Quality Assurance

Updated October 31, 2017

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. With smartphones view the Station Operator's Page.

What's New!

The 2016 Data Quality Report is now available. This report describes the quality of the ambient air quality data in quantifiable terms in relation to measurement quality objectives established by U.S. Environmental Protection Agency. See the QA Bulletin tab below for the latest information about the reporting requirements for PM10, PM2.5, and Pb flow rate verifications to AQS.

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:

Aman Bains
(916) 323-0032
  • Mendocino
  • North Coast
  • Yolo/Solano
  • Ventura
Jeannine Berry
(916) 322-5449
  • Shasta
  • Siskiyou
  • Tehama

Leah Mathews
(916) 324-9656
  • Imperial
  • Mojave/Antelope
Andrea McStocker
(916) 322-3267
  • Eastern Kern
  • Lake
  • San Joaquin
  • Santa Barbara
Grace Tuazon
(916) 322-7105
  • Great Basin
  • Northern Sonoma
  • Placer

Kyle Vagadori
(916) 445-9391
  • Monterey
  • Northern Sierra
  • Sacramento
  • San Luis Obispo
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 AQMDSouth Coast AQMDSan 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

Quality Assurance Bulletins (Guidance for monitoring organizations in California)
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 Quality Management Document Repository identifies specific documents utilized by ARB, monitoring organizations within ARB's PQAO, and other participating PQAOs.

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.

Quality Assurance Reports (Precision and Accuracy Results [PANDA], 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

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. The link above provides additional information related to the CAN process, including the CAN SOP and CAN Form. District staff can view CANs issued to their District in PANDA.

Air Quality Data Action (AQDA)

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.

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.


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.

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.