EPA Precursor Gas Training Workshop Precursor Gas Quality Assurance Implementation Dennis K. Mikel EPA Office of Air Quality Planning and Standards

EPA Precursor Gas Training Workshop Outline QA System Development QA Requirements for the NCore Program –Changes to the 40 CFR Appendix A – Overview of the New Calculations Data Assessment Statistical Calculator (DASC) Comparing the DQO/MQOs to the Burden’s Creek data National Performance Audit Program

EPA Precursor Gas Training Workshop A structured and documented management system that describes how and by whom an organization assures quality in its work. What is a Quality System ? – Make correct decisions – Optimize resource use Quality System Goals EPA Your Program The Project!

EPA Precursor Gas Training Workshop Reporting Where are we?

EPA Precursor Gas Training Workshop Changes in the QA Regulations (40 CFR Part 58 Appendix A) Ensured regs reflected current EPA QA policies and requirements Combined Appendix A and B (PSD) Institute the Primary Quality Assurance Organization (PQAO) to help lower the QA burden on SLT agencies and provide adequate level of independence Measurement quality objectives (MQOs) changing for gaseous pollutants

EPA Precursor Gas Training Workshop Gas Instrument QA Requirements* * Table A-2 is from 40 CFR 58, Appendix A

EPA Precursor Gas Training Workshop MQOs for Gas Pollutants Has Changed Ozone: –Coefficient of Variation (CV): 7% –Bias: +/- 7% SO2, NO2, CO: – CV: 10% –Bias: +/-10% For PM: –No Changes Nationally, 97% of all ozone monitors report Coefficient Variance of less than 7%.

EPA Precursor Gas Training Workshop “Reporting Organization” vs. “Primary Quality Assurance Organization” What’s the Difference? –RO: “an entity, such as State, local or Tribal monitoring organization that collects and reports air quality data to EPA.” –PQAO: Monitoring Organization or “other” organization that is responsible for a set of stations that monitor the same pollutant and which data quality assessments can be pooled.” PQAOs are responsible for implementing QA

EPA Precursor Gas Training Workshop “Reporting Organization” vs. “Primary Quality Assurance Organization” (cont.) PQAO: –Measurement uncertainty “reasonably homogeneous” –Common team of field operators –Use of a common QAPP and SOPs –Oversight of QA functions –In some cases, RO will equal PQAO Must demonstrate both Adequacy and Independence

EPA Precursor Gas Training Workshop Adequacy Performing audits at 20% of monitoring sites/instruments Audit data submission to AQS TTP Delivery system Follow NPAP field/lab SOP critical performance criteria Audit gases that are NIST certified and validated at least once a year Validation/certification with the EPA NPAP program Incorporated in QAPP

EPA Precursor Gas Training Workshop Independence No part of the organization is directly performing and accountable for the work being assessed (i.e., PQAO) Management structure that allow for the separation of its routine sampling personnel from its auditing personnel by two levels of management Submission of a plan demonstrating independence to the EPA Regional Office.

EPA Precursor Gas Training Workshop New Statistics in 40 CFR 58 Appendix A Focus Workgroup of the QA Strategy team formed to review and revise the old statistics in Appendix A Proposed that the stats be based on confidence intervals to meet the MQOs This approach allows flexibility for analyst and agencies to tighten or loosen their test if they meet criteria Allows analysts to look at “pooled” results rather than individual or small sets of data for which the old stats were designed For gases, both the precision and bias calculations use the bi-weekly QC 1-point check (i.e., Precision checks)

EPA Precursor Gas Training Workshop Precision and Bias : Monitor value : Target concentration (standard) : Percent Difference (individual bias) Estimates start the same way & both use the 1-point QC check

EPA Precursor Gas Training Workshop Precision * Where is the 10 th percentile of a Chi-Squared Distribution This represents a 90% upper confidence limit on the CV estimate “A measure of mutual agreement among individual measurements of the same property, usually under prescribed similar conditions”

EPA Precursor Gas Training Workshop Bias Absolute Bias Point Estimate: Where t 0.95,(n-1) is the 95th quantile of a Student’s t distribution with n-1 df and s d_abs is the standard deviation of the absolute value of the relative percent differences This represents a 95% upper confidence limit on the Bias estimate Absolute Bias Upper Bound: “A systematic or persistent distortion of a measurement process which causes errors in one direction”

EPA Precursor Gas Training Workshop P&B Guidance and Data Assessment Statistical Calculator (DASC) Software

EPA Precursor Gas Training Workshop AMP 255 Report –Monitoring Orgs. Can run this as often as they wish –OAQPS will run annually –Box–and-whisker plots included in annual summary

EPA Precursor Gas Training Workshop Data Quality Objectives for the Precursor Gases DQOs are used to create quality parameters so that the data collected is of sufficient quality for its use OAQPS staff began the DQO Process 1.5 years ago OAQPS staff employed Battelle Inc. to run simulation models to examine how the different QA indicators would affect data quality From these the Measurement Quality Objectives are defined

EPA Precursor Gas Training Workshop DQO Table for Precursor Gas Parameters Carbon Monoxide Urban Site Annual Completeness Hourly Measurement Precision (CV) Site- Specific Bias Power to Detect Annual Trend at a Single Site Power to Detect Annual Trend Across 50 Sites Multiplicative 1/2 Width for 95% Prediction Interval at an Individual Site Estimated Fraction of Data Falling in Prediction Interval 5% Reduction 10% Reduction 5% Reduction 10% Reduction Lower Bound Upper Bound 90%7%-20%5%-20%75%100% 9.627%70% 75%7%-20%5%-20%71%100% %75%

EPA Precursor Gas Training Workshop Burden’s Creek Station AAMG staff have been operating PG/trace gas instruments at BC for 2 years We have been operating like an NCore Station Since we perform 1-point QC tests, as described in 40 CFR 58, we can assess the data How do our results compare to the Battelle model?

EPA Precursor Gas Training Workshop Burden’s Creek MQOs (May 06 – April 07) Coefficient of Variance BiasData Completeness O3 API % CO–API % CO-TEI5.8+/ % NO-API % NOy-API % SO2-TEI3.6+/ %

EPA Precursor Gas Training Workshop NPAP for Precursor Gas Sites Precursor monitoring will be part of NPAP Monitoring organization are responsible for implementing adequate and independent audits –Allows for continued Federal implementation with STAG funds NPAP program testing TTP capabilities for precursor gasses at Burdens Creek –Some equipment still being purchased –Expected testing in 1 st quarter 2007

EPA Precursor Gas Training Workshop Expansion of Audit Levels Low levels added to accommodate Trace Level Instruments At Least three consecutive audit levels The audit levels selected should represent or bracket 80 percent of ambient concentrations

EPA Precursor Gas Training Workshop Summary 40 CFR 58 Appendix A regulations have changed PQAOs vs. ROs There are new statistical calculations –New Tools to assist EPA and stakeholders EPA has performed a DQO modeling exercise The BC data illustrates that we can collect data with the MQOs NPAP TTP audit vehicles are now gearing up