoring Network Plan (cont’d)

ANP requirement

Citation 

within 40 

CFR 58

Location of 

submitted info

Does the 

information 

provided meet 

the req? Notes 

14. Location of each site: street address and 

geographic coordinates 58.10 (b)(2) Appendix B [Yes if correct info was submitted]

15. Sampling and analysis method(s) for each 

measured parameter 58.10 (b)(3) Appendix B

16. Any proposals to remove or move a monitoring 

station within a period of 18 months following plan 

submittal 58.10 (b)(5) NA

[Yes if correct info 

was submitted, 

(assumes we are 

not approving the 

changes in ANP)]

17 Scale of representativeness for each monitor as 

defined in Appendix D

58.10(b)(6); 

App D Appendix B

18. Identification of sites suitable and sites not suitable 

for comparison to the annual PM2.5 NAAQS as 

described in Part 58.30

58.10 (b)(7) Appendix B

19. MSA, CBSA, CSA or other area represented by the 

monitor 58.10 (b)(8) Appendix B [Yes if correct info was submitted]

20. Designation of any Pb monitors as either sourceoriented or non-source-oriented 58.10 (b)(9) Appendix C (NA) [Yes if correct info 

was submitted]

21. Any source-oriented Pb site for which a waiver has 

been granted by EPA RA 58.10 (b)(10) Appendix C (NA) [Yes if correct info was submitted]

22. Any Pb monitor for which a waiver has been 

requested or granted by EPA RA for us of Pb-PM10 

in lieu of Pb-TSP

58.10 (b)(11) Appendix C (NA) [Yes if correct info 

was submitted]

23. Identification of required NO2 monitors as either 

Near-Road or area-wide 58.10 (b)(12) Table 1 and

Appendix C
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A-4 VENTURA COUNTY APCD MONITORING DIVISION

Table 8 – Location of Submitted Information – 2013 Ambient Air Monitoring Network Plan (cont’d)

ANP requirement

Citation 

within 40 

CFR 58

Location of 

submitted info

Does the 

information 

provided meet 

the req? Notes 

24. Identification of any PM2.5 FEMs and/or ARMs not 

eligible to be compared to the NAAQS (Note 1: 

must include required data assessment.) (Note 2: 

Required SLAMS must monitor PM2.5 with 

NAAQS-comparable monitor at the required sample 

frequency.)

58.10 (b)(13)

58.11 (e)

NA

25. For SPMs listed as non-regulatory, note the start 

Date of FRM/FEM/ARM at SPM. If > 24 months, 

and monitor is eligible for comparison to the NAAQS 

per 58.11 (e) and 58.30, the agency must supply 

information that App A, C or E requirements were 

not met.

58.20(c) NA

26. Document how states and local agencies provide 

for the review of changes to a PM2.5 monitoring 

network that impact the location of a violating PM2.5 

monitor.

58.10 (c) Appendix C [Yes if correct info 

was submitted]

27. Does the plan include a request for approval for and 

alternative to appendix A requirements for SPMs 

operating a FRM/FEM/ARM which also meets 

appendix E?

58.11 (a) (2) NA

28. Precision/Accuracy reports submitted to AQS 58.16(a);

App A, 1.3 

and 5.1.1

Appendix B

29. Annual data certification submitted 58.15

App. A 1.3 Section 2.4

30. Frequency of flow rate verification for manual PM 

samplers audit App A 3.3.2 Appendix B
AMBIENT AIR MONITORING NETWORK PLAN 2013

A-5 VENTURA COUNTY APCD MONITORING DIVISION

Table 8 – Location of Submitted Information – 2013 Ambient Air Monitoring Network Plan (cont’d)

ANP requirement

Citation 

within 40 

CFR 58

Location of 

submitted info

Does the 

information 

provided meet 

the req? Notes 

31. Frequency of flow rate verification for automated 

PM analyzers audit App A 3.2.3 Appendix B

32. Frequency of one-point flow rate verification for Pb 

samplers audit

App A 

3.3.4.1 NA

33. Frequency of one-point QC check (gaseous) App. A 3.2.1 Appendix B

34. Date of last Annual Performance Evaluation 

(gaseous) App. A 3.2.2 Appendix B

35. Dates of last two semi-annual flow rate audits for 

PM monitors

App A, 3.2.4 

and 3.3.3 Appendix B

36. Dates of last two semi-annual flow rate audits for Pb 

monitors

App A 

3.3.4.1 NA

37. PM2.5 co-location App A 3.2.5 Appendix E

38. Designation of a primary monitor if there is more 

than one monitor for a pollutant at a site.

Need to 

determine 

collocation

Appendix B

39. Distance between co-located monitors (Note:

waiver request or the date of previous waiver 

approval must be included if the distance deviates 

from requirement.)

App. A 

3.2.5.6 and 

3.2.6.3

Appendix B

40. Manual PM10 method co-location met? (note: 

continuous PM10 does not have this requirement) App A 3.3.1 Appendix B and Appendix E

41. Pb co-location App A 

3.3.4.3 Appendix E (NA)

42. PM10-2.5 co-location (note: only applies to Fresno 

and Phoenix NCore sites) App A 3.3.6 Appendix E (NA)
AMBIENT AIR MONITORING NETWORK PLAN 2013

A-6 VENTURA COUNTY APCD MONITORING DIVISION

Table 8 – Location of Submitted Information – 2013 Ambient Air Monitoring Network Plan (cont’d)

ANP requirement

Citation 

within 40 

CFR 58

Location of 

submitted info

Does the 

information 

provided meet 

the req? Notes 

43. Instrument/monitoring method code for each 

monitor: is it reported properly? Is it reported 

correctly (i.e., appropriate method code for 

regulatory monitors)?

App C 

2.4.1.2 Appendix B

44. For agencies that share monitoring responsibilities 

in an MSA/CSA: does each affected State or local 

agency meet full monitoring requirements or is an 

agreement between the affected agencies and the 

EPA Regional Administrator in place?

App D 2(e) Section 2.3.3

45. Start date for each monitor Required to 

determine if 

other req. 

(e.g., min # 

and co-lo) 

are met

Appendix B [Yes if correct info 

was submitted]

46. Instrument monitor type for each monitor Required to 

determine if 

other req. 

(e.g., min # 

and co-lo) 

are met

Appendix B [Yes if correct info 

was submitted]

47. Monitoring objective for each instrument App D 1.1

58.10 (b)(6) Appendix B [Yes if correct info was submitted]

48. Site type for each instrument App D 1.1.1 Appendix B [Yes if correct info 

was submitted]
AMBIENT AIR MONITORING NETWORK PLAN 2013

A-7 VENTURA COUNTY APCD MONITORING DIVISION

Table 8 – Location of Submitted Information – 2013 Ambient Air Monitoring Network Plan (cont’d)

ANP requirement

Citation 

within 40 

CFR 58

Location of 

submitted info

Does the 

information 

provided meet 

the req? Notes 

49. Instrument parameter code for each instrument Required to 

determine if 

other req. 

(e.g., min # 

and co-lo) 

are met

Appendix B [Yes if correct info 

was submitted]

50. Instrument parameter occurrence code for each 

instrument

Required to 

determine if 

other req. 

(e.g., min # 

and co-lo) 

are met

Appendix B [Yes if correct info 

was submitted]

51. Sampling season for ozone (note: date of waiver 

approval must be included if the sampling season 

deviates from requirement)

58.10 (b)(4)

App D, 4.1(i) Appendix B

52. Sampling schedule for PM2.5 - applies to yearround and seasonal sampling schedules (note: date 

of waiver approval must be included if the sampling 

season deviates from requirement) 

58.10 (b)(4)

58.12(d)

App D 4.7

EPA 

flowchart

Appendix B

53. Sampling schedule for PM10 58.10 (b)(4)

58.12(e)

App D 4.6

Appendix B

54. Sampling schedule for Pb 58.10 (b)(4)

58.12(b)

App D 4.5

NA
AMBIENT AIR MONITORING NETWORK PLAN 2013

A-8 VENTURA COUNTY APCD MONITORING DIVISION

Table 8 – Location of Submitted Information – 2013 Ambient Air Monitoring Network Plan (cont’d)

ANP requirement

Citation 

within 40 

CFR 58

Location of 

submitted info

Does the 

information 

provided meet 

the req? Notes 

55. Sampling schedule for PM10-2.5 58.10 (b)(4)

58.12(f)

App D 4.8

NA

56. Minimum # of monitors for O3[Note: should be 

supported by MSA ID, MSA population, DV, # 

monitors, and # required monitors]

App D, 4.1(a) 

and 

Table D-2

Appendix C

57. Identification of max. conc. O3 monitor(s) App D 4.1 (b) Section 2.3.1

58. Minimum monitoring requirements met for NearRoad NO2 (2014 start date) App D 4.3.2 Appendix C

59. Minimum monitoring requirements met for areawide NO2 App D 4.3.3 Appendix C

60. Minimum monitoring requirements met for RA-40 

NO2 App D 4.3.4 Appendix C (NA)

61. Minimum monitoring requirements met for SO2 

[Note: Only monitors considered to be required 

SLAMs are eligible to be counted towards meeting 

minimum monitoring requirements.]

App D 4.4 Appendix C (NA)

62. Minimum monitoring requirements met for Pb [Note: 

Only monitors considered to be required SLAMs are 

eligible to be counted towards meeting minimum 

monitoring requirements.]

App D 4.5 

58.13(a) Appendix C (NA)

63. Minimum # of monitors for PM2.5 [Note 1: should 

be supported by MSA ID, MSA population, DV, # 

monitors, and # required monitors] [Note 2: Only 

monitors considered to be required SLAMs are 

eligible to be counted towards meeting minimum 

monitoring requirements.]

App D,

4.7.1(a) and 

Table D-5

Appendix C
AMBIENT AIR MONITORING NETWORK PLAN 2013

A-9 VENTURA COUNTY APCD MONITORING DIVISION

Table 8 – Location of Submitted Information – 2013 Ambient Air Monitoring Network Plan (cont’d)

ANP requirement

Citation 

within 40 

CFR 58

Location of 

submitted info

Does the 

information 

provided meet 

the req? Notes 

64. Optional PM2.5 Network Clarifications: Provide a list 

of required sites if it does not include all SLAMS. 

[Note: default will assume all SLAMS are 

considered required sites.]

Need to 

assess 

several 

requirements

Sections

2.3.2 – 2.3.4

65. Required PM2.5 sites represent area-wide air 

quality

App D

4.7.1(b) Table 3

66. For PM2.5, is at least one site at neighborhood or 

larger scale in an area of expected maximum 

concentration

App D

4.7.1(b)(1)

Table 3 and

Appendix B

67. If additional SLAMS PM2.5 required, is there a site 

in an area of poor air quality

App D

4.7.1(b)(2) NA

68. Minimum monitoring requirements for continuous 

PM2.5 App D 4.7.2 Appendix C

69. Requirements for PM2.5 background and transport 

sites App D 4.7.3 NA

70. Are PM2.5 Chemical Speciation requirements met 

for official STN sites? App D 4.7.4 Section 2.3.3

71. Minimum # of monitors for PM10 App D, 4.6 

(a) and Table 

D-4 

Appendix C

72. Minimum monitoring requirements met for PM10-

2.5 mass

App D 4.8 Appendix C (NA)

73. Distance of site from nearest road App E 6 Appendix B

74. Traffic count of nearest road App E Appendix B

75. Groundcover App E 3(a) Appendix B

76. Probe height App E 2 Appendix B

77. Distance from supporting structure App E 2 Appendix B
AMBIENT AIR MONITORING NETWORK PLAN 2013

A-10 VENTURA COUNTY APCD MONITORING DIVISION

Table 8 – Location of Submitted Information – 2013 Ambient Air Monitoring Network Plan (cont’d)

ANP requirement

Citation 

within 40 

CFR 58

Location of 

submitted info

Does the 

information 

provided meet 

the req? Notes 

78. Distance from obstructions on roof App E 4(b) Appendix B

79. Distance from obstructions not on roof App E 4(a) Appendix B

80. Distance from trees App E 5 Appendix B

81. Distance to furnace or incinerator flue App E 3(b) Appendix B

82. Unrestricted airflow App E, 4(a) 

and 4(b) Appendix B

83. Probe material (if applicable) App E 9 Appendix B

84. Residence time (if applicable) App E 9 Appendix B

Public Comments on Annual Network Plan

Were comments submitted to the S/L/T agency during the public comment period? 

If no, skip the remaining questions.

If yes:

 Were any of the comments substantive?

o If yes, which ones? 

o Explain basis for determination if any comments were considered not substantive:

 Did the agency respond to the substantive comments?

o If yes, was the response adequate?

 Do the substantive comments require separate EPA response (i.e., agency response wasn’t adequate)?

 Are the sections of the annual network plan that received substantive comments approvable after consideration of comments?

o If yes, provide rationale:
AMBIENT AIR MONITORING NETWORK PLAN 2013

B-1 VENTURA COUNTY APCD MONITORING DIVISION

Appendix B Detailed Station Information

This appendix presents detailed site information the reporting of which is required by federal 

regulation.

Table 9 – El Rio Station Information

Local Site Name > El Rio – Rio Mesa School #2

AQS ID 061113001

GPS coordinates 34.25238, -119.14318

Street address 545 Central Ave, Oxnard CA 93030

County Ventura County

Distance to roadways 101 meters

Traffic count 5,000 vehicles/day, 2013

Groundcover Paved/Asphalt

Representative statistical 

area name

Oxnard-Thousand Oaks-Ventura 

Metro Area

Pollutant, POC > Ozone, 1 NO2, 1 PM2.5FEM, 3 PM 2.5 FRM, 1

Parameter code 44201 42602 88101 88101

Basic monitoring objective NAAQS NAAQS NAAQS NAAQS

Site type Population 

Exposure

Population 

Exposure

Population 

Exposure

Population 

Exposure

Monitor type SLAMS, PAMS PAMS SLAMS SLAMS

Instrument manufacturer and 

model API Model 400 API Model 200 Met One BAM1020

Thermo Fischer 

Scientific 2025 

Seq.

Method code 087 082 170 118

Primary monitor Yes Yes No Yes

FRM/FEM/ARM/other FRM FRM FEM FRM

Collecting agency VCAPCD VCAPCD VCAPCD VCAPCD

Analytical lab NA NA NA NA

Reporting agency VCAPCD VCAPCD VCAPCD VCAPCD

Spatial scale Urban Urban Neighborhood Neighborhood

Monitoring start date 01/01/1979 01/01/1980 01/26/2012 01/01/1999

Current sampling frequency Continuous Continuous Continuous 1-in-6 days

Calculated sampling frequency NA NA NA NA

Sampling season Year-round Year-round Year-round Year-round

Probe height 4.3 meters 4.3 meters 4.6 meters 5.8 meters

Distance from supporting 

structure 1.2 meters 1.2 meters 1.7 meters 2.2 meters

Distance from obstructions on 

roof None None None None
AMBIENT AIR MONITORING NETWORK PLAN 2013

B-2 VENTURA COUNTY APCD MONITORING DIVISION

Table 9 – El Rio Station Information (cont’d)

Pollutant, POC > Ozone, 1 NO2, 1 PM2.5FEM, 3 PM 2.5 FRM, 1

Distance from obstructions not 

on roof None None None None

Distance from trees 25 meters 25 meters 29 meters 27 meters

Distance to furnace or 

incinerator flue NA NA NA NA

Distance between collocated 

monitors NA NA NA NA

Unrestricted airflow 360 degrees 360 degrees 360 degrees 360 degrees

Probe material for reactive 

gases

Borosilicate 

glass & FEP 

Teflon

Borosilicate 

glass & FEP 

Teflon

NA NA

Residence time for reactive 

gases

7.5 seconds 8.8 seconds NA NA

Will there be changes within the 

next 18 months? No No No

Maybe

see Section 

3.1.2

Is it suitable for comparison 

against the annual PM2.5

NAAQS?

NA NA Yes Yes

Frequency of flow rate 

verification for manual PM 

samplers

NA NA NA 1x/month flow

2x/month leak

Frequency of flow rate 

verification for automated PM 

analyzers

NA NA

2x/month 

flow and leak 

check

NA

Frequency of one-point QC 

check for gaseous instruments Weekly Weekly NA NA

Last Annual Performance 

Evaluation for gaseous 

parameters

04/30/2013 04/30/2013 NA NA

Last two semi-annual flow rate 

audits for PM monitors NA NA 11/07/201204/30/2013

11/07/2012

04/30/2013
AMBIENT AIR MONITORING NETWORK PLAN 2013

B-3 VENTURA COUNTY APCD MONITORING DIVISION

Table 9 – El Rio Station Information (cont’d)

Local Site Name > El Rio – Rio Mesa School #2

AQS ID 061113001

GPS coordinates 34.25238, -119.14318

Street address 545 Central Ave, Oxnard CA 93030

County Ventura County

Distance to roadways 101 meters

Traffic count 5,000 vehicles/day, 2013

Groundcover Paved/Asphalt

Representative statistical 

area name

Oxnard-Thousand Oaks-Ventura 

Metro Area

Pollutant, POC > PM10FEM, 3 PM10 FRM, 1 VOCs, 1 Carbonyls, 1

Parameter code 81102 81102 NA

43502

43503

43551

Basic monitoring objective NAAQS NAAQS Research Research

Site type

Population 

exposure

Population 

exposure

Maximum 

Precursor 

Emissions 

Impact

Maximum 

Precursor 

Emissions 

Impact

Monitor type SLAMS SLAMS PAMS PAMS

Instrument manufacturer and 

model

Met One BAM 

1020 GMW 1200 Varian 3800 Atec Model 800

Method code 122 063 123 102

Primary monitor No Yes Yes Yes

FRM/FEM/ARM/other FEM FRM Other Other

Collecting agency VCAPCD VCAPCD VCAPCD VCAPCD

Analytical lab NA NA VCAPCD

Atmospheric 

Analysis & 

Consulting

Reporting agency VCAPCD VCAPCD VCAPCD VCAPCD

Spatial scale Neighborhood Neighborhood Neighborhood Urban

Monitoring start date 07/22/2012 04/03/1988 06/01/1994 06/01/1995

Current sampling frequency Continuous 1-in-6 days

1-in-3 days and 

days in which 

ozone is 

predicted to 

exceed .075 ppm

1-in-3 days and 

days in which 

ozone is 

predicted to 

exceed .075 

ppm

Calculated sampling frequency NA NA NA NA

Sampling season Year-round Year-round July 1 through 

September 30

July 1 through 

September 30

Probe height 4.5 meters 5.2 meters 4.3 meters 5.0 meters
AMBIENT AIR MONITORING NETWORK PLAN 2013

B-4 VENTURA COUNTY APCD MONITORING DIVISION

Table 9 – El Rio Station Information (cont’d)

Pollutant, POC > PM10FEM, 3 PM10 FRM, 1 VOCs, 1 Carbonyls, 1

Distance from supporting 

structure 1.6 meters 1.6 meters 1.2 meters 1.5 meters

Distance from obstructions on 

roof None None None None

Distance from obstructions not 

on roof None None None None

Distance from trees 29 meters 28 meters 29 meters 30 meters

Distance to furnace or 

incinerator flue NA NA NA NA

Distance between collocated 

monitors NA NA NA NA

Unrestricted airflow 360 degrees 360 degrees 360 degrees 360 degrees

Probe material for reactive 

gases

NA NA

Borosilicate 

glass & FEP 

Teflon

NA

Residence time for reactive 

gases

NA NA NA Maybe

Will there be changes within 

the next 18 months? No Yes

Maybe, 

awaiting EPA 

decision

NA

Is it suitable for comparison 

against the annual PM2.5

NAAQS?

NA NA NA NA

Frequency of flow rate 

verification for manual PM 

samplers

NA 1x/month

flow NA NA

Frequency of flow rate 

verification for automated PM 

analyzers

2x/month 

flow and leak 

check

NA NA NA

Frequency of one-point QC 

check for gaseous instruments NA NA 2x/smog season,June & October NA

Last Annual Performance 

Evaluation for gaseous 

parameters

NA NA 2011 NA

Last two semi-annual flow rate 

audits for PM monitors

11/07/2012

04/30/2013

11/07/2012

04/30/2013 NA NA
AMBIENT AIR MONITORING NETWORK PLAN 2013

B-5 VENTURA COUNTY APCD MONITORING DIVISION

Table 10 – Ojai Station Information

Local Site Name > Ojai - Ojai Avenue

AQS ID 061111004

GPS coordinates 34.44804,-119.23131

Street address 1201 Ojai Ave., Ojai CA 93023

County Ventura County

Distance to roadways 65 meters

Traffic count 7,300 vehicles/day, 2011

Groundcover Paved

Representative statistical 

area name

Oxnard-Thousand Oaks-Ventura 

Metro Area

Pollutant, POC > Ozone, 1 PM2.5 FEM, 3

Parameter code 44201 88101

Basic monitoring objective NAAQS NAAQS

Site type Population exposure Population exposure

Monitor type SLAMS SLAMS

Instrument manufacturer and 

model API Model 400 Met One BAM 1020

Method code 087 170

Primary monitor Yes Yes

FRM/FEM/ARM/other FRM FEM

Collecting agency VCAPCD VCAPCD

Analytical lab NA NA

Reporting agency VCAPCD VCAPCD

Spatial scale Urban Neighborhood

Monitoring start date 04/01/1996 11/29/2011

Current sampling frequency Continuous Continuous

Calculated sampling frequency NA NA

Sampling season Year-round Year-round

Probe height 4.0 meters 4.6 meters

Distance from supporting 

structure 1.5 meters 1.5 meters

Distance from obstructions on 

roof None None

Distance from obstructions not 

on roof None None

Distance from trees 35 meters 33 meters

Distance to furnace or incinerator 

flue NA NA

Distance between collocated 

monitors NA NA

Unrestricted airflow 360 degrees 360 degrees
AMBIENT AIR MONITORING NETWORK PLAN 2013

B-6 VENTURA COUNTY APCD MONITORING DIVISION

Table 10 – Ojai Station Information (cont’d)

Pollutant, POC > Ozone, 1 PM2.5FEM, 3

Probe material for reactive 

gases

Borosilicate glass & FEP Teflon NA

Residence time for reactive 

gases

8.5 seconds NA

Will there be changes within the 

next 18 months? No No

Is it suitable for comparison 

against the annual PM2.5

NAAQS?

NA Yes

Frequency of flow rate 

verification for manual PM 

samplers

NA NA

Frequency of flow rate 

verification for automated PM 

analyzers

NA 2x/month

flow and leak check

Frequency of one-point QC 

check for gaseous instruments Weekly NA

Last Annual Performance 

Evaluation for gaseous 

parameters

05/02/2013 NA

Last two semi-annual flow rate 

audits for PM monitors NA 11/07/201205/02/2012
AMBIENT AIR MONITORING NETWORK PLAN 2013

B-7 VENTURA COUNTY APCD MONITORING DIVISION

Table 11 – Piru Station Information

Local Site Name > Piru – Pacific Avenue

AQS ID 061110009

GPS coordinates 34.40426, -118.80991

Street address 3301 Pacific Ave., Piru CA 93040

County Ventura County

Distance to roadways 382 meters

Traffic count 23,000 vehicles/day, 2011

Groundcover Gravel

Representative statistical 

area name

Oxnard-Thousand Oaks-Ventura 

Metro Area

Pollutant, POC > Ozone, 1 PM2.5 FEM, 3

Parameter code 44201 88101

Basic monitoring objective NAAQS NAAQS

Site type Population exposure Population exposure

Monitor type SLAMS SLAMS

Instrument manufacturer and 

model API Model 400 Met One BAM 1020

Method code 087 170

Primary monitor Yes Yes

FRM/FEM/ARM/other FRM FEM

Collecting agency VCAPCD VCAPCD

Analytical lab NA NA

Reporting agency VCAPCD VCAPCD

Spatial scale Urban Neighborhood

Monitoring start date 11/03/2000 11/15/2011

Current sampling frequency Continuous Continuous

Calculated sampling frequency NA NA

Sampling season Year-round Year-round

Probe height 3.5 meters 4.6 meters

Distance from supporting structure 1.0 meters 2.0 meters

Distance from obstructions on roof None None

Distance from obstructions not on 

roof None None

Distance from trees 30 meters 29 meters

Distance to furnace or incinerator 

flue NA NA

Distance between collocated 

monitors NA NA

Unrestricted airflow 360 degrees 360 degrees

Probe material for reactive gases Borosilicate glass & FEP Teflon NA

Residence time for reactive gases 9.9 seconds NA
AMBIENT AIR MONITORING NETWORK PLAN 2013

B-8 VENTURA COUNTY APCD MONITORING DIVISION

Table 11 – Piru Station Information (cont’d)

Pollutant, POC > Ozone, 1 PM2.5 FEM, 3

Will there be changes within the 

next 18 months? No No

Is it suitable for comparison 

against the annual PM2.5 NAAQS? NA Yes

Frequency of flow rate verification 

for manual PM samplers NA NA

Frequency of flow rate verification 

for automated PM analyzers NA 2x/monthflow and leak check

Frequency of one-point QC check 

for gaseous instruments Weekly NA

Last Annual Performance 

Evaluation for gaseous parameters 05/20/2013 NA

Last two semi-annual flow rate 

audits for PM monitors NA 11/07/201205/20/2013
AMBIENT AIR MONITORING NETWORK PLAN 2013

B-9 VENTURA COUNTY APCD MONITORING DIVISION

Table 12 – Simi Valley Station Information

Local Site Name > Simi Valley – Cochran Street

AQS ID 061112002

GPS coordinates 34.27640, -118.68375

Street address 5400 Cochran St., Simi Valley CA 93063

County Ventura County

Distance to roadways 278 meters

Traffic count 10,200 vehicles/day, 2013

Groundcover Asphalt

Representative statistical 

area name

Oxnard-Thousand Oaks-Ventura 

Metro Area

Pollutant, POC > Ozone,1 NO2, 1 PM2.5 FRM, 1

PM2.5 

Non-FEM, 3

Parameter code 44201 42602 88101 88501

Basic monitoring objective NAAQS NAAQS NAAQS Public Information

Site type Highest 

concentration

Highest 

concentration

Highest 

concentration

Highest 

concentration

Monitor type SLAMS, PAMS PAMS SLAMS SLAMS

Instrument manufacturer and 

model API Model 400 API Model 200

Thermo Fischer 

Scientific 2025 

Seq.

Met One BAM 

1020

Method code 087 082 118 170

Primary monitor Yes Yes Yes No

FRM/FEM/ARM/other FRM FRM FRM NA

Collecting agency VCAPCD VCAPCD VCAPCD VCAPCD

Analytical lab NA NA NA NA

Reporting agency VCAPCD VCAPCD VCAPCD VCAPCD

Spatial scale Urban Urban Neighborhood Neighborhood

Monitoring start date 06/01/1985 06/01/1985 01/01/1999 01/01/2004

Current sampling frequency Continuous Continuous 1-in-3 days Continuous

Calculated sampling frequency NA NA NA NA

Sampling season Year-round Year-round Year-round Year-round

Probe height 3.5 meters 3.5 meters 6.8 meters 4.6 meters

Distance from supporting structure 1.0 meters 1.0 meters 2.3 meters 2.3 meters

Distance from obstructions on roof None None None None

Distance from obstructions not on 

roof None None None None

Distance from trees 49 meters 49 meters 60 meters 49 meters

Distance to furnace or incinerator 

flue NA NA NA NA

Distance between collocated 

monitors NA NA NA NA

Unrestricted airflow 360 degrees 360 degrees 360 degrees 360 degrees
AMBIENT AIR MONITORING NETWORK PLAN 2013

B-10 VENTURA COUNTY APCD MONITORING DIVISION

Table 12 – Simi Valley Station Information (cont’d)

Pollutant, POC > Ozone, 1 NO2, 1 PM2.5 FRM, 1

PM2.5 

Non-FEM, 3

Probe material for reactive gases Borosilicate glass 

& FEP Teflon

Borosilicate glass 

& FEP Teflon NA NA

Residence time for reactive gases 10.2 seconds 9.3 seconds NA NA

Will there be changes within the 

next 18 months? No No Yes,Reduction

Yes, 

become FEM

Is it suitable for comparison against 

the annual PM2.5 NAAQS? NA NA Yes No, will be with FEM

Frequency of flow rate verification 

for manual PM samplers NA NA 1x/month flow 2x/month leak NA

Frequency of flow rate verification 

for automated PM analyzers NA NA NA

1x/month 

flow and leak 

check

Frequency of one-point QC check 

for gaseous instruments Weekly Weekly NA NA

Last Annual Performance 

Evaluation for gaseous parameters 05/09/2013 05/09/2013 NA NA

Last two semi-annual flow rate 

audits for PM monitors NA NA 11/06/201205/09/2013

11/06/2012

05/09/2013
AMBIENT AIR MONITORING NETWORK PLAN 2013

B-11 VENTURA COUNTY APCD MONITORING DIVISION

Table 12 – Simi Valley Station Information (cont’d)

Local Site Name > Simi Valley – Cochran Street

AQS ID 061112002

GPS coordinates 34.27640, -118.68375

Street address 5400 Cochran St., Simi Valley CA 93063

County Ventura County

Distance to roadways 278 meters

Traffic count 10,200 vehicles/day, 2013

Groundcover Asphalt

Representative statistical 

area name

Oxnard-Thousand Oaks-Ventura 

Metro Area

Pollutant, POC > PM2.5 Speciation, 

1

PM2.5 Speciation, 

1 VOCs, 1 PM10 FEM, 3

Parameter code NA NA NA 81102-3

Basic monitoring objective Research Research Research NAAQS

Site type Other Other

Maximum 

Precursor 

Emissions Impact

Highest 

Concentration

Monitor type STN STN PAMS SLAMS

Instrument manufacturer and 

model Met One Sass URG 3000 N Varian 3800 Met One BAM 1020

Method code 811 871 123 122

Primary monitor Yes Yes Yes No

FRM/FEM/ARM/other Other Other Other FEM

Collecting agency VCAPCD VCAPCD VCAPCD VCAPCD

Analytical lab US EPA US EPA VCAPCD NA

Reporting agency VCAPCD VCAPCD VCAPCD VCAPCD

Spatial scale NA NA Urban Neighborhood

Monitoring start date 12/01/2001 03/01/2009 06/01/1994 06/19/2012

Current sampling frequency 1-in-3 days 1-in-3 days

1-in-3 days and 

days in which 

ozone is predicted 

to exceed .075 

ppm

Continuous

Calculated sampling frequency NA NA NA NA

Sampling season Year-round Year-round July 1 through 

September 30 Year-round

Probe height 6.3 meters 6.0 meters 5.0 meters 4.5 meters

Distance from supporting structure 1.8 meters 1.5 meters 1.5 meters 2.2 meters

Distance from obstructions on roof None None None None

Distance from obstructions not on 

roof None None None None

Distance from trees 73 meters 62 meters 47 meters 48 meters
AMBIENT AIR MONITORING NETWORK PLAN 2013

B-12 VENTURA COUNTY APCD MONITORING DIVISION

Table 12 – Simi Valley Station Information (cont’d)

Pollutant, POC >

PM2.5 Speciation, 

1

PM2.5 Speciation, 

1 VOCs, 1 PM10 FEM, 3

Distance to furnace or incinerator 

flue NA NA NA NA

Distance between collocated 

monitors NA NA NA NA

Unrestricted airflow 360 degrees 360 degrees 360 degrees 360 degrees

Probe material for reactive gases NA NA Borosilicate glass 

& FEP Teflon NA

Residence time for reactive gases NA NA NA NA

Will there be changes within the 

next 18 months? No No No No

Is it suitable for comparison against 

the annual PM2.5 NAAQS? No No NA NA

Frequency of flow rate verification 

for manual PM samplers NA NA NA NA

Frequency of flow rate verification 

for automated PM analyzers NA NA NA

2x/month 

flow and leak 

check

Frequency of one-point QC check 

for gaseous instruments NA NA 2x/smog seasonJune & October NA

Last Annual Performance 

Evaluation for gaseous parameters NA NA 2011 NA

Last two semi-annual flow rate 

audits for PM monitors NA NA NA 11/06/201205/09/2013
AMBIENT AIR MONITORING NETWORK PLAN 2013

B-13 VENTURA COUNTY APCD MONITORING DIVISION

Table 12 – Simi Valley Station Information (cont’d)

Local Site Name > Simi Valley – Cochran Street

AQS ID 061112002

GPS coordinates 34.27640, -118.68375

Street address 5400 Cochran St., Simi Valley CA 93063

County Ventura County

Distance to roadways 278 meters

Traffic count 10,200 vehicles/day, 2013

Groundcover Asphalt

Representative statistical 

area name

Oxnard-Thousand Oaks-Ventura 

Metro Area

Pollutant, POC >

PM10 FRM 

(Primary), 1

PM10 FRM 

(Collo), 2 TNMOC, 3

Parameter code 81102 81102 43102

Basic monitoring objective NAAQS NAAQS Research

Site type Highest Concentration Highest Concentration Maximum Precursor 

Emissions Impact

Monitor type SLAMS SLAMS SLAMS/PAMS

Instrument manufacturer and 

model GMW 1200 GMW 1200 Thermo Electron 55i

Method code 063 063 164

Primary monitor Yes No Yes

FRM/FEM/ARM/other FRM FRM Other

Collecting agency VCAPCD VCAPCD VCAPCD

Analytical lab NA NA NA

Reporting agency VCAPCD VCAPCD VCAPCD

Spatial scale Neighborhood Neighborhood Urban

Monitoring start date 11/04/1986 08/20/1988 03/01/1992

Current sampling frequency 1-in-6 days 1-in-6 days Continuous

Calculated sampling frequency NA NA NA

Sampling season Year-round Year-round Year-round

Probe height 6.3 meters 6.3 meters 3.5 meters

Distance from supporting 

structure 1.8 meters 1.8 meters 1.0 meters

Distance from obstructions on 

roof None None None

Distance from obstructions not 

on roof None None None

Distance from trees 66 meters 65 meters 48 meters

Distance to furnace or 

incinerator flue NA NA NA

Distance between collocated 

monitors 3.0 meters 3.0 meters NA
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Table 12 – Simi Valley Station Information (cont’d)

Pollutant, POC >

PM10 FRM 

(Primary), 1

PM10 FRM 

(Collo), 2 TNMOC, 3

Unrestricted airflow 360 degrees 360 degrees 360 degrees

Probe material for reactive 

gases

NA NA Borosilicate glass & 

FEP Teflon

Residence time for reactive 

gases

NA NA 8.4 seconds

Will there be changes within 

the next 18 months?

Yes,

Reduction

Yes,

Reduction

Maybe

see Section 3.2.5 and 

Appendix F

Is it suitable for comparison 

against the annual PM2.5

NAAQS?

NA NA NA

Frequency of flow rate 

verification for manual PM 

samplers

1x/month

flow

1x/month

flow NA

Frequency of flow rate 

verification for automated PM 

analyzers

NA NA NA

Frequency of one-point QC 

check for gaseous instruments NA NA Weekly

Last Annual Performance 

Evaluation for gaseous 

parameters

NA NA 06/06/2006

Last two semi-annual flow rate 

audits for PM monitors

11/06/2012

05/09/2013

11/06/2012

05/09/2013 NA
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Table 13 – Thousand Oaks Station Information

Local Site Name > Thousand Oaks – Moorpark Road

AQS ID 061110007

GPS coordinates 34.21014, -118.87050

Street address 2323 Moorpark Rd., Thousand Oaks CA 91360

County Ventura County

Distance to roadways 193 meters

Traffic count 17,700 vehicles/day, 2011

Groundcover Asphalt

Representative statistical 

area name

Oxnard-Thousand Oaks-Ventura 

Metro Area

Pollutant, POC > Ozone, 1 PM2.5 FEM, 3 PM2.5 FRM, 1

Parameter code 44201 88101 88101

Basic monitoring objective NAAQS NAAQS NAAQS

Site type Population Exposure Population Exposure Population Exposure

Monitor type SLAMS SLAMS SLAMS

Instrument manufacturer and 

model API Model 400 Met One BAM 1020 Thermo Fischer Scientific 2025 Seq.

Method code 087 170 118

Primary monitor Yes No Yes

FRM/FEM/ARM/other FRM FEM FRM

Collecting agency VCAPCD VCAPCD VCAPCD

Analytical lab NA NA NA

Reporting agency VCAPCD VCAPCD VCAPCD

Spatial scale Urban Neighborhood Neighborhood

Monitoring start date 03/01/1992 01/07/2012 01/01/1999

Current sampling frequency Continuous Continuous 1-in-6 days

Calculated sampling frequency NA NA NA

Sampling season Year-round Year-round Year-round

Probe height 3.7 meters 4.6 meters 4.6 meters

Distance from supporting 

structure 1.1 meters 2.0 meters 2.0 meters

Distance from obstructions on 

roof None None None

Distance from obstructions not on 

roof None None None

Distance from trees 87 meters 87 meters 86 meters

Distance to furnace or incinerator 

flue NA NA NA

Distance between collocated 

monitors NA NA - Colo not approved by EPA yet NA

Unrestricted airflow 360 degrees 360 degrees 360 degrees
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Table 13 – Thousand Oaks Station Information (cont’d)

Pollutant, POC > Ozone, 1 PM2.5FEM, 3 PM2.5 FRM, 1

Probe material for reactive gases Borosilicate glass & 

FEP Teflon NA NA

Residence time for reactive gases 13.1 seconds NA NA

Will there be changes within the 

next 18 months? No No Yes,Reduction

Is it suitable for comparison 

against the annual PM2.5

NAAQS?

NA Yes Yes

Frequency of flow rate verification 

for manual PM samplers NA NA 1x/month flow2x/month leak

Frequency of flow rate verification 

for automated PM analyzers NA 2x/month flow and leak check NA

Frequency of one-point QC check 

for gaseous instruments Weekly NA NA

Last Annual Performance 

Evaluation for gaseous 

parameters

05/01/2013 NA NA

Last two semi-annual flow rate 

audits for PM monitors NA 11/06/201205/01/2013

11/06/2012

05/01/2013
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Table 14 – Simi Valley – Upper Air Station Information

Local Site Name > Simi Valley – Upper Air

AQS ID 061110008

GPS Coordinates 34.29124, -118.79761

Street Address 2801 Madera Rd., Simi Valley CA 93063

County Ventura County

Distance to roadways 443 meters

Traffic count 94,000 vehicles/day, 2011

Groundcover Gravel

Representative statistical 

area name

Oxnard-Thousand Oaks-Ventura 

Metro Area

Last Annual Performance 

Evaluation 05/01/2013

In addition to measuring ambient levels of gaseous and particulate (solid and liquid aerosol) 

air pollutants listed in Tables 9 – 14 above, stations in Ventura County also collect 

meteorological data. Table 15 lists the types of meteorological data collected by site, and 

whether the data is being collected as part of SLAMS or SLAMS and PAMS networks.

Table 15 – Meteorological Data Collected at Sites

Local Site Name

AQS ID

Wind SpeedWind Direc5tionTemperatureRelative HumidityTotal Solar RadiationRainfallUltraviolet RadiationBarometric PressureVisibility

El Rio – Rio Mesa School #2

061113001

     

Ojai – Ojai Avenue

061111004

     

Piru – Pacific Avenue

061110009

     

Simi Valley – Cochran St

061112002

     

Simi Valley Upper Air Profiler

061110008

        

Thousand Oaks – Moorpark Rd

061110007

     

 Monitored as part of SLAMS network.

 Monitored as part of SLAMS and PAMS networks.
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Appendix C Minimum Monitoring Requirements

40 CFR 58.10, Appendix D specifies the minimum requirements for air monitoring networks. As shown in Tables 16 through 25, 

the VCAPCD air monitoring network meets or exceeds the minimum monitoring requirements for all criteria pollutants.

Certain monitoring requirements in 40 CFR 58 are based upon Metropolitan Statistical Areas (MSAs). MSAs are part of a 

population, economic and social-based classification of geographical regions developed by the U.S. Census Bureau. An MSA may 

include one or more counties. However, not all counties are within an MSA. The VCAPCD contains a single MSA, the OxnardThousand Oaks-Ventura MSA. A Core Based Statistical Area (CBSA) is a collective term for MSAs and micropolitan areas, so 

since there is only one MSA in Ventura County, the MSA and CBSA are the same.

Ozone

Table 16 – Minimum Monitoring Requirements for Ozone

MSA County

Population 

(Census Year)

8-Hour 

Design Value 

(Years)

Design Value 

Site

(AQS ID)

# 

Required 

Monitors

# 

Active Monitors

# Add’l

Monitors 

Needed

Oxnard-Thousand OaksVentura Ventura

County

823,318

(2010)

81 ppb

(2010-2012)

Simi Valley

(061112002) 2 5 0

Monitors required for SIP or Maintenance Plan: 2
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PM2.5

With regard to 40 CFR 58.10(c), “...review of changes to a PM2.5 monitoring network that impact the location of a violating PM2.5

monitor.” Should such a violation occur, VCAPCD would review the possible causes for the violation (weather, geography, 

changes to the local area). Prior to making any changes to the PM2.5 monitoring network to address such a violation, VCAPCD 

would consult EPA and CARB regarding possible methodologies to better monitor PM2.5 and better define the issue. Any changes 

to the monitoring network related to a violating monitor that would change PM2.5 monitoring would be through a process of public 

comment on the plan via the public notification process.

Table 17 – Minimum Monitoring Requirements for PM2.5 SLAMS

MSA County

Population 

(Census 

Year)

Annual

Design

Value 

(Years)

Annual 

Design Value

Site

(AQS ID)

Daily Design 

Value 

(Years)

Daily Design 

Value Site

(AQS ID)

# 

Required

SLAMS 

Monitors

# 

Active 

SLAMS 

Monitors

# Add’l 

SLAMS 

Monitors 

Needed

Oxnard-Thousand Oaks-Ventura Ventura 

County

823,318

(2010)

8.9 μg/m3

(2010-2012)

Thousand 

Oaks

(061110007)

Simi Valley

(061112002)

20 μg/m3

(2010-2012)

Thousand 

Oaks

(061110007)

1 8 0

Table 18 – Minimum Monitoring Requirements for Continuous PM2.5 Monitors

MSA County

Population 

(Census 

Year)

Annual

Design

Value 

(Years)

Annual 

Design Value

Site

(AQS ID)

Daily Design 

Value 

(Years)

Daily Design 

Value Site

(AQS ID)

# 

Required 

Continuous

Monitors

# Active 

Continuous 

Monitors

# Add’l 

Continuous 

Monitors 

Needed

Oxnard-Thousand Oaks-Ventura Ventura 

County

823,318

(2010)

8.9 μg/m3

(2010-2012)

Thousand 

Oaks

(061110007)

Simi Valley

(061112002)

20 μg/m3

(2010-2012)

Thousand 

Oaks

(061110007)

1 5 0

Monitors required for SIP or Maintenance Plan: None.
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PM10

PM10-2.5 monitoring is required only at NCore stations. There is no requirement for an NCore station in Ventura County. 

Table 19 – Minimum Monitoring Requirements for PM10

MSA County

Population 

(Census Year)

Max 

Concentration

Max 

Concentration 

Site

# 

Required 

Monitors

# 

Active 

Monitors

# Add’l

Monitors 

Needed

Oxnard-Thousand Oaks-Ventura Ventura 

County

823,318

(2010) 39 μg/m3 Simi Valley(061112002)

1 - 2 5 0

Monitors required for SIP or Maintenance Plan: None.

Table 20 – Minimum Monitoring Requirements for PM10-2.5

MSA County

Population 

(Census Year)

Max 

Concentration

Max 

Concentration 

Site

# 

Required 

Monitors

# 

Active 

Monitors

# Add’l

Monitors 

Needed

Oxnard-Thousand Oaks-Ventura Ventura 

County

823,318

(2010) 39 μg/m3 Simi Valley(061112002)

0 0 0

Monitors required for SIP or Maintenance Plan: None.

NO2

The VCAPCD previously operated monitors to measure levels of nitrogen dioxide (NO2) at the Ojai, Ventura, and Thousand Oaks 

monitoring stations. Because of the low levels recorded, NO2 monitoring at these stations was discontinued in July 2004. The 

VCAPCD currently monitors for NO2 at El Rio and Simi Valley monitoring stations as part of PAMS. There are no NO2 monitors 

required in Ventura County for RA-40 monitoring. There are no NO2 monitors required for SIP or maintenance planning. 

In 2010, EPA adopted a new NAAQS for nitrogen dioxide (NO2). Per 40 CFR 58.10(a)(5)(v), one Near-Road monitor NO2 monitor 

will be required for Ventura County. When NO2 Near-Road requirements are defined by EPA, VCAPCD expects to establish the

ambient NO2 Near-Road monitoring site along US Highway 101 (the Ventura Freeway), in Thousand Oaks between Hampshire 
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Road and Westlake Village Road. The Near-Road NO2 monitor must be operational by January 1, 2017. Discussion of the future 

Near-Road NO2 monitoring site is included in Section 3.2.4. 

Table 21 – Minimum Monitoring Requirements for NO2

CBSA

Population 

(Census 

Year)

Max AADT 

Counts 

(Year)

# 

Required 

Near-Road

Monitors

# 

Active 

Near-Road

Monitors

# 

Add’l

Near-Road

Monitors 

Needed

# 

Required 

Area-wide 

Monitors

# Active 

Area-wide 

Monitors

# Add’l 

Area-wide 

Monitors 

Needed

Oxnard-Thousand OaksVentura823,318

(2010)

189,000

(2011) 0 0 0 0* 2 0

* Review of minimum monitoring requirements indicates that there is no requirement for area-wide NO2 monitoring in Ventura County. Corrections were 

made in AQS to change monitor type to PAMS in June 2013 for the El Rio and Simi Valley NO2 monitors.

Monitors required for SIP or Maintenance Plan: None

Monitors required for PAMS: 2

EPA Regional Administrator-required monitors per 40 CFR 58, App. D 4.3.4: None.

Sulfur Dioxide (SO2)

The VCAPCD previously operated a monitor to measure SO2 at the El Rio monitoring station. Because of the low levels recorded, 

SO2 monitoring was discontinued in July 2004. 

On June 2, 2010, EPA established a new 1-hour SO2 NAAQS, effective August 23, 2010, which is based on the same 3-year 

average of the annual 99th percentile of 1-hour daily maximum averages in ppb (level: 75). MSA’s with a population-weighted 

emission index (PWEI) greater than a threshold would be required to establish an ambient SO2 monitoring program by 

January 1, 2013. On May 27, 2011, EPA Region 9 issued an email from Meredith Kurpius, PhD, Air Division, stating that “EPA did 

not expect Ventura County to have any additional SO2 monitoring requirements based on the 2008 NEI." Therefore, based on the 

2008 National Emissions Inventory (NEI), Ventura County fell below the PWEI threshold, releasing the VCAPCD from the need to 

monitor SO2. There are no NO2 monitors required for SIP or maintenance planning.
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Table 22 – Minimum Monitoring Requirements for SO2

CBSA County

Population 

(Census Year) Total SO2

Population Weighted 

Emissions Index 

# 

Required 

Monitors

# 

Active 

Monitors

# Add’l

Monitors 

Needed

Oxnard-Thousand OaksVenturaVentura

County

823,318

(2010) NA NA 0 0 0

Monitors required for SIP or Maintenance Plan: None.

EPA Regional Administrator-required monitors per 40 CFR 58, App. D 4.4.3: None.

CO

The VCAPCD previously operated monitors to measure levels of CO at the El Rio and Simi Valley monitoring stations. Because of 

the low levels recorded, CO monitoring at these stations was discontinued in March and July 2004. 

40 CFR 58, Appendix D, Section 4.2.1 states that CBSAs having a population of 1,000,000 or more persons are required to have 

one CO monitor collocated with a Near-Road NO2 monitor, as required by 40 CFR 58, Appendix D, Section 4.3.2. Because the 

population of the Oxnard-Thousand Oaks-Ventura CBSA is less than 1,000,000 persons, there is no requirement for a Near-Road

CO monitor in Ventura County.

Table 23 – Minimum Monitoring Requirements for CO

CBSA County

Population 

(Census Year)

# Required 

Near-Road Monitors

# Active 

Near-Road Monitors

# Add’l

Monitors Needed

Oxnard-Thousand OaksVenturaVentura

County

823,318

(2010) 0 0 0

Monitors required for SIP or Maintenance Plan: None.

EPA Regional Administrator-required monitors per 40 CFR 58, App. D 4.2.2: None.
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NCore

The NCore Network, formerly known as the national Air Monitoring Statons (NAMS) is a multi-pollutant air monitoring network 

across the United States that integrates several advanced measurement systems for particles, pollutant gases and meteorology. 

Most NCore stations have been operating since the formal start of the network on January 1, 2011. NCore sites are required 

under 40 CFR Part 58.10(a)(3), and are generally sited in large metropolitan areas at a rate of one site per state. There is no 

requirement for an NCore site in Ventura County.

Lead (Pb)

In 2008, EPA revised the NAAQS for lead from 1.5 μg/m3to 0.15 μg/m3. The regulation requires that state and local agencies 

establish an ambient lead monitor by January 1, 2011. In December 2009, EPA proposed revisions to the regulation that revise 

“source oriented” monitoring requirements. As a result of EPA’s revisions, and EPA’s recent acceptance of the VCAPCD’s lead 

emission inventory for airports, the VCAPCD will not be subject to the lead monitoring requirements.

Table 24 – Minimum Monitoring Requirements for Pb at NCore

NCore Site CBSA Population 

(Census Year)

# 

Required Monitors

# 

Active Monitors

# Add’l

Monitors Needed

NA Oxnard-Thousand 

Oaks-Ventura

823,318

(2010) 0 0 0

Table 25 – Source Oriented Lead Monitoring (Including Airports)

Source Name Address

Pb Emissions

(tons per 

year)

Emission 

Inventory 

Source

Max 3-Month 

Design Value

Design Value 

Date

# 

Required 

Monitors

# 

Active 

Monitors

# Add’l

Monitors 

Needed

NA NA NA NA NA NA 0 0 0

Monitors required for SIP or Maintenance Plan: None.

EPA Regional Administrator-required monitors per 40 CFR 58, App. D 4.5(c): None.
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Appendix D Ambient Air Quality Standards

Table 26 – Ambient Air Quality Standards

Pollutant Averaging Time California Standards National Standards

Ozone (O3) 

8 Hour 0.070 ppm 0.075 ppm

1 Hour 0.09 ppm —

Respirable Particulate 

Matter (PM10) 

24 Hour 50 μg/m3150 μg/m3

Annual Arithmetic Mean 20 μg/m3

Fine Particulate 

Matter (PM2.5) 

24 Hour — 35 μg/m3

Annual Arithmetic Mean 12 μg/m315 μg/m3

Carbon Monoxide 

(CO)

8 Hour 9.0 ppm 9 ppm

1 Hour 20 ppm 35 ppm

Nitrogen Dioxide

(NO2)

1 Hour 0.18 ppm 100 ppb

Annual Arithmetic Mean 0.030 ppm 0.053 ppm

Sulfur Dioxide

(SO2)

1 Hour 0.25 ppm 75 ppb 

3 Hour — 0.5 ppm (secondary)

24 Hour 0.04 ppm 0.14 ppm (primary, 

certain areas)

Annual Arithmetic Mean —

0.030 ppm (primary, 

certain areas)

Lead

30 Day Average 1.5 μg/m3 —

Calendar Quarter —

1.5 μg/m3

(certain areas)

Rolling 3-Month Average — 0.15 μg/m3

Visibility Reducing 

Particles 8 Hour

Sufficient amount to 

reduce the prevailing 

visibility to less than ten 

miles when the relative 

humidity is less than 70%

—

Sulfates 24 Hour 25 μg/m3 —

Hydrogen Sulfide 

(H2S) 1 Hour 0.03 ppm —

Vinyl Chloride 24 hour 0.01 ppm —

As of June 7, 2012.
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Appendix E Collocation Requirements

40 CFR 58, Appendix A, Section 3 includes collocation requirements for PM2.5, continuous 

PM2.5, PM10, and Pb monitoring networks. The requirements apply at the PQAO level. A 

PQAO is a monitoring organization or a coordinated aggregation of such organizations that 

is responsible for a set of stations that monitors the same pollutant and for which data quality 

assessments can logically be pooled. Ventura County is in the CARB PQAO.

PM2.5 FRM

There are three Thermo Fischer Scientific 2025 Sequential PM2.5 FRM samplers (method 

code 118) in Ventura County. They are all designated as primary monitors, and are located 

at the El Rio, Simi Valley, and Thousand Oaks stations. There are no collocated PM2.5 FRM 

samplers in the county. However, collocation requirements apply at the PQAO level. The 

CARB 2012 Annual Monitoring Report for Small Districts in California indicates that the 

CARB PQAO, which is the PQAO for Ventura County, is meeting its collocation 

requirements for method code 118.

Method Code # Primary Monitors

# Required Collocated 

Monitors

# Active Collocated 

Monitors

118 3 0 0

Continuous PM2.5

There are four Met One BAM 1020 continuous PM2.5 FEM samplers (method code 170) in 

Ventura County, at the El Rio, Ojai, Piru, and Thousand Oaks stations. Two of these 

samplers are designated as primary monitors, at the Ojai and Piru stations. There is also 

one Met One BAM 1020 continuous PM2.5 non-FEM sampler (method code 731) at the Simi 

Valley station. There are no collocated PM2.5 FRM samplers in the county. However, 

collocation requirements apply at the PQAO level. The CARB 2012 Annual Monitoring 

Report for Small Districts in California indicates that the CARB PQAO, which is the PQAO 

for Ventura County, is meeting its collocation requirements for method code 170.

As stated above, collocation requirements apply at the PQAO level. Prior to making any 

changes to our PM2.5 network, we will consult with CARB (our PQAO) and EPA Region 9. 

Following our 2013 FRM to FEM comparison study described in Section 3.1.2, Recent

Changes to the PM2.5 and PM10 Monitoring Networks, should the study show good 

agreement, then VCAPCD would request that we opt out of any colocation requirements 

under the PQAO.
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Method Code # Primary Monitors

# Required Collocated 

Monitors

# Active Collocated 

Monitors

170 (FEM) 2 1 0

PM10

There are three GMW 1200 PM10 FRM samplers (method code 063) in Ventura County. 

Two of these samplers are designated as primary monitors, one at the El Rio station and 

one at the Simi Valley station. There is one collocated PM10 FRM sampler at the Simi Valley 

monitoring station, located 3 meters from the primary PM10 FRM sampler. If collocation 

requirements applied at the air district level, Ventura County would be meeting its collocation 

requirements. However, collocation requirements apply at the PQAO level. The CARB 

2012 Annual Monitoring Report for Small Districts in California indicates that the CARB 

PQAO, which is the PQAO for Ventura County, needs additional collocated monitors for 

method code 063, which it intended to address in the year following distribution of the report.

Method Code # Primary Monitors

# Required Collocated 

Monitors

# Active Collocated 

Monitors

063 2 1 1

Non-NCore Pb

There is no source or non-source Pb monitoring required in Ventura County, and there are 

no NCore sites in Ventura County. Therefore, there are no collocated monitors in Ventura 

County.

Method Code # Primary Monitors

# Required Collocated 

Monitors

# Active Collocated 

Monitors

NA 0 0 0
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Appendix F Air Monitoring Network Related Correspondence

This appendix contains correspondence about matters related to the ambient air monitoring 

network in Ventura County. Table 27 summarizes the documentation in this appendix.

Table 27 – VCAPCD Air Monitoring Network Correspondence

Date Author Recipient Subject

11/22/2011

Kent Field, 

VCAPCD

Matt Lakin, EPA, 

Region 9

Request for Approval of 

Modifications to Particulate Monitoring Networks

02/10/2012

Matthew Lakin, 

EPA, Region 9

Kent Field,

VCAPCD

Response to Request for Approval of 

Modifications to Particulate Monitoring Networks

05/01/2013

Michael Villegas,

VCAPCD

Fletcher Clover,

EPA, Region IX 2012 Annual Air Monitoring Data Certification

05/08/2013

Kent Field,

VCAPCD

Meredith Kurpius

EPA, Region 9

Email exchange about discontinuation of the continuous 

hydrocarbon sampling at the Simi Valley station 

06/20/2013

Kent Field,

VCAPCD

Matthew Lakin

EPA, Region 9

Formal letter discontinuation of the continuous 

hydrocarbon sampling at the Simi Valley station
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F-3 VENTURA COUNTY APCD MONITORING DIVISION
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F-4 VENTURA COUNTY APCD MONITORING DIVISION
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F-5 VENTURA COUNTY APCD MONITORING DIVISION
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F-6 VENTURA COUNTY APCD MONITORING DIVISION
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F-7 VENTURA COUNTY APCD MONITORING DIVISION
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F-8 VENTURA COUNTY APCD MONITORING DIVISION
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F-9 VENTURA COUNTY APCD MONITORING DIVISION
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F-10 VENTURA COUNTY APCD MONITORING DIVISION
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F-11 VENTURA COUNTY APCD MONITORING DIVISION
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F-12 VENTURA COUNTY APCD MONITORING DIVISION
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F-13 VENTURA COUNTY APCD MONITORING DIVISION