On December 18, 2014, EPA announced nonattainment designations for those areas that exceeded the 2012 annual PM2.5 standard and then revised the designations for some areas on March 31, 2015. Both rules became effective on April 15, 2015. State, tribal and local governments must prepare a plan which describes their efforts to reduce PM2.5. Transportation conformity requirements for the 2012 annual PM2.5 standard applied on April 15, 2016.
EPA published the “Fine Particulate Matter National Ambient Air Quality Standards: State Implementation Plan Requirements” final rule on August 24, 2016. The rule will be effective on October 24, 2016. In that rulemaking EPA finalized a revocation option that revokes the 1997 primary annual PM2.5 NAAQS in areas that have always been designated as attainment for the 1997 annual PM2.5 NAAQS and in areas that were designated as nonattainment areas but have been redesignated to attainment for that NAAQS (maintenance areas). These areas have been marked with a footnote on 2012 PM2.5 area maps. Additionally, under the finalized option EPA will continue to redesignate areas to attainment for the 1997 annual PM2.5 NAAQS, and the 1997 primary annual PM2.5 NAAQS will be revoked in those areas on the effective date of their redesignation.
On November 13, 2009, EPA announced nonattainment designations for those areas that exceeded the 2006 24-hour standards for PM2.5. These designations and classifications took effect on December 14, 2009. State, tribal and local governments must prepare a plan which describes their efforts to reduce PM2.5. Transportation conformity requirements for the 2006 24-hr PM2.5 standard applied on December 14, 2010.
On January 5, 2005 EPA announced nonattainment designations for those areas that exceeded the 1997 standards for PM2.5. These designations and classifications took effect on April 5, 2005. State, tribal and local governments must prepare a plan which describes their efforts to reduce PM2.5. Transportation conformity requirements for the PM2.5 standard applied on April 5, 2006.
On November 1, 2005, EPA proposed a rule to implement the PM2.5 standard. The proposal explains how EPA proposes to address attainment demonstrations and modeling, reasonably available control measures, reasonably available control technology, its policy on precursors, and new source review in PM2.5 nonattainment areas.
EPA rules and further information regarding PM2.5 designations and implementation is available on EPA's website.
On May 21, 2012, EPA announced nonattainment designations for those areas that exceeded the 2008 standards for ozone. These designations and classifications took effect on July 20, 2012. State, tribal and local governments must prepare a plan which describes their efforts to reduce ozone. Transportation conformity requirements for the 2008 ozone standard applied on July 20, 2013. On May 21, 2012 EPA issued a final rule that revoked the 1997 ozone standard for transportation conformity purposes effective one year after designations (July 20, 2013). However, this partial revocation was struck down in court and on March 6, 2015 EPA issued a final rule that revoked the 1997 ozone standard for all purposes. This rule became effective on April 6, 2015.
On April 15, 2004 EPA announced nonattainment designations for those areas that exceeded the 1997 standards for 8-hour ozone. These designations and classifications took effect for most areas on June 15, 2004. State, tribal and local governments must prepare a plan which describes their efforts to reduce ground-level ozone. Transportation conformity requirements for the 8-hour standard for most areas applied on June 15, 2005.
On April 30, 2004, EPA promulgated the first phase of the rule implementing the 8-hour ozone standard. Phase 1 of the implementation rule explains how EPA classified areas not meeting the national air quality standard for 8-hour ozone. It also established a process for transitioning from implementing the 1-hour standard for ozone to implementing the more protective 8-hour ozone standard. EPA revoked the 1-hour ozone standard effective June 15, 2005. The rule also established attainment dates for the 8-hour standard and the timing of emissions reductions needed for attainment.
On November 29, 2005, EPA promulgated the second phase of the implementation rule. Phase 2 of the implementation rule explains how attainment demonstrations and modeling, reasonable further progress, reasonably available control measures, reasonably available control technology, new source review, and reformulated gasoline must be addressed in 8-hour ozone nonattainment areas.
Several Early Action Compact (EAC) areas are designated as "nonattainment" for the 8-hour standard. EACs are agreements signed by representatives of local communities, State and Tribal air quality officials, and EPA Regional Administrators that provide for control of emissions under the 8-hour standard earlier than the Clean Air Act would otherwise require. However, as long as EAC areas meet agreed upon milestones, the impact of nonattainment designations for the 8-hour ozone standard will be deferred, which means that certain Clean Air Act requirements, such as transportation conformity, will not apply. For more information regarding EACs, please see EPA's website.
EPA rules and further information regarding 8-hour ozone designations and implementation is available on EPA's website
