2019-17305. Conference on Air Quality Modeling

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice of conference.

SUMMARY:

The Environmental Protection Agency (EPA) announces its Twelfth Conference on Air Quality Modeling. Such a conference is required by section 320 of the Clean Air Act (CAA) to be held every 3 years. The purposes of the Twelfth Conference are to provide an overview of the latest features of the currently preferred air quality models and to provide a forum for public review and comment on potential revisions to the way the Agency determines and applies the appropriate air quality models in the future.

DATES:

Comments: Comments on potential revisions to the way the Agency determines and applies the appropriate air quality models must be received on or before November 4, 2019.

Conference: The conference will be held on October 2 through 3, 2019, from 8:30 a.m. to 5:00 p.m. Requests to speak at the conference should be submitted to the individual listed below in the FOR FURTHER INFORMATION CONTACT section by September 13, 2019.

ADDRESSES:

Comments: Submit your comments, identified by Docket ID No. EPA-HQ-OAR-2019-0454 by one of the following methods:

• http://www.regulations.gov: Follow the on-line instructions for submitting comments. This is the EPA's preferred method for receiving comments.
• Email: Comments may be sent by electronic mail (email) to [e-mail], Attention Docket ID No. EPA-HQ-OAR-2019-0454.
• Fax: Fax your comments to [phone], Attention Docket ID No. EPA-HQ-OAR-2019-0454.
• Mail: Send your comments to: Air and Radiation Docket and Information Center, Environmental Protection Agency, Mailcode: 2822T, 1200 Pennsylvania Ave. NW, Washington, DC 20460, Attention Docket ID No. EPA-HQ-OAR-2019-0454.
• Hand delivery or courier: Deliver your comments to EPA Docket Center, 1301 Constitution Ave. NW, Room 3334, Washington, DC. Such deliveries are only accepted during the Docket's normal hours of operation, and special arrangements should be made for deliveries of boxed information.

Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-2019-0454. The EPA's policy is that all comments received will be included in the public docket without change and may be made available online at http://www.regulations.gov,, including any personal information provided, unless the comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit information that you consider to be CBI or otherwise protected through http://www.regulations.gov or email. The http://www.regulations.gov website is an “anonymous access” system, which means the EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an email comment directly to the EPA without going through http://www.regulations.gov,, your email address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the internet. If you submit an electronic comment, the EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD-ROM you submit. If the EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, the EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses. For additional information about the EPA's public docket, visit the EPA Docket Center homepage at http://www.epa.gov/​epahome/​dockets.htm.

Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some information is not publicly available, e.g., CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, will be publicly available only in hard copy form. Publicly available docket materials are available either electronically in http://www.regulations.gov or in hard copy at the Air Docket in the EPA Docket Center, EPA West, Room 3334, 1301 Constitution Ave. NW, Washington, DC. This Docket Facility is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The Docket telephone number is [phone]; fax [phone].

FOR FURTHER INFORMATION CONTACT:

George Bridgers, Environmental Protection Agency, Office of Air Quality Planning and Standards, Air Quality Assessment Division, Mail Code C439-01, Research Triangle Park, NC 27711; telephone: [phone]; fax: [phone]; email address: [e-mail].

SUPPLEMENTARY INFORMATION:

I. General Information

A. Written Comments

Submit your comments, identified by Docket ID No. EPA-HQ-OAR-2019-0454, at https://www.regulations.gov (our preferred method), or the other methods identified in the ADDRESSES section. Once submitted, comments cannot be edited or removed from the docket. The EPA may publish any comment received to its public docket. Do not submit electronically any information you consider to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. The EPA will generally not consider comments or comment contents located outside of the primary submission (i.e., on the Web, cloud, or other file sharing system). For additional submission methods, the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit https://www.epa.gov/​dockets/​commenting-epa-dockets.

Submitting CBI: Clearly mark the part or all of the information that you claim to be CBI. For CBI information in a disk or CD-ROM that you mail to the EPA, mark the outside of the disk or CD-ROM as CBI and then identify electronically within the disk or CD-ROM the specific information that is claimed as CBI. In addition to one complete version of the comment that includes information claimed as CBI, a copy of the comment that does not contain the information claimed as CBI must be submitted for inclusion in the public docket. Information marked as CBI will not be disclosed except in accordance with procedures set forth in Title 40 Code of Federal Regulations (CFR) part 2.

Do not submit information that you consider to be CBI or otherwise protected through http://www.regulations.gov or email. Send or deliver information identified as CBI to only the following address: OAQPS Document Control Officer (Room C404-02), U.S. EPA, Research Triangle Park, NC 27711, Attention Docket ID No. EPA-HQ-OAR-2019-0454.

If you have any questions about CBI or the procedures for claiming CBI, please consult the person identified in the FOR FURTHER INFORMATION CONTACT section.

Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some information is not publicly available, e.g., CBI (Confidential Business Information) or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, will be publicly available only in hard copy. Publicly available docket materials are available either electronically in http://www.regulations.gov or in hard copy at the EPA Docket Center, EPA/DC, EPA WJC West Building, Room 3334, 1301 Constitution Ave. NW, Washington, DC. This Docket Facility is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is [phone], and the telephone number for the Air Docket is [phone].

B. Background Information

Additional information and a more detailed agenda are electronically available at https://www.epa.gov/​scram/​12th-conference-air-quality-modeling.

C. Conference

The conference will be held in the EPA Auditorium, Room C111, 109 T.W. Alexander Drive, Research Triangle Park, NC 27711.

II. Background

The Guideline on Air Quality Models (Guideline), which is found in Appendix W to 40 CFR (Code of Federal Regulations) part 51, is used by the EPA, other federal, state, territorial, local, and tribal air quality agencies, and industry to prepare and review new or modified source permits, State Implementation Plan (SIP) submittals or revisions, conformity, and other air quality assessments required under the CAA and EPA regulations. The Guideline serves as a means by which national consistency is maintained in air quality analyses for regulatory activities under 40 CFR 51.112, 51.117, 51.150, 51.160, 51.165, 51.166, 52.21, 93.116, 93.123, and 93.150.

The EPA originally published the Guideline in April 1978 (EPA-450/2-78-027), and it was incorporated by reference in the regulations for the PSD program in June 1978. The EPA revised the Guideline in 1986 (51 FR 32176), and updated it with supplement A in 1987 (53 FR 32081), supplement B in July 1993 (58 FR 38816), and supplement C in August 1995 (60 FR 40465). The EPA published the Guideline as appendix W to 40 CFR part 51 when the EPA issued supplement B. The EPA republished the Guideline in August 1996 (61 FR 41838) to adopt the CFR system for labeling paragraphs. Subsequently, the EPA revised the Guideline on April 15, 2003 (68 FR 18440), to adopt CALPUFF as the preferred model for long-range transport of emissions from 50 to several hundred kilometers (km) and to make various editorial changes to update and reorganize information and remove obsolete models. The EPA further revised the Guideline on November 9, 2005 (70 FR 68218), to adopt AERMOD as the preferred model for near-field dispersion of emissions for distances up to 50 km. The publication and incorporation of the Guideline into the EPA's Prevention of Significant Deterioration (PSD) regulations satisfies the requirement under CAA section 165(e)(3) for the EPA to promulgate regulations that specify, with reasonable particularity, models to be used under specified sets of conditions for purposes of the PSD program.

On July 29, 2015, the EPA proposed the revisions to the Guideline in the Federal Register (80 FR 45340). To inform the development of these proposed revisions to the Guideline and in compliance with CAA section 320, the EPA held the Tenth Conference on Air Quality Modeling in March 2012. The conference addressed updates on (1) the regulatory status and future development of AERMOD and CALPUFF; (2) review of the Mesoscale Model Interface (MMIF) prognostic meteorological data processing tool for dispersion models; (3) draft modeling guidance for compliance demonstrations of the fine particulate matter (PM_2.5) National Ambient Air Quality Standards (NAAQS); (4) modeling for compliance demonstration of the 1-hour nitrogen dioxide (NO₂) and sulfur dioxide (SO₂) NAAQS; and (5) new and emerging models/techniques for future consideration under the Guideline to address single-source modeling for ozone and secondary PM_2.5, as well as long-range transport and chemistry. Based on comments received from stakeholders at the Tenth Modeling Conference, “Phase 3” of the Interagency Workgroup on Air Quality Modeling (IWAQM) was formalized in June 2013 to provide additional guidance for modeling single-source impacts on secondarily formed pollutants (e.g., ozone and PM_2.5) in the near-field and for long-range transport. A transcript of the conference proceedings and a summary of the public comments received are available in the docket for the Tenth Modeling Conference (Docket ID No. EPA-HQ-OAR-2012-0056). Additionally, all of the materials associated with this conference are available on the EPA's SCRAM website at https://www3.epa.gov/​ttn/​scram/​10thmodconf.htm.

The Eleventh Conference on Air Quality Modeling was held August 12-13, 2015, in continuing compliance with CAA section 320. This conference included the public hearing for the proposed revisions to the Guideline. It began with a thorough overview of these proposed revisions, including presentations from EPA staff on the formulation updates to the preferred models and the research and technical evaluations that support these and other revisions. Specifically, there were presentations summarizing the proposed updates to the AERMOD modeling system; replacement of CALINE3 with AERMOD for modeling of mobile sources; incorporation of prognostic meteorological data for use in dispersion modeling; the proposed screening approach for long-range transport for NAAQS and PSD increments assessments with use of CALPUFF as a screening technique rather than an EPA-preferred model; the proposed 2-tiered screening approach to address ozone and PM_2.5 in PSD compliance demonstrations; the status and role of the Model Clearinghouse; and updates to procedures for single-source and cumulative modeling analyses (e.g., modeling domain, source input data, background data, and compliance demonstration procedures). At the conclusion of these presentations, the public hearing on the proposed revisions to the Guideline was convened. The EPA presentations and the presentations from the public hearing, along with the transcript of the conference proceedings, are available in the docket for the Eleventh Modeling Conference (Docket ID No. EPA-HQ-OAR-2015-0310). Additionally, all of the materials associated with the Eleventh Modeling Conference and the public hearing are available on the EPA's SCRAM website at https://www3.epa.gov/​ttn/​scram/​11thmodconf.htm.

The 2015 proposed revisions to the Guideline were finalized and published in the Federal Register (82 FR 5182) on January 17, 2017. Supporting information on this final rule is available on the EPA's SCRAM website at https://www3.epa.gov/​ttn/​scram/​appendix_​w-2016.htm and a direct link to the final rule publication is https://www3.epa.gov/​ttn/​scram/​guidance/​guide/​appw_​17.pdf.

III. Public Participation

The Twelfth Conference on Air Quality Modeling will be open to the public; no admission fee is charged and there is no formal registration. The conference will begin the first morning with introductory remarks by the presiding EPA official. The following topics will be presented:

1. Conference overview;

2. Currently preferred air quality models status and updates;

3. Expert panel discussions and invited presentations on model/technique enhancements:

• Treatment of low wind conditions
• Building downwash
• Mobile source modeling
• Overwater modeling
• Prognostic meteorological data
• Near-field and long-range model evaluation criteria
• NO₂ modeling techniques
• Single source O₃ and PM_2.5 modeling techniques
• Plume rise;

4. Model Clearinghouse and modeling guidance updates; and

5. Other presentations by the public.

Those wishing to speak at the conference, whether to volunteer a presentation on a special topic or to offer general comment on any of the modeling techniques scheduled for presentation, should contact us at the address given in the FOR FURTHER INFORMATION CONTACT section (note the cutoff date). Such persons should identify the organization (if any) on whose behalf they are speaking and the length of the presentation. If a presentation of general comments is projected to be longer than 10 minutes, the presenter should also state why a longer period is needed. Persons failing to submit a written notice but desiring to speak at the conference should notify the presiding officer immediately before the conference, and they will be scheduled on a time-available basis.

The conference will be conducted informally and chaired by an EPA official. There will be no sworn testimony or cross examination. A verbatim transcript of the conference proceedings will be produced and placed in the docket. Speakers should bring extra copies of their presentation for inclusion in the docket and for the convenience of the recorder. Speakers will also be permitted to enter written comments into the record. Additional written statements or comments should be sent to the OAR Regulatory Docket (see ADDRESSES section). A transcript of the proceedings and a copy of all written comments will be maintained in Docket ID No. EPA-HQ-OAR-2019-0454, which will remain open until November 4, 2019, for the purpose of receiving additional comments.

Dated: August 2, 2019.

Panagiotis E. Tsirigotis,

Director, Office of Air Quality Planning and Standards.