General Conformity Regulatory Actions
This page contains a chronological listing of regulatory actions and correspondence related to the General Conformity revisions from March 2006 to March 2010.
- Final rule. PM2.5 NAAQS: SIP Requirements Rule
August 24, 2016 - EPA revised the tables at 40 CFR 93.153(b)(1) and (b)(2), which contain the de minimis threshold rates applicable to General Conformity, to remove the phrase, "(if determined to be a significant precursor)," that applied, prior to the revision, to VOC and ammonia emissions as PM2.5 precursor emissions. The final rule stated the principal precursor gases of PM2.5 emissions are SO2, NOx, VOC, and ammonia (NH3) and that these gases are precursors to secondary PM2.5 formation. (81 FR 58010, 58014, 58015; 8/24/2016). The EPA added that, prior to this final rule, the definition of PM2.5 precursors under General Conformity section 93.152, did not reflect the rebuttable presumptions for VOC and ammonia as precursors of the secondary formation of PM2.5 emissions. (81 FR 58010, 580126; 8/24/2016). However, the final rule made no correction to the definition of PM2.5.
- Final revisions to the General Conformity Regulations
March 24, 2010 - EPA revised the General Conformity regulations. The revised rule improves the process federal entities use to demonstrate that their actions will not contribute to a violation of a national air quality standard.
Learn more about the March 2010 action.
- EPA proposes revisions to the General Conformity Regulations
December 20, 2007 - These requirements would update and streamline the conformity determination process. EPA recognizes that NOx, SO2, VOC, and ammonia (NH3) as precursors of the secondary formation of PM2.5 emissions. (72 FR 20586, 20589; 4/25/2007).
Learn more about the December 2017 action.
- Final Fine Particle Pollution De Minimis Emission Levels for General Conformity Applicability
July 11, 2006 - EPA established "de minimis" emission levels for fine particle pollution. These emissions thresholds will be used to determine whether requirements would apply under EPA's General Conformity regulations. You may want to view a listing of de minimis emission levels for each criteria pollutant.
Learn more about the July 2006 action.
- EPA Withdraws Fine Particle Exemption for Agencies, Cites Adverse Comments
June 1, 2006 - The Environmental Protection Agency withdrew a direct final rule that had exempted the federal government from general conformity requirements for actions that result in fine particle emissions of 100 tons a year or less, citing adverse public comments.
Learn more about the June 2006 action.
- Direct Final Fine Particle Pollution De Minimis Emission Levels for General Conformity Applicability
March 31, 2006 - EPA established "de minimis" emission levels for fine particle pollution. These emissions thresholds will be used to determine whether requirements would apply under EPA's General Conformity rules.