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Air Pollution from Ozone

General information on ozone, and TCEQ planning that addresses the ozone National Ambient Air Quality Standards (NAAQS).

The SIP files on this page are hosted by the Texas Records and Information Locator (TRAIL) web archive . If you need assistance with a file, please contact siprules@tceq.texas.gov.

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: 11/16/2022

New El Paso County Emissions Inventory (EI) SIP Revision for the 2015 Eight-Hour Ozone NAAQS

On November 16, 2022, the commission adopted the 2015 Eight-Hour Ozone NAAQS EI SIP Revision for the El Paso County portion of the El Paso-Las Cruces, Texas-New Mexico Nonattainment Area. The SIP revision satisfies the federal Clean Air Act, §172(c)(3) and §182(a)(1) EI reporting requirements for El Paso County for the 2015 eight-hour ozone NAAQS. The SIP revision also includes a certification statement to confirm that the emissions statements and nonattainment new source review requirements have been met for El Paso County.

Proposed El Paso County Emissions Inventory (EI) SIP Revision for the 2015 Eight-Hour Ozone NAAQS

On June 15, 2022, the commission approved proposal of the 2015 Eight-Hour Ozone NAAQS EI SIP Revision for the El Paso County portion of the El Paso-Las Cruces, Texas-New Mexico Nonattainment Area. The proposed SIP revision would satisfy the federal Clean Air Act, §172(c)(3) and §182(a)(1) EI reporting requirements for El Paso County for the 2015 eight-hour ozone NAAQS. The proposed SIP revision would also include a certification statement to confirm that the emissions statements and nonattainment new source review requirements have been met for El Paso County.

The public comment period will open on June 17, 2022 and close on July 21, 2022. A public hearing on the proposed SIP revision will be held on July 18, 2022 at 6:00 p.m. MDT in the Carlos M. Ramirez TecH2O Water Resources Learning Center, located at 10751 Montana Avenue in El Paso, Texas. The hearing will be conducted in English, and Spanish language interpretation services will be made available. For more information, please visit the Proposed SIP Revisions and Public Hearing Information section of the Texas SIP Revisions webpage.

2015 Eight-Hour Ozone NAAQS EI SIP Revision for the Houston-Galveston-Brazoria (HGB), Dallas-Fort Worth (DFW), and Bexar County Nonattainment Areas

On June 10, 2020, the commission adopted the 2015 Eight-Hour Ozone NAAQS EI SIP Revision for the HGB, DFW, and Bexar County Nonattainment Areas (Non-Rule Project No. 2019-111-SIP-NR). The SIP revision satisfies federal Clean Air Act (FCAA), §172(c)(3) and §182(a)(1) EI reporting requirements for areas designated nonattainment for the 2015 eight-hour ozone NAAQS. The revision also includes certification statements to confirm that the emissions statement and nonattainment new source review requirements have been met for the HGB, DFW, and Bexar County 2015 eight-hour ozone nonattainment areas.

Proposed 2015 Eight-Hour Ozone NAAQS EI SIP Revision for the HGB, DFW, and Bexar County Nonattainment Areas

On November 20, 2019, the commission approved proposal of the 2015 Eight-Hour Ozone NAAQS EI SIP Revision for the HGB, DFW, and Bexar County Nonattainment Areas (Non-Rule Project No. 2019-111-SIP-NR). The proposed SIP revision would satisfy FCAA, §172(c)(3) and §182(a)(1) EI reporting requirements for areas designated nonattainment for the 2015 eight-hour ozone NAAQS. The revision would also include a certification statement to confirm that the emissions statements and nonattainment new source review requirements have been met for the HGB, DFW, and Bexar County 2015 eight-hour ozone nonattainment areas.

The public comment period opened on November 22, 2019 and closed on January 10, 2020. Public hearings on the proposed SIP revision were held at the following times and locations:

  • January 7, 2020 at 2:00 p.m. at the Arlington City Hall Council Chambers, 101 W. Abram Street, Arlington, Texas
  • January 8, 2020 at 2:00 p.m. at the Texas Department of Transportation District Office, Room 106, 7600 Washington Avenue, Houston, Texas
  • January 9, 2020 at 2:00 p.m. at the TCEQ Region 13 Office, 14250 Judson Road, San Antonio, Texas

For additional public hearing information, please visit the Texas SIP Revisions webpage.

Infrastructure and Transport SIP Revisions for the 2015 Ozone Standard

On August 8, 2018, the commission adopted two revisions to the Texas SIP for the 2015 ozone NAAQS: the 2015 Ozone NAAQS Infrastructure SIP Revision (Non-Rule Project No. 2017-040-SIP-NR) and the 2015 Ozone NAAQS Transport SIP Revision (Non-Rule Project No. 2017-039-SIP-NR). Infrastructure and Transport SIP revisions for the 2015 ozone NAAQS were due to the United States Environmental Protection Agency (EPA) by October 1, 2018.

Proposed Infrastructure and Transport SIP Revisions for the 2015 Ozone Standard

On March 7, 2018, the commission approved proposal of two revisions to the Texas SIP for the 2015 ozone NAAQS: the 2015 Ozone NAAQS Infrastructure SIP Revision (Non-Rule Project No. 2017-040-SIP-NR) and the 2015 Ozone NAAQS Transport SIP Revision (Non-Rule Project No. 2017-039-SIP-NR). Infrastructure and Transport SIP revisions for the 2015 ozone NAAQS are due to the United States Environmental Protection Agency (EPA) by October 1, 2018. A public hearing for both SIP revisions was held at 2:00 p.m. on April 10, 2018 at the Texas Commission on Environmental Quality, 12100 Park 35 Circle, Building E, Room 201S.

The proposed 2015 Ozone NAAQS Infrastructure SIP revision would outline the requirements of FCAA, §110(a)(2)(A) through (C) and (E) 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.

The proposed 2015 Ozone NAAQS Transport SIP revision would document how the transport elements listed in FCAA, §110(a)(2)(D) are currently addressed in the Texas SIP. This SIP revision would provide a detailed technical demonstration and other supporting information to meet the interstate transport requirements of FCAA, §110(a)(2)(D)(i) and (ii).

The 2015 Ozone NAAQS

On October 1, 2015, the EPA revised the primary and secondary NAAQS for ozone to an eight-hour standard of 0.070 parts per million (ppm), or 70 parts per billion (ppb) ( 80 FR 65292 ). The 2015 eight-hour ozone NAAQS became effective on December 28, 2015. The EPA designated six Houston-Galveston-Brazoria (HGB) area counties (Brazoria, Chambers, Fort Bed, Galveston, Harris, and Montgomery) and nine Dallas-Fort Worth (DFW) area counties (Collin, Dallas, Denton, Ellis, Johnson, Kaufman, Parker, Tarrant, and Wise) as nonattainment for the 2015 eight-hour ozone NAAQS, effective August 3, 2018 ( 83 FR 25766 ). The EPA designated Bexar County as nonattainment for the 2015 eight-hour ozone NAAQS, effective September 24, 2018 ( 83 FR 35136 ). Each of the three nonattainment areas in Texas were assigned a marginal classification. Under the marginal classification, the DFW and HGB areas are required to meet the 2015 eight-hour ozone NAAQS by the end of 2020 to meet an attainment date of August 3, 2021, while Bexar County must meet an attainment date of September 24, 2021. 

For more information on the 2015 ozone standard, see:

For more information on Texas' state designation recommendations for the 2015 ozone NAAQS, see:

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 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 was 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.

Infrastructure and Transport SIP Revision for the 2008 Ozone Standard

On December 5, 2012, the commission adopted the 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. 

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, effective July 20, 2012 ( 77 FR 30088 ). The Dallas-Fort Worth (DFW) area (Collin, Dallas, Denton, Ellis, Johnson, Kaufman, Parker, Rockwall, Tarrant, and Wise Counties) was designated moderate nonattainment and the Houston-Galveston-Brazoria (HGB) area (Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller Counties) was designated marginal nonattainment.

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 ). On March 6, 2015, the EPA published a final SIP requirements rule for implementing the 2008 eight-hour ozone NAAQS ( 80 FR 12264 ). On February 16, 2018, the United States Court of Appeals for the District of Columbia Circuit issued an opinion in the case South Coast Air Quality Management District vs. EPA, 882 F.3d 1138 (D.C. Cir. 2018) . The court’s decision vacated parts of the EPA’s final 2008 eight-hour ozone standard SIP requirements rule, including the redesignation substitute, removal of anti-backsliding requirements for areas designated nonattainment under the 1997 eight-hour ozone NAAQS, waiving requirements for transportation conformity for maintenance areas under the 1997 eight-hour ozone NAAQS, and elimination of the requirement to submit a second 10-year maintenance plan.

The HGB area was reclassified from marginal to moderate nonattainment on December 14, 2016 ( 81 FR 90207 ). On August 23, 2019, the EPA reclassified the DFW and HGB areas from moderate to serious nonattainment for the 2008 eight-hour ozone NAAQS ( 84 FR 44238 ). The attainment date for serious nonattainment areas is July 20, 2021 with a 2020 attainment year.

For more information on the TCEQ's designation recommendation process for the 2008 ozone NAAQS, see:

Related webpages and publications

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