EPA is providing an important opportunity for interested stakeholders to review the draft guidance and supporting documents recommending Significant Impact levels (SILs) for ozone and fine particle pollution that may be used in the Prevention of Significant Deterioration (PSD) permitting program. SILs have been used in the PSD permitting process for many years to help determine whether proposed construction may be authorized in a Clean Air Act permit. EPA will accept public comment on the draft guidance and supporting documents through September 30, 2016.
You will need Adobe Reader to view some of the files on this page. See EPA’s About PDF page to learn more.- Legal Support Memorandum Application of Significant Impact Levels in the Air Quality Demonstration for Prevention of Significant Deterioration Permitting under the Clean Air Act for Public Review (PDF)(10 pp, 82 K, August 1, 2016)
- Technical Basis for the EPA's Development of Significant Impact Levels for PM2.5 and Ozone, Appendices (PDF)(200 pp, 24 MB, August 1, 2016)
- Draft Guidance on Significant Impact Levels for Ozone and Fine Particles in the Prevention of Significant Deterioration Permitting Program (PDF)(14 pp, 422 K, August 18, 2016)
- Technical Basis for the EPA’s Development of Significant Impact Thresholds for PM2.5 and Ozone (PDF)(52 pp, 2 MB, August 1, 2016)