An official website of the United States government.

We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Ground-level Ozone Pollution

Maximum Clean Air Act (CAA) Timeframe Associated With Each SIP Element (From Effective Date of Designation)

Note: these timeframes apply to the 2008 and 2015 National Ambient Air Quality Standards (NAAQS) for ozone, as noted.

Emission inventories and emission statement SIPs

For states with Marginal and higher areas:

  • due no later than 2 years
    • 2008 ozone NAAQS - July 20, 2014
    • 2015 ozone NAAQS - August 3, 2020 (Sep. 24, 2020 for San Antonio)

Reasonably Available Control Technology (RACT) SIPs

For Moderate and higher areas, and all states in the Ozone Transport Region (OTR):

  • no later than 2 years
    • 2008 ozone NAAQS - July 20, 2014
    • 2015 ozone NAAQS - August 3, 2020

Reasonable Further Progress (RFP) SIPs

For Moderate areas (showing 15% RFP over 6-year rate-of-progress/RFP period):

  • no later than 3 years
    • 2008 ozone NAAQS - July 20, 2015
    • 2015 ozone NAAQS - August 3, 2021

For Serious and higher areas (showing avg. 3% per year RFP for initial 6-year period and all remaining 3-year periods):

  • no later than 4 years
    • 2008 ozone NAAQS - July 20, 2016
    • 2015 ozone NAAQS - August 3, 2022

Nonattainment NSR (NNSR) SIPs

  • no later than 3 years
    • 2008 ozone NAAQS - July 20, 2015
    • 2015 ozone NAAQS - August 3, 2021 (Sep. 24, 2021 for San Antonio)

Attainment plan with Reasonably Available Control Measures (RACM), and attainment demonstration SIPs

For Moderate areas:

  • no later than 3 years 
    • 2008 ozone NAAQS - July 20, 2015
    • 2015 ozone NAAQS - August 3, 2021

For Serious and higher:

  • 4 years 
    • 2008 ozone NAAQS - July 20, 2016
    • 2015 ozone NAAQS - August 3, 2022

Vehicle I/M program SIP

Where applicable:

  • no later than an area’s attainment demonstration deadline

Stationary source penalty fee program SIPs (§185)

For Severe and Extreme areas:

  • no later than 10 years
    • 2008 ozone NAAQS - July 20, 2022
    • 2015 ozone NAAQS - August 3, 2028