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Ozone (O3) Implementation

Information provided for informational purposes onlyNote: EPA no longer updates this information, but it may be useful as a reference or resource. See the latest information at the Ozone Implementation web site
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This web site contains a variety of information related to several aspects of the ozone National Ambient Air Quality Standard (NAAQS) attainment effort. The site is intended to make easily available information on both data and policy related to the ozone NAAQS.

One topic covered is the regional transport of ozone (RTO) and ozone precursors (including nitrogen oxides or NOx). Certain States were required to revise their State implementation plan (SIP) measures under EPA's NOx SIP call to ensure that emissions reductions are achieved to mitigate the regional transport of ozone across State boundaries in the eastern half of the United States. Federal implementation plans (FIPs) may be needed to reduce regional transport if any State fails to adequately revise its SIP to comply with the NOx SIP call.

Section 126 of the Clean Air Act is another aspect of ozone transport. In accordance with section 126, numerous States filed petitions requesting EPA to make findings and require decreases in NOx emissions from certain stationary sources in upwind States that may significantly contribute to ozone nonattainment problems in the petitioning State.

Historical information is given on the Ozone Transport Assessment Group (OTAG) which was a partnership between the EPA, the Environmental Council of the States and various industry and environmental groups which assessed the long-range transport of ozone and ozone precursors.

Data on current designated nonattainment areas are contained the "Green Book" which is available here. Links to technical resources related to the ozone program are also available. They contain copies of various policy memoranda and reports on VOC and NOx control.

Additionally, this site contains information related to EPA effort to develop an implementation rule for the 1997 8-hour National Ambient Air Quality Standard. Issue papers and presentations for three national public meetings are presented. These deal with topics such as area classifications, attainment dated, mandatory controls, progress requirements, transport of ozone, and attainment demonstration requirements.

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