Quality Assurance

Updated March 6, 2015

The Air Resources Board (ARB) is the governmental agency delegated the authority and responsibility for collecting ambient air quality data as directed by the Clean Air Act. The U.S. Environmental Protection Agency (U.S. EPA) designated ARB as one of the four Primary Quality Assurance Organizations (PQAO) responsible for air monitoring in California. The Quality Management Plan (QMP) describes the quality management system used by ARB and participating local air monitoring organizations that comprise ARB's PQAO. Click on the tabs below for more quality assurance information and references associated with ambient air monitoring.

Quality Management Branch

ARB's Quality Management Branch (QMB) is primarily responsible for providing quality assurance oversight of air monitoring activities within its PQAO.

Quality Management Branch Organization

Schematic of QMB organization
ARB's QMB is one of six branches in the Monitoring and Laboratory Division (MLD). QMB is directly responsible for the precision and accuracy of all data generated and collected by MLD, and indirectly responsible for precision and accuracy of all data collected by local and private air monitoring agencies in California's air monitoring network. QMB performs a complex array of quality assurance and quality control activities to ensure that ambient air data are in compliance with all applicable state and federal quality assurance requirements. See the QMP for more information about the organizational structure of MLD and QMB.

MLD works with the Air Quality Planning and Science Division (AQPSD) which has primary responsibility for network planning and assessment. AQPSD works with local air districts and MLD to implement monitoring requirements for new and updated standards and shares responsibility with MLD for upload and certification of ambient air data.

The Ambient Air Quality Monitoring Network page has links and descriptions of ARB's various air monitoring programs and services.

Primary Quality Assurance Organization

ARB is required by federal regulations to provide quality assurance oversight to local air monitoring organizations within ARB's PQAO to ensure that consistent procedures are followed to produce data of similar quality.

What is a PQAO?

Common factors diagram

A PQAO is a monitoring organization or a coordinated aggregation of such organizations that is responsible for a set of air monitoring stations that monitor the same pollutants and for which data precision and accuracy assessments can logically be pooled. Each criteria pollutant sampler/monitor at a monitoring station in the State and Local Air Monitoring Station Network must be associated with a single PQAO.  Measurement precision and accuracy among all air monitoring stations in a PQAO is expected to be reasonably homogeneous based on five common operation, oversight and support factors.

To address the five common factors and ensure compliance with State and Federal air monitoring requirements, ARB collaborates with each monitoring organization in its PQAO to define respective Roles and Responsibilities with regard to the operation of the State's ambient air monitoring network.

ARB PQAO Contacts

Michael Miguel, Chief, Quality Management Branch (916) 322-0960.

Patrick Rainey, Manager, Quality Management Section (916) 327-4756.

The Updated icon ARB PQAO Contact List contains the primary contact designated by each monitoring organization and who is responsible for sharing information within the respective organization.

District Liaisons:

Carissa Ganapathy
(916) 322-7105
  • Eastern Kern
  • Great Basin
  • Lake
  • Northern Sonoma
  • Sacramento
Greg Gilani
(916) 445-9391
  • Monterey
  • Northern Sierra
  • Placer
  • Santa Barbara
  • San Luis Obispo
Darsi Goto
(916) 324-9656
  • Imperial
  • Mojave/Antelope
  • Shasta
  • Siskiyou
  • Tehama
Maria Salomon
(916) 322-3267
  • Mendocino
  • North Coast
  • San Joaquin
  • Ventura
  • Yolo/Solano

Monitoring Organizations in ARB's PQAO

ARB's PQAO consists of ARB and 32 local air monitoring organizations throughout California. Monitoring organizations in ARB's PQAO are expected to follow, to the extent practical, the five common factors listed above. The 21 monitoring organizations listed below operate ambient air monitoring networks in ARB's PQAO.

Antelope Valley Eastern Kern Great Basin Imperial Lake
Mendocino Mojave Desert Monterey Bay North Coast Northern Sierra
Northern Sonoma Placer Sacramento San Joaquin San Luis Obispo
Santa Barbara Shasta Siskiyou Tehama Ventura

Other PQAOs in California

State of California map showing other PQAOs.
Link to Bay Area AQMD South Coast AQMD San Diego County Air Pollution Control District The U.S. EPA designated ARB as the PQAO for all of California with the exception of the following:


Quality Management Documents

NEW icon Quality Assurance Bulletins (Guidance for monitoring organizations in California)

The following Quality Assurance Bulletins provide guidance and clarification for specified quality assurance and quality control procedures:

Updated icon ARB Document Repository (QA documents used by monitoring organizations in California)

All monitoring organizations within ARB's PQAO are required to utilize and follow ARB's quality management documents (QMP, QAPPs, SOPs, etc.) for each primary area of operation or submit alternative documents to ARB and/or U.S. EPA for review and approval. The Updated icon Quality Management Document Repository identifies specific documents utilized by ARB, monitoring organizations within ARB's PQAO, and other participating PQAOs.

ARB Quality Assurance Manual (QMP, QAPPs, SOPs)
Requirements, Guidance, and Review Checklists (QMP, QAPP, and SOPs)

The following ARB checklists and U.S. EPA documents are helpful for developing and reviewing QA documents.

Visit U.S. EPA's Agency-wide Quality System Documents webpage for additional QA document guidance.

Quality Assurance Reports (Precision and Accuracy Results, Data Quality Reports)
EPA Quality Assurance Handbook

The U.S. EPA Quality Assurance Handbook for Air Pollution Measurement Systems is comprised of five volumes. Volumes II and IV focus on ambient air monitoring and associated data collection activities. 

Code of Federal Regulations

Code of Federal Regulations (CFR), Title 40, Parts 50, 53 and 58 - regulations for air monitoring and related quality assurance.

  • Part 50 - National Primary and Secondary Ambient Air Quality Standards
  • Part 53 - Ambient Air Monitoring Reference and Equivalent Methods (FRM and FEM)
  • Part 58 - Ambient Air Quality Surveillance -- Includes QA, operations, siting, network requirements
  • Part 58 indexed - Unofficial version with indexed appendices

Quality Assurance Activities


Performance Audits

Annually, ARB conducts performance audits of gaseous, particulate matter, and meteorological equipment operated at air monitoring sites throughout ARB's PQAO to determine the accuracy of measurements in accordance with all applicable requirements, including 40 CFR, Part 58, Appendix A.

Technical System Audits

A Technical System Audit (TSA) is an on-site inspection and review of an organization's ambient air monitoring program. The audit includes a review of sample collection, sample analysis, data management procedures, facilities, documentation, staff duties, and training to assure compliance with all applicable air monitoring requirements.  ARB is responsible for conducting TSAs of ambient air monitoring organizations within its PQAO on a schedule of every three to five years.  See the link above for additional information related to TSAs. The TSA Questionnaire can be utilized to facilitate the TSA process.

Corrective Action Notification (CAN)

The Corrective Action Notification (CAN) process was developed for ARB's PQAO to document, investigate, correct, and reduce the recurrence of air monitoring issues that may impact or potentially impact data quality, completeness, storage, or reporting.  The objective of the CAN process is to improve the quality of air monitoring data and to ensure compliance with State, federal, and local requirements.  The link above provides additional information related to the CAN process, including the CAN SOP and CAN Form.

Air Quality Data Action

An Air Quality Data Action (AQDA) is a request for an investigation of the validity of ambient air quality data for a certain period of time. AQDAs are generally issued by QMB staff based upon review of field calibrations or audit results that show air monitoring equipment operating outside ARB's control limits or not meeting appropriate siting conditions. AQDAs are issued to the person responsible for data collection and submittal for the monitoring organization. A copy of it is also sent to AQPSD's Air Quality Planning Branch (AQPB), which withholds potentially impacted data from processing and publication until appropriate actions are taken. More information is available in the QMP, Section 9.15.

Services and Resources

Standards Laboratory

As defined in 40 CFR, Part 58, Appendix A, Section 3.1.1, one of the factors considered in defining a PQAO is the utilization of common calibration facilities and standards. The use of common calibration facilities and standards helps ensure the data produced are of similar quality.

Updated icon Training Resources

In Person Training

ARB, U.S. EPA, and local air districts are collaboratively developing PQAO Training Modules for air monitoring staff and management at all levels. The modules are designed to emphasize the fundamentals in key areas of ambient air monitoring. The infographic New icon Data's Journey to AQS and Beyond: The Data Management Process is now posted. Be cautious printing. This version is about 12 feet long.

Online Training

PQAO List Serve

The PQAO Contact List Serve is open to the public. ARB uses the List Serve to share pertinent air monitoring information with the local air monitoring organizations and other interested parties.