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DNR News Releases

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Updated Air Dispersion Modeling Guidance and Form MD Available

Updated Air Dispersion Modeling Guidance and Form MD Available

  • 8/25/2021 4:01:00 PM
  • View Count 1683
For those projects that may require modeling, DNR updated three guidance documents and Form MD. The updates remove references to the 24-hour and annual SO2 National Ambient Air Quality Standards (NAAQS), which have been revoked.
Plan to participate in the Air Quality Client Contact meeting on November 19

Plan to participate in the Air Quality Client Contact meeting on November 19

  • 11/9/2020 1:29:00 PM
  • View Count 1426
Stay up-to-date on current events and upcoming changes in DNR’s air quality program. Plan to attend an open forum with DNR staff at the Air Quality Client Contact Meeting at 1 p.m. on Thursday, November 19. The meeting can be accessed virtually and by teleconference.
DNR to Delay Implementation of Revised PM2.5 SILs

DNR to Delay Implementation of Revised PM2.5 SILs

  • 7/30/2018 8:29:00 AM
  • View Count 2652
On April 17, 2018 EPA released a memo titled “Guidance on Significant Impact Levels for Ozone and Fine Particles in the Prevention of Significant Deterioration Permitting Program.” In this guidance EPA recommended a 24-hour significant impact level (SIL) of 1.2 µg/m3 for particulate matter less than or equal to 2.5 microns in diameter (PM2.5), which is the same level as the previously proposed draft SIL
Opportunity for Comment: PM2.5 SILs and AAR Summary Web Page

Opportunity for Comment: PM2.5 SILs and AAR Summary Web Page

  • 6/8/2018 3:13:00 PM
  • View Count 2955
The DNR is proposing updates to PSD modeling guidance and is announcing the release of a new web page. Specifically, EPA’s recently released PM2.5 Significant Impact Levels (SILs) have been incorporated into the Prevention of Significant Deterioration (PSD) Modeling Guidelines, and a new web page has been added to assist applicants with filling out Form MD. The DNR is providing this information for a two-week informal comment period.
Revised Modeling Guidance Available for Use

Revised Modeling Guidance Available for Use

  • 6/8/2017 1:53:00 PM
  • View Count 3366
The DNR has updated various modeling guidance documents to incorporate the latest changes to federal modeling requirements.  The updates were reviewed with stakeholders at the May 25, 2017, AQ Client Contact meeting.  The guidance updates were also posted for a two week informal comment period that ended on June 7.  No comments were received so the documents were finalized as drafted.
Dispersion Modeling Data and Guidance Updates Available for Use

Dispersion Modeling Data and Guidance Updates Available for Use

  • 12/4/2015 9:28:00 AM
  • View Count 4179
The DNR has updated the pre-processed meteorological data for AERMOD, the default background concentrations, and various guidance documents. Projects with approved protocols that include approval to use the old data, and modeling analyses submitted prior to December 4, 2015, will not have to use the new data. Applicants submitting new projects on or after December 4 should begin using the updated data and guidance immediately. The updates are summarized below.