EPA has designated nonattainment areas for the 1997 8-hour ozone and PM2.5 air quality standards. Transportation conformity requirements applied to the 8-hour ozone and PM2.5 nonattainment areas one year after the effective date of their designation by EPA.
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. 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 implmentation 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 here on EPA's website.
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 here on EPA's website.