Ongoing Model Updates and Related Activities for NAAQS Compliance

1. Ongoing Model Updates and Related Activities for NAAQS Compliance 2012 Region 4 Modelers Workshop Region 4 Office, Atlanta, GA George M. Bridgers OAQPS-AQAD-Air Quality Modeling Group U.S. Environmental Protection Agency

2. Need for Agency to Address Chemistry under Appendix W • Sierra Club filed a lawsuit against EPA on August 31, 2011 alleging that EPA is unreasonably delayed in : • responding to an administrative petition for rulemaking to identify air quality models for ozone and PM2.5 to use in evaluating applications for PSD permits under the Clean Air Act, and • taking action required under the Clean Air Act §165(e)(3)(D) to designate such models through rulemaking. • Gina McCarthy letter on January 4, 2012 granting Sierra Club petition . . . • to engage in rule making to evaluate updates to Appendix W and, as appropriate, incorporate new analytical techniques or models for ozone and secondary PM2.5. • use the existing process and procedures under Section 320 of the Clean Air Act (CAA) to complete the appropriate rulemaking process to update Appendix W. U.S. Environmental Protection Agency

3. 10th Conference on Air Quality Modeling • Three day conference on regulatory air quality modeling held in RTP, NC on March 13-15, 2012. • Clean Air Act mandated (Section 320) conference that has a projected frequency of every 3 years. • Public forum for the regulatory, regulated, and research communities to meet and discuss all aspects of the regulatory air quality models and modeling techniques as well as engage on needed updates and amendments to the Guideline on Air Quality Models (Appendix W to 40 CFR Part 51). U.S. Environmental Protection Agency

4. 10th Conference on Air Quality Modeling • Day 1 and 2 of the conference included presentations by EPA and invited speakers on the current status of the regulatory air quality models, areas of model development, and emerging models and modeling techniques. • Day 3 was a full day of public comment and presentation. • Conference website posted on EPA’s SCRAM website: • http://www.epa.gov/ttn/scram/10thmodconf.htm U.S. Environmental Protection Agency

5. 10th Conference on Air Quality Modeling • Presentations posted immediately after conference: • http://www.epa.gov/ttn/scram/10thmodconfpres.htm • Full transcription posted on June 21, 2012: • http://www.epa.gov/ttn/scram/10thmodconf.htm(Follow Links) • Summary of Comments document including an overview of next steps and action items posted on October 5, 2012: • http://www.epa.gov/ttn/scram/10thmodconf/10thMC_Summary_of_Comments-Revised_10-05-2012.pdf • Response to Comments document projected for delivery at the end of the calendar year 2012. U.S. Environmental Protection Agency

6. Formal plan for updates to Appendix W • Goal to have a draft plan available in early 2013. • Discussion at A&WMA specialty conference and the 2013 RSL Modelers’ Workshop in spring 2013 (Information on these meetings on next slide). • Revised draft plan based on engagement and feedback available soon thereafter. • Rule making proposal for language amendments and updates to Appendix W released for public comment and response in connection with the 11th Conference on Air Quality Modeling(late 2014 / early 2015). • Coordination with AQPD on harmonizing the App W rulemaking with associated NSR/PSD implementation rulemaking, e.g., address SERs/SILs/SMCs, Increment, other issues) U.S. Environmental Protection Agency

7. Upcoming Conferences / Workshops • 2013 A&WMA Specialty Conference: • “Guideline on Air Quality Models: The Path Forward” • March 19-21, 2013, Sheraton Raleigh Hotel, Raleigh, NC. • http://boilermact.awma.org/wp-content/uploads/2012/09/AQ_Models_CFA.pdf • 2013 Regional, State, and Local Modelers’ Workshop: • April 22-25, 2013, EPA’s Region 6 office in Dallas, TX. • Open (regulatory, industrial, consultant / contractor, environmental, public) participation day on Tuesday, April 23. • Workshop information will be posted on EPA’s SCRAM website in December 2012 or early January 2013. U.S. Environmental Protection Agency

8. Interagency Workgroup on Air Quality Modeling (IWAQM) Phase III Effort • IWAQM was originally formed in 1991 to provide a focus for development of technically sound regional air quality models for regulatory assessments of pollutant source impacts on Federal Class I areas. • Phase 1 consisted of reviewing EPA guidance and recommending an interim modeling approach to meet the immediate need for a LRT model for ongoing permitting activity • Phase 2 report provided a series of recommendations concerning the application of the CALPUFF model for use in long range transport (LRT) modeling that informed EPA’s promulgation in 2003 of CALPUFF. • Phase 3 focus on next generation model to meet Federal program needs such as • Single source ozone and secondary PM2.5 • AQRVs (visibility and deposition) • Latest efforts by EPA and FLMs reported during 10th Modeling Conference session on “Emerging Models and Techniques” U.S. Environmental Protection Agency

9. IWAQM Phase 3: Initial Products • Complete development, documentation and evaluation of the Mesoscale Model Interface (MMIF) program • Converts MM5 or WRF meteorological output to CALPUFF, AERMOD, and SCICHEM-ready meteorological inputs • Document LRT model evaluation against tracer test data for CALPUFF (CALMET & MMIF), HYSPLIT, FLEXPART, SCIPUFF/SCICHEM, CMAQ and CAMx • 1992 European Tracer Experiment (ETEX) • 1983 Cross-Appalachian Tracer Experiment (CAPTEX) • 1980 Great Plains Tracer Experiment (GR80) • 1975 Savannah River Laboratory (SRL75) • Comparison of single-source estimation techniques for O3 & AQRV • 2006 Eastern Utah and western Colorado (UT-CO) 12 m domain • 2005 Four Corners Air Quality Task Force (FCAQRF) 12/4 km domain • Plume chemistry model evaluation (SCICHEM, CMAQ, etc) • TVA Cumberland Plume 1999 Southern Oxidant Study • 2000 TexAQS Aircraft Measurements U.S. Environmental Protection Agency

10. AERMOD Modeling System Updates • Updates based on comments received through the 10th Modeling Conference and other engagements, previously identified needs, and ongoing feedback from the regulated modeling community. • Near-term (updated release in late November): • Addition of a minimum wind speed threshold option for 1-min ASOS wind data in AERMET (to be addressed in pending Clarification Memo). • A few bug fixes to AERMET and minor enhancements. U.S. Environmental Protection Agency

11. AERMOD Modeling System Updates • Near-term – Continued: • “Beta option” in AERMET addressing "low wind speed" issue based on review of 10th Modeling Conference comments input from AERMIC committee and other published literature. • EPA evaluations demonstrating appropriateness and improved performance as compared to API/AECOM proposal. • Potential changes to AERMOD related to “low wind speed” issue also being evaluated. • Considering updates incorporating EPA's ORD development of enhanced line-source characterization and algorithm focused on near-road environment. • ORD delivered drafts of A-LINE (previously called AERLINE) to the Air Quality Modeling Group on 9/19/12. • AQMG coordinated review and comment across OAR (e.g., OTAQ) and continuing interactions with ORD on this research effort. U.S. Environmental Protection Agency

12. AERMOD Modeling System Updates • Longer-term (FY13+): • Reviewing issues with building characterization and downwash algorithms, seeking ORD support for wind tunnel andrelated research. • Reviewing issues and options for NO2 chemistry in AERMOD. • Potential enhancement to include buoyant line source option in AERMOD, as alternative to current BLP model. • Further evaluation of AERMOD-COARE and potential platform downwash option in AERMOD to address offshore sources, as an alternative to current OCD model, in coordination with Region 10. • Evaluation of prognostic meteorological data processing tool (MMIF) for application in AERMOD. MMIF would allow the use of meteorological models to generate the necessary representative meteorological data for near-field dispersion / NAAQS compliance demonstrations. U.S. Environmental Protection Agency

13. CALPUFF Modeling System Updates • EPA’s regulatory CALPUFF version 5.8 Modeling System updated to include newer version of the post processing program, CALPOST, on August 27, 2012: • CALPOST version 6.221 (level 080724) includes the "Method 8" IMPROVE equation revision per the Federal Land Managers' Air Quality Related Values Work Group (FLAG) revised October 2010 Phase 1 Report. • http://www.epa.gov/ttn/scram/dispersion_prefrec.htm#calpuff • Updates to the regulatory CALPUFF version 5.8 to address known bug fixes • Met with Federal Land Managers and working to modify and test code updates for provision to TRC by the end of 2012. • Next steps (FY13+) are to evaluate models (CALPUFF, CAMX, etc.) as eventual replacement for CALPUFF to deal with chemistry for PM2.5 & Ozone. U.S. Environmental Protection Agency

14. SO2 NAAQS Activities • Reviewing 09/2012 beta release of EPRI funded variable emissions tool, EMVAP, and related programs for consideration as part of future state attainment demonstrations in determining enforceable limits: • Planning discussions with EPRI immediately following the CMAS conference in October 2012. • http://sourceforge.net/projects/epri-dispersion/ • Updating SO2 SIP modeling guidance for attainment demonstrations (late 2012 / early 2013). U.S. Environmental Protection Agency

15. SO2 NAAQS Activities • Review and comments on evaluations of AERMOD modeling of current SO2 sources, ongoing with updated reports by states and/or EPA presentations in future. U.S. Environmental Protection Agency

16. NO2 NAAQS Activities • Released NO2 In-Stack Ratio (ISR) database on EPA’s SCRAM website on August 30, 2012: • Completed through small workgroup of EPA, state, and local agency modelers. • http://www.epa.gov/ttn/scram/no2_isr_database.htm • Continue working with API and their contractors on ARM2 as a modified NO2 Tier 2 method: • Reviewing documentation and evaluations, awaiting updates with specifics on how to implement within AERMOD. • Upon full receipt, EPA will independently verify evaluations and, as appropriate, write a guidance memorandum on how ARM2 may be used for permitting applications. U.S. Environmental Protection Agency

17. NO2 NAAQS Activities • Engaging with stakeholders on evaluations of NO2 Tier 3 approaches of OLM and PVMRM (longer term). • Advocating for new field studies to allow more full evaluation so these Tier 3 approaches could be characterized as refined methods as part of the planned regulatory update to Appendix W. U.S. Environmental Protection Agency

18. PM2.5 NAAQS Activities • Completed technical memorandum demonstrating basis for surrogacy policy to address PSD requirements of potential secondary visibility index standards as part of proposed PM2.5 NAAQS. • Completing draft PM2.5 Permit Modeling Guidance: • Public release by December 14thwith final PM NAAQS rule. • Allow for public comments on draft guidance document prior to “finalizing” in early 2013. • Discussions on SCICHEM and CMAQ-APT with EPRI and contractors (Sage Management & Environ) during CMAS conference in October 2012. U.S. Environmental Protection Agency

19. Roadway Modeling Activities w/ OTAQ • PM Hot Spot Conformity requirements take effect in December, requiring project level modeling for many new roadway projects: • Reviewed and commented on preliminary Hot Spot analysis submitted by state DOTs. • Reviewed CAL3QHCR model updates submitted by FHWA but significant concerns were noted with their submittal. • In parallel, AQMG is making updates to CAL3QHCR to meet conformity requirements and will be consistent with what EPA-FHWA has used in the PM hot-spot training. • Reviewed and commented on AERMOD and CAL3QHCR comparisons completed by FHWA. U.S. Environmental Protection Agency

20. Roadway Modeling Activities w/ OTAQ • Planned updates to Conformity guidance for annual NAAQS occurring in the next 2 months. • Review and comment to Region 9 on NEPA EIA modeling for I-710 freeway expansion project • Central coordination w/ ORD on research efforts • As mentioned previously, reviewing formulation and documentation of their new line source model, A-LINE (formerly AERLINE). • Evaluation of the line source algorithm/model for potential implementation into AERMOD. • Ultimate determination of what Appendix W updates are necessary to appropriate address dispersion modeling of mobile & related sources. U.S. Environmental Protection Agency

21. Planned Clarification Memorandum • Meteorological data and use of AERMINUTE: • Recommend 0.5 m/s wind speed threshold option for 1-min ASOS wind data consistent with site-specific met guidance. • To be issued with the near-term AERMOD package update. • GEP stack height changes in AERMOD: • Legal and policy basis for change. • Release late 2012 or early 2013. • Monitoring in lieu of modeling under Section 10 of Appendix W: • Clarify key criteria to be met and issues to be addressed. • Release late 2012 or early 2013. U.S. Environmental Protection Agency

22. Planned Clarification Memorandum • Further clarifications on Appendix W guidance regarding inventory of modeled sources and extent of modeling domain: • More detailed discussion and examples of “significant concentration gradient” criterion for identifying “nearby” sources for permitting under PM2.5 and 1-hour NAAQS. • Discussion of Appendix W guidance for extent of modeling domain and receptor placement and issues related to use of Significant Impact Levels (SILs) in compliance demonstrations • Further debunk Draft NSR Workshop Manual (aka “Puzzle Book”) as basis for NSR/PSD permit modeling. • Release early 2013. U.S. Environmental Protection Agency

23. Fugitives Source Characterization • Continued review of the comments at the 10th Modeling Conference (NMA and related): • Aforementioned Response to Comments document and formal plan for Appendix W updates (late 2012 / early 2013). • Continued investigation of comments related to “Low wind speed” issue: • AERMET minimum wind speed threshold option. • AERMOD “beta option” for addressing low wind speeds. • Additional evaluation of AERMOD with low wind speed databases and field study information. • Further consideration of the final recommendations from the Haul Roads Workgroup. U.S. Environmental Protection Agency

24. Questions and Comments • George M. Bridgersbridgers.george@epa.gov919-541-5563 • Tyler Foxfox.tyler@epa.gov919-541-5562 U.S. Environmental Protection Agency

25. Action Items from Conference Fact Checking Previously Proposed Timelines U.S. Environmental Protection Agency

26. Current Action Items: AERMOD • Clarification memo on GEP stack height and on AERMINUTE/AERMET to establish minimum wind speed threshold • Follow up on low wind speed and downwash issues with stakeholder community (including EPA’s ORD) to determine possible model formulation updates • Consider near-term options for updates to NO2 Tier 2 ambient ratio method based on API sponsored approach, i.e., ARM2. • Continue work with community on evaluation of NO2 Tier 3 techniques (OLM and PVMRM) and discuss potential for new field studies • Work with modeling community on development of NO/NO2 in-stack ratio database U.S. Environmental Protection Agency

27. Current Action Items: AERMOD Soon to be released with AERMOD/AERMET update • Clarification memo on GEP stack height and on AERMINUTE/AERMET to establish minimum wind speed threshold • Follow up on low wind speed and downwash issues with stakeholder community (including EPA’s ORD) to determine possible model formulation updates • Consider near-term options for updates to NO2 Tier 2 ambient ratio method based on API sponsored approach, i.e., ARM2. • Continue work with community on evaluation of NO2 Tier 3 techniques (OLM and PVMRM) and discuss potential for new field studies • Work with modeling community on development of NO/NO2 in-stack ratio database Threshold and beta u* additions focus of model updates and recent engagements with EPA-ORD Ongoing interactions with API and their contractors Some energy with WESTAR, engagements with industry, and A&WMA specialty conference ISR database released on SCRAM at end of summer… still no formal submissions by community U.S. Environmental Protection Agency

28. Current Action Items: CALPUFF • Discussed ‘bug fixes’ with FLMs in early April and now working to address them in updated regulatory version of modeling system • Conduct assessment with update tool to determine implications • Document assessment and work with TRC (model developer) to formally release updated model code and documentation U.S. Environmental Protection Agency

29. Current Action Items: CALPUFF Ongoing coordination with TRC, but OAQPS is moving forward with incorporating the appropriate bug fixes in the current release version (v5.8) of CALPUFF. Formal release scheduled for early 2013 depending on full delivery from contractor and completing proper evaluations and documentation. • Discussed ‘bug fixes’ with FLMs in early April and now working to address them in updated regulatory version of modeling system • Conduct assessment with update tool to determine implications • Document assessment and work with TRC (model developer) to formally release updated model code and documentation U.S. Environmental Protection Agency

30. Ongoing Agency Activities • Emphasize flexibility in existing guidance (e.g., post-construction monitoring) and issue new guidance as necessary for new 1-hour NAAQS permitting and implementation and to address reactive pollutants • Continue working with co-regulators and stakeholders especially through workgroups: • AERMOD implementation workgroup (AIWG) focusing on issues with model demonstrations of compliance for NO2 and SO2 • Technical Workgroup of stakeholders that assisted EPA in planning agenda and speakers for 10th Modeling Conference with plans to continue for improved communication/coordination • Interagency Workgroup on Air Quality Models (IWAQM) focusing on next generation model(s) to meet Federal program needs U.S. Environmental Protection Agency

31. Ongoing Agency Activities Ongoing… • Emphasize flexibility in existing guidance (e.g., post-construction monitoring) and issue new guidance as necessary for new 1-hour NAAQS permitting and implementation and to address reactive pollutants • Continue working with co-regulators and stakeholders especially through workgroups: • AERMOD implementation workgroup (AIWG) focusing on issues with model demonstrations of compliance for NO2 and SO2 • Technical Workgroup of stakeholders that assisted EPA in planning agenda and speakers for 10th Modeling Conference with plans to continue for improved communication/coordination • Interagency Workgroup on Air Quality Models (IWAQM) focusing on next generation model(s) to meet Federal program needs Some additional AWIG work over the summer Limited engagements over the summer… next call will be in mid-November Need for formal interactions on heels of CMAS… U.S. Environmental Protection Agency

32. Immediate Next Steps • Post additional LRT evaluation reports to SCRAM by mid-May • Release the draft PM2.5 Permit Modeling Guidance for comment and review • Public comment period has been extended through June 15, 2012 • Public comment summary & response to comment document under development(Joe Tikvart is assisting the AQMG) U.S. Environmental Protection Agency

33. Immediate Next Steps Unable to post due to deficiencies / issues in reports • Post additional LRT evaluation reports to SCRAM by mid-May • Release the draft PM2.5 Permit Modeling Guidance for comment and review • Public comment period has been extended through June 15, 2012 • Public comment summary & response to comment document under development(Joe Tikvart is assisting the AQMG) Well overdue… “very soon” It was and we ultimately received 38 well developed formal comments Release of Comment Summary document a few weeks back and Response to Comment document getting underway U.S. Environmental Protection Agency