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Support Center for Regulatory Atmospheric Modeling (SCRAM)

Air Modeling - Announcements

07/11/17 – An Informational Webinar (28 pp, 522 KB, About PDF) regarding the establishment of appropriate Modeling Domain, Source Data, and Background Concentrations under Section 8 of the revised Guideline on Air Quality Models is available for reference.

07/11/17 – The Informational Webinar (7 pp, 337 KB, About PDF) regarding O3 and Secondary PM2.5 assessments under Section 5 of the revised Guideline of Air Quality Models is available for reference.

06/05/17 - A revised version of the AERMOD Model Formulation and Evaluation Document (238 pp, 5.8 M, About PDF) is available. The revision includes an appendix evaluating low wind model performance.

05/26/17 - A Compilation of Comments document (182 pp, 11.5 MB, About PDF) regarding the Draft Guidance on the Development of Modeled Emission Rates for Precursors (MERPs) as a Tier 1 Demonstration Tool for Ozone and PM2.5 under the PSD Permitting Program (79 pp, 1.6 MB, About PDF) is now available. The February 23, Data Distribution and Errata memorandum (6 pp, 476 KB, About PDF) and the January 19, Draft MERPs Guidance Webinar presenation (27 pp, 294 KB, About PDF) are also available for reference.

05/26/17 - A Compilation of Comments document (43 pp, 5.2 MB, About PDF) regarding the Draft PM2.5 Precursor Demonstration Guidance is now available.

05/22/17 - The final revisions to the Guideline on Air Quality Models, as published in the Federal Register on January 17, 2017, are now effective. An Informational Webinar presentation (83 pp, 1.1 MB, About PDF), presented on February 16, is also available for reference.

03/21/17 - The Informational Webinar (42 pp, 2.5 MB, About PDF) regarding the use of prognostic met data for NSR permit modeling and specifically the EPA’s Mesoscale Model InterFace (MMIF) is available for reference.

03/08/17Clarification Memorandum (4 pp, 357 KB, About PDF) on the AERMOD Modeling System version for use in SO2 implementation efforts and other regulatory actions.

12/06/16 - The presentationsExit from the 2016 EPA Regional, State, and Local Modelers' Workshop are now available.

08/18/16 A webinar regarding the Draft O3 and PM2.5 SILs Guidance for PSD Program (Slides from the webinar available on this webpage.) will be conducted on Wednesday, August 24, 2016 from 2:00p to 3:30p EDT.

08/04/16 The draft SOModeling Technical Assistance Document (PDF) has been updated to clarify receptor placement and the minimum number of years to model.

08/01/16 The Draft Guidance on SILs for Ozone and PM2.5 in PSD has been posted on the NSR Permitting website along with supporting documentation. The EPA will accept public comment on the draft guidance package through Septemebr 30, 2016.

07/26/16 Updated regulatory versions of CALPUFF and CALMET (version 5.8.5, dated 151214) are now available. The links to the updated CALPUFF Modeling System files, the associated Model Change Bulletin (MCB-H) can be found on the CALPUFF webpage.

12/10/15 A Clarification on the Approval Process for Regulatory Application of the AERMOD Modeling System Beta Options memorandum is now available. This memo discusses the appropriate process for the approval of the AERMOD Modeling System with the use of various beta options for regulatory applications.

12/04/14 The Draft Modeling Guidance for Demonstrating Attainment of Air Quality Goals for Ozone, PM2s, and Regional Haze is now available for consideration, review, and comment. This document is a revision to the previous modeling guidance which was released in April 2007.

04/08/14 Interim guidance for the treatment of condensable particulate matter test results in the PSD and NSR permitting programs is now available.

01/14/14 The draft SO2Monitoring and Modeling Technical Assistance Documents have been updated based on public comments and are available on the Sulfur Dioxide Implementation web page.

08/26/13 The NO2/NOx In-Stack Ratio (ISR) Database has been updated based on the first database submission from the State of Oklahoma and the second database submission from the State of Alaska.