Ambient Air Monitoring Quality Assurance
Background
The EPA’s Ambient Air Monitoring Group (AAMG) oversees various QA/QC programs and activities to support air quality measurement. This page provides information on the various aspects of the EPA's ambient air monitoring QA program.
On this page:
- QA Rules and Regulations
- National Quality Assurance Programs
- Quality Assurance Guidance Documents
- Data Certification and Validation
- Quality Indicator Assessment Reports
- Newsletters
- Pollutant/Network Specific QA
- Training
- Other QA Links
Rules and Regulations
The Clean Air Act (CAA) and its amendments provide the framework for the protection of air quality. As part of this framework, EPA establishes and periodically revises National Ambient Air Quality Standards (NAAQS) for the criteria pollutants, and the Agency has established requirements for monitoring networks for these pollutants. The QA requirements for ambient air monitoring are located in Title 40 of the Code of Federal Regulations (40CFR) Parts 50, 53, and 58:
- 40 CFR Part 50 Appendix D – Standard Reference Photometer (SRP) for O3
- 40 CFR Part 58.15 – Annual Air Monitoring Data Certification
- 40 CFR Part 58 Appendix A – Ambient Air Monitoring Quality Assurance Requirements including:
- Protocol Gas Verification Program
- National Performance Evaluation Program NPEP – National Performance Audit Program (NPAP) and Performance Evaluation Program (PEP)
- Technical Systems Audits (TSAs)
- Standards
- Collocation Requirements
- 40 CFR Part 58 Appendix E – Probe and Monitoring Path Siting Criteria
National Quality Assurance Programs
This section provides information on the National Quality Assurance Programs overseeing EPA's Ambient Air Monitoring Program, including the National Performance Evaluation Program (NPEP). A critical element in any quality assurance program is the process of independent assessment. Independent assessment provides for a level of objectivity and consistency in the determination of data quality. As the Federal organization responsible for the implementation and oversight of the Ambient Air Monitoring Program, OAQPS, in partnership with the EPA Regions and the National Environmental Research Laboratory (NERL), have always provided the function of independent assessment that includes: site characterization and network reviews, technical systems audits and performance evaluations. Performance evaluations (PE) are a type of audit in which the quantitative data generated in a measurement system are obtained independently and compared with routinely obtained data to evaluate the proficiency of an analyst or laboratory.
- National Performance Assessment Program for O3, NO2, SO2, and CO
- PM2.5 Performance Evaluation Program
- PM2.5 Gravimetric Round Robin
- Ozone Standard Reference Photometer Program
- Ambient Air Protocol Gas Verification Program
- QC of Filters for PM2.5, PM10 and Low Volume Pb
- Lead Performance Evaluation Program (Pb-PEP)
- Technical Systems Audits
- Ambient Air Monitoring QA Programs (Poster)
Quality Assurance Guidance Documents
The following documents provide guidance for the implementation of the QA rules and regulations. Additional pollutant specific QA guidance documents can also be found on the specific network pages.
- Best Practices for Review and Validation of Ambient Air Monitoring Data (PDF) (96 pp, 5.9MB, August 2021)
- Appendix A - Data Verification and Validation Checklists (xls) (109 K, July 2021)
- T640 Validation Template (284 K, November 2021)
- T640x Validation Template (290 K, November 2021)
- National Performance Audit Program, PM2.5, PM10-2.5, and Lead Performance Evaluation Program Implementation Decision Memorandum for Calendar Year 2025 (PDF) (388K, October 2024)
- Residence Time Determination Worksheet (xls)
- Air Monitoring QAPP Review Checklist (docx) (October 2018)
- Technical Note- Clarifications and Guidance on Residence Time Determination (PDF)(5 pp, 431 K, June 2019)
- Guide to Writing Quality Assurance Project Plans for Ambient Air Monitoring Networks (PDF)(46 pp, 534 K, August 2018)
- QA Handbook for Air Pollution Measurement Systems: "Volume I: A Field Guide to Environmental Quality Assurance (PDF)(54 pp, 1 MB, April 1994)
- QA Handbook for Air Pollution Measurement Systems:"Volume II: Ambient Air Quality Monitoring Program (PDF)(346 pp, 5 MB, January 2017)
- QA Handbook for Air Pollution Measurement Systems:"Volume IV: Meteorological Measurements (PDF) (191 pp, 5.2 MB, March 2008)
- QA Handbook for Air Pollution Measurement Systems: "Volume V: Precipitation Measurement Systems (PDF) (260 pp, 3.1 MB, April 1994)
- Planned Edits for Revision to the 2017 QA Handbook (PDF)(1 pg, 85 K, March 2018)
- QA Handbook Appendix D Validation Templates (PDF)(54 pp, 410 K, March 2017)
- Minor Changes to the January 2017 Version of the Validation Template (PDF)(2 pp, 94 K, March 2017)
Quality Indicator Assessment Reports
On this page:
- Data Assessment Statistical Calculator (xls) - Software to assist in calculating precision and bias statistics
- Guideline on the Meaning and the Use of Precision and Bias Data Required by 40 CFR part 58 Appendix A (pdf)
- Multipoint Verification/Calibration Assessment Worksheet (xlsx) - Software to assist in evaluating calibration data
- 504 QA Data Assessment Tool Version 6-5b (xlsm)
- 2014 Criteria Pollutant Quality Indicator Summary Report
- IML Gravimetric Laboratory TSA 2014
- Frequently Asked Questions About the AMP 255 Report
Newsletters
EPA periodically publishes a newsletter providing National QA program updates and other ambient air monitoring QA related news. Copies of the current and past newsletters can be found at the following link.
Pollutant/Network Specific QA
In addition to the information on this page, pollutant specific QA/QC documents such as program QAPPs, Standard Operating Procedures, and other QA guidance may be found on the specific monitoring network pages.
Data Certification and Validation
The following page contains information and guidance on the data certification process and Q&A on Ambient Air Monitoring Data Certification including data certification flag values.
Training
This section contains links to training materials used to support Quality Assurance activities.