An Overview of EPA’s Quality Assurance Guidance for Ambient Air Quality Monitoring Data Data Analysis and Interpretation February 12 – 14, 2008, Tempe, AZ Catherine Brown, EPA Region 9

What are the QA elements for ambient monitoring data?  Monitoring Objectives  PQAO defined  Network Design  DQO process  EPA’s MQO’s for ambient monitoring (some new)  Data Quality Assessments  Tools

EPA’s Ambient Air Quality Monitoring Program Objectives  Provide air pollution data to general public in a timely manner  Support compliance with air quality standards & emissions strategy development  Support air pollution research studies

Primary Quality Assurance Organizations To aggregate monitoring data and assess DQO’s, should have common –SOPs, QAPPs –Team of operators with common training –Calibration facilities and standards –QA oversight –Management, lab or HQ

Design of Ambient Monitoring Networks  Highest concentration areas  Population exposure  Source-oriented sampling  General background  Pollutant transport  Visibility and welfare effects * * Note: Appendix A requirements now apply to PSD monitoring

EPA’s Quality System  Now fully based on DQO process (December 2006)  Decision makers must understand probability of incorrect NAAQS decision (data uncertainty)  Data Quality Assessments determine DQOs are achieved

Measurement Quality Objectives  Table A-2 in 40 CFR 58 Appendix A  Note: Some statistics are new –Defines measurement quality samples required for manual and automated methods for each criteria pollutant

Data Quality Assessments Evaluate each monitoring program or project for these indicators  Representativeness  Precision  Bias  Detectability  Completeness  Comparability

Summary  QA requirements apply to environmental measurements used in decision-making  Data quality assessments help organize and understand complex datasets  Statistical tools available from EPA

EPA References  Guidance on Systematic Planning Using the Data Quality Objectives Process EPA/240/B-06/001 Feb  Guideline on the Meaning and Use of Precision and Bias Data Required by 40 CFR Part 58 Appendix A – Version 1.1

EPA References (cont.)  EPA Quality Assurance Handbook  Data Assessment Statistical Calculator (DASC) Software for calculating new precision and bias statistics

EPA References (cont.)  2006 Criteria Pollutant Quality Indicator Summary Report for AQS Data