ongoing model updates and related activities for naaqs compliance 2012 region 4 modelers workshop...

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

1U.S. Environmental Protection Agency11/13/2012

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.


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).


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


http://www.epa.gov/ttn/scram/10thmodconf.htm


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.


http://www.epa.gov/ttn/scram/10thmodconfpres.htm





http://www.epa.gov/ttn/scram/10thmodconf/10thMC_Summary_of_Comments-Revised_10-05-2012.pdf



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)


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 2013.7U.S. Environmental Protection Agency11/13/2012

http://boilermact.awma.org/wp-content/uploads/2012/09/AQ_Models_CFA.pdf



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”


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


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.


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.


AERMOD Modeling System Updates• Longer-term (FY13+):

– Reviewing issues with building characterization and downwash algorithms, seeking ORD support for wind tunnel and related 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.


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.


http://www.epa.gov/ttn/scram/dispersion_prefrec.htm



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).


http://sourceforge.net/projects/epri-dispersion/

http://sourceforge.net/projects/epri-dispersion/

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.


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.


http://www.epa.gov/ttn/scram/no2_isr_database.htm

http://www.epa.gov/ttn/scram/no2_isr_database.htm

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.


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 14th with 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.


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.


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.


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.


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.


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.


Questions and Comments

• George M. [email protected]

• Tyler [email protected]


mailto:[email protected]

mailto:[email protected]

Action Items from Conference

255/2/2012 U.S. Environmental Protection Agency

Fact Checking Previously Proposed Timelines

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


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


Soon to be released with AERMOD/AERMET update

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

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


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


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.

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


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


Ongoing…

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…

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)


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)


Unable to post due to deficiencies / issues in reports

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

ongoing model updates and related activities for naaqs compliance 2012 region 4 modelers workshop...

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