Air Pollution from Ozone
- What is ozone?
- Latest air quality planning that addresses the ozone NAAQS
- Related Web pages and publications
- Get more information on the Texas SIP and contact the TCEQ
What is ozone?
What is ozone? How is it formed? Why should we be concerned about this air pollutant?
Latest air quality planning that addresses the ozone NAAQS
Last updated: 7/2/2014
Emissions Inventory (EI) SIP Revision for the 2008 Eight-Hour Ozone Standard for the Houston-Galveston-Brazoria (HGB) and Dallas-Fort Worth (DFW) Areas
On July 2, 2014, the commission adopted the EI SIP revision for the 2008 Eight-Hour Ozone Standard (Non-Rule Project No. 2013-016-SIP-NR). This SIP revision satisfies the Federal Clean Air Act (FCAA), §172 and §182 requirements for the HGB and DFW nonattainment areas under the 2008 eight-hour ozone standard. The SIP revision includes 2011 emissions inventories for ozone precursors (volatile organic compounds and nitrogen oxides) from point, area, on-road mobile, non-road mobile, and biogenic emissions source categories as the base year emissions inventories for the HGB and DFW areas. The nonattainment area base year EI submission is due no later than 24 months from the July 20, 2012 effective date of designations under the 2008 eight-hour ozone standard, July 20, 2014.
- Adopted SIP Revision
- Appendix A: Characterization of Oil and Gas Production Equipment and Develop a Methodology to Estimate Statewide Emissions
- Appendix B: Condensate Tank Oil and Gas Activities
- Appendix C: Development of 2008 Annual and Ozone Season Daily Emissions Inventories and Activity Data for Non-road Sources within the Texas NONROAD Model (TexN)
- Appendix D: Development of Statewide Annual Emissions Inventory and Activity Data for Airports
- Appendix E: Development of Annual Emissions Inventories and Activity Data for Airports in the 12-County Dallas-Fort Worth Area
- Appendix F: Development of 2011 Statewide Toxics and Actual Annual and Ozone Season Weekday Emissions Inventories for Commercial Marine Vessels
- Appendix G: Development of Texas Statewide Drilling Rigs Emissions Inventories for the Years 1990, 1993, 1996, and 1999 through 2040
- Appendix H: 2011 Texas Railroad Emission Inventory Report
- Appendix I: Development of 2011 On-road Mobile Source Actual Annual and Summer Weekday Emissions Inventories for All Texas Counties (Except for 12 Counties in the Dallas-Fort Worth Area), and Winter Weekday Emissions Inventories for El Paso: Houston-Galveston-Brazoria Area
- Appendix J: Development of 2011 On-road Mobile Source Actual Annual and Summer Season Weekday Emissions Inventories for 12 Counties in the Dallas-Fort Worth Metropolitan Statistical Area-Amendment
- Appendix K: Point Source HGB and DFW Site Level Emissions
Infrastructure and Transport SIP Revision for the 2008 Ozone Standard
On December 5, 2012, the commission adopted the Federal Clean Air Act (FCAA), §110(a)(1) and (2) Infrastructure and Transport SIP Revision for the 2008 Ozone NAAQS (Non-Rule Project No. 2012-004-SIP-NR). This SIP revision outlines the requirements of FCAA, §110(a)(2)(A) through (M) and the Texas provisions supporting the requirements. These requirements include basic program elements such as enforceable emission limitations and control measures, air quality monitoring and modeling, a permitting program, adequate funding and personnel, authority under state law to carry out the plan, emissions reporting, emergency powers, public participation, and fee collection. This SIP revision also includes a technical demonstration to support that Texas meets the interstate transport requirements of FCAA, §110(a)(2)(D)(i)(I).
A public hearing was held on September 25, 2012 at the Texas Commission on Environmental Quality headquarters in Austin. The public comment period was from August 24 through September 28, 2012. Comments were submitted by the United States Environmental Protection Agency, Alamo Area Council of Governments, Public Citizen, and four individuals.
Proposed Ozone Standard Revision
On November 25, 2014, the EPA proposed to lower the primary NAAQS for ozone from an eight-hour standard at 0.075 ppm to an eight-hour standard from 0.070 ppm to 0.065 ppm (79 FR 75234) . The EPA is also taking comment on lowering the standard to 0.060 ppm as well as retaining the current standard of 0.075 ppm. The EPA also proposed to set a secondary NAAQS for ozone within the range of 0.070 ppm to 0.065 ppm to protect public welfare. The EPA is also seeking comment on setting the standard based on the weighted (W126) metric within a range of 13 to 17 ppm-hours, averaged over three years and on defining a target protection level in terms of a W126 index value as low as 7 to 13 ppm-hours. In addition, the EPA is taking comment on retaining the existing eight-hour secondary standard of 0.075 ppm. The standard is scheduled to be finalized by October 1, 2015.
The 2008 Ozone Standard
On March 27, 2008, the EPA lowered the primary and secondary eight-hour ozone NAAQS to 0.075 parts per million (73 FR 16436) . On May 21, 2012, the EPA published in the Federal Register final designations for the 2008 eight-hour ozone standard (77 FR 30088) . The Dallas-Fort Worth (DFW) area was designated moderate nonattainment and the Houston-Galveston-Brazoria (HGB) area was designated marginal nonattainment. The effective date of the final rule is July 20, 2012.
On May 21, 2012, the EPA also published in the Federal Register a final rule to establish classification thresholds, establish December 31 of each relevant calendar year as the attainment date for each classification, and revoke the 1997 eight-hour ozone NAAQS for purposes of transportation conformity (77 FR 30160) .
For more information on the ozone standard, see:
For more information on the TCEQ's designation recommendation process, see: