Emissions Factors Improvement

1. Revising Critical Components to Streamline and Expand Program Applicability Emissions Factors Improvement Ron Myers OAQPS/SPPD/MPG 2/13/2008

2. EF Program Background • Dates to about 1968 (68 pages) • Managed by a small staff (5 to 15) • Highly variable and declining funding • Steadily increasing demands • Primarily uses secondary data • Reevaluated program in 2003

3. Presentation Topics • EF Uncertainty Analysis • The Electronic Reporting Tool • Web FIRE

4. Emissions Factors Uncertainty • Existing EF quality ratings are based on subjective assessments • Everyone uses only the average • No one considers the accuracy of their estimate or the potential implications

5. Background • Stakeholders, National Academy of Sciences, and the Office of Inspector General (www.epa.gov/oig/reports/air.htm) said EPA should better quantify the uncertainty of the emissions factors • Current Emissions Factors: • Developed using the mean, usually with few available data • Use a subjective letter system for rating quality

6. Factor Data Uncertainty Study • We assessed statistically the uncertainty in the best emissions factors in AP-42 • Criteria for selection of emissions factors: • data quality (A-rated) • data quantity > 15 emissions tests • number/type of pollutants • accessibility of supporting emissions data

7. Emissions Factor Data • We selected 44 A-rated data sets from: • Wood Residue Combustion • Refuse Combustion • Waferboard/Oriented Strandboard • Hot Mix Asphalt • Pollutants assessed included Particulate Matter, Sulfur Dioxide, Nitrogen Oxides, Carbon Monoxide, HAPs

8. Target Statistic = 10th percentile Median Mean Probability Target Statistic = 90th percentile Target Statistic = 95th percentile Emissions, lb/mmbtu x 10-1 Example Distribution

9. Findings • Best rated emissions factors had: • Log normal or Weibull distributions (not normal distributions) • More tests (with 3 runs per test) reduce uncertainty, diminishing returns on uncertainty after 10 tests • Uncontrolled HAPs show the greatest variability

10. Box & Whisker Percentiles 10% 90% 25% 75% CEMS Test & Monitor Single Test A Rated Factor B Rated Factor C Rated Factor D Rated Factor E Rated Factor 0 0.5 1 1.5 2 2.5 3 3.5 4 Range of Emissions Estimates

11. Next Steps • Presentation on study available at: http://www.epa.gov/ttn/chief/efpac/uncertainty.html • The comment period has closed and we are reviewing comments and may revise the report for publication.

12. The Electronic Reporting Tool (ERT) • Replaces paper source test reports • Uses Microsoft Access • Test Plan development • Test Plan evaluation • Imports field data from Excel • Stores lab data • Test reviewer component • Exports critical data to WEB FIRE

13. Compliance certification Permit applications or revisions Permit fee determination Emissions Inventory Performance Information Modeling Risk Assessment Environmental Justice Issues TRI – CERCLA – SARA AIRS AFS reporting Complaint Evaluations Test Report Uses

14. Benefits of ERT over paper • Improve coordination • Reduce duplicative work • Standardize reports • Improve information flow • Reduce storage space • Improve documentation • Improve & standardize QA

22. Capabilities of ERT • Current Pollutants • Metals – Halides • PM – THC • SOx – NOx • Future Pollutants • Dioxins – POM/PAH • http://www.epa.gov/ttn/chief/ert/ert_tool.html

23. Products of ERT • Improved documentation for evaluation of source test report • Export of critical values and documentation for use in Emissions Factors development in WebFIRE • Export of critical information into data flows for other program areas.

24. What is WEBFIRE • WebFIRE (Factor Information Retrieval System) is an internet based Cold Fusion application that combines AP-42, the Compilation of Air Pollutant Emission Factors, and FIRE. • WebFIRE is used by local, state, and federal agencies, environmental consultants and others who require emissions factor information for estimating criteria pollutants and air toxic emissions from stationary sources & area sources. • WebFIRE will display included and revoked EF’s for all EF available in AP-42 Compilation of Air Pollutant Emission Factors (AP-42 Fifth Edition).

25. Benefits of WEBFIRE • Updates can be made more frequently, keeping pace with updates to AP-42. • Allows for the addition of new source category codes (SCCs) and emissions factors for use in the EPA’s National Emission Inventories. • Replace the traditional report format of AP-42. AP-42 text will be the same, but the EF tables will be available in WEBFIRE. • Enable the Agency to update, revise, and revoke emission factors on a more real time basis rather than updating factors annually.

26. Future Upgrades to WEBFIRE • WebFIRE will have links to emission factor source test reports and supporting background reports to the database. • We have a spreadsheet that can be used in lieu of the ERT to allow users to manually extract info. from the source test reports and be imported into WebFIRE.

27. Future Upgrades to WEBFIRE • With this new linkage between emission test reports and emissions factors, WEBFIRE will gain the ability to calculate emissions factors on the fly. • WebFIRE will incorporate emission test results from the ERT or spreadsheet to allow users to tailor their emissions estimate using data selected from facilities that are more representative of their facility.

28. WebFIRE location • http://cfpub.epa.gov/oarweb/index.cfm?action=fire.main • Or for detailed search • http://cfpub.epa.gov/oarweb/index.cfm?action=fire.detailedSearch

29. Open Discussion • QUESTIONS? myers.ron@epa.gov (919) 541-5407