PM NAAQS Review Update

1. PM NAAQS Review Update Joseph Paisie Air Quality Strategies & Standards Division, Office of Air Quality Planning & Standards, EPA WESTAR Fall Business Meeting, San Diego, CA September 22, 2005

2. PM NAAQS Review: Process EPA Staff Paper: policy-relevant assessments leading to staff recommendations on standards Scientific studies related to health and environmental effects EPA Criteria Document: integrative assessment of scientific studies Scientific peer review of published studies Reviews by CASAC and the public Reviews by CASAC and the public We are here EPA final decision on standards EPA proposed decision on standards Public hearings and comments on proposal Interagency review

3. PM NAAQS Review: Schedule • Final PM Air Quality Criteria Document– October 2004 • Completion of PM Staff Paper: • Second draft – January 31, 2005 (for CASAC & public review) • CASAC review meetings April 6-7 and May 18, 2005 • Final PM Staff Paper -- June 30, 2005 • Rulemaking on PM NAAQS: • Federal Register proposal to be signed by December 20, 2005 • Public comment period: 90 days • Final Federal Register notice to be signed by September 27, 2006 • Simultaneous Rulemakings: • PM NAAQS, FRM, & Data Handling (Part 50) • Ambient Air Monitoring Regulations: Requirements for Reference and Equivalent Methods, Network Design Requirements (Parts 53 & 58) • Exceptional & Natural Events

4. Final Staff Paper Recommendations:Primary PM2.5 NAAQS • Consideration should be given to revising the current primary PM2.5 standards to provide increased public health protection from the effects of both long- and short-term exposures to fine particles. • Annual PM2.5 standard at the current level of 15 µg/m3 together with a revised 24-hour PM2.5 standard in the range of 35 to 25 µg/m3 OR • Revised annual PM2.5 standard, within the range of 14 to 12 µg/m3, together with a revised 24-hour PM2.5 standard in the range of 40 to 35 µg/m3, to provide supplemental protection against episodic localized or seasonal peaks

5. CASAC Recommendations:Primary PM2.5 NAAQS • CASAC found staff recommendations “scientifically well-reasoned” and advised that primary PM2.5 standards should be revised “to provide increased public health protection” • Consensus in agreement with staff recommendations that focused primarily on lowering the 24-hr PM2.5 standard • In addition, Panel “did not endorse the option of keeping the annual standard at its present level” • Most Panel members favored a 24-hr standard in the range of 35 to 30 µg/m3 together with a revised annual standard in the range of 14 to 13 µg/m3 • Most Panel members favored continued use of 98th percentile form, along with continued use of annual and 24-hour averaging times

6. Final Staff Paper Recommendations:Secondary PM2.5 NAAQS (Visibility) • Consideration should be given to revising the current suite of secondary PM2.5 standards to provide increased and more targeted protection, primarily in urban areas, from visibility impairment related to fine particles. • Consideration should be given to a 4- to 8-hour PM2.5 standard in the range of 30 to 20 µg/m3 to protect visual air quality primarily in urban areas. • A standard within these ranges could provide an appropriate degree of protection against visibility impairment, generally resulting in a visual range of 25 to 35 km, primarily in urban areas, as well as improved visual air quality in surrounding non-urban areas • Such a standard would complement the protection of visual air quality in Class I areas afforded by the Regional Haze Rule

7. CASAC Recommendations:Secondary PM2.5 NAAQS (Visibility) • CASAC found staff assessment to be well-conceived and strongly supported staff recommendation for a distinct secondary PM2.5 standard to protect urban visibility • CASAC supports the range of levels recommended by staff and consider it to be appropriate based on the existing data • Some members considered this range of levels to be high, yet recognized that additional studies would be needed to support a more specific and protective level • CASAC panel members recommended considering a 92nd to 98th percentile form, combined with a level toward the upper-end of the proposed range of 30 to 20 µg/m3

8. Final Staff Paper Recommendations:Primary PM10-2.5 (Coarse) NAAQS • The current primary PM10 standards should be revised in part by replacing the PM10 indicator with an indicator of urban thoracic coarse particles that does not include fine particles (UPM10-2.5). • Consideration should be given to setting a 24-hour UPM10-2.5 with a level in the range of approximately 50 to 70 µg/m3, 98th percentile form, or approximately 60 to 85 µg/m3, 99th percentile form. • Staff believes that a more precautionary approach would focus consideration on the lower end of these ranges, while consideration of a standard set toward the upper end of these ranges would place relatively more weight on the uncertainties inherent in the very limited epidemiologic evidence.

9. CASAC Recommendations:Primary PM10-2.5 (Coarse) NAAQS • Public Meeting (teleconference) with CASAC PM Review Panel held on August 11, 2005 • EPA waiting to receive final CASAC comments on portions of the final Staff Paper dealing with thoracic coarse particles (PM10-2.5)

10. For more information: • Staff paper, criteria document, risk assessment & technical documents available at: http://www.epa.gov/ttn/naaqs/standards/pm/s_pm_index.html • CASAC comments available at: http://www.epa.gov/sab/panels/casacpmpanel.html