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Northeast Texas: Ozone History

Background and history of Northeast Texas (NETX) area compliance with the National Ambient Air Quality Standards (NAAQS) for ground-level ozone.

2008 Eight-Hour Ozone Standard (2008 to Present)

On March 27, 2008, the U.S. Environmental Protection Agency (EPA) strengthened the primary and secondary eight-hour ozone standard to 0.075 parts per million (73 FR 16436 Exit the TCEQ). On March 10, 2009, the governor recommended to the EPA that Gregg, Rusk, and Smith counties be designated nonattainment for the 2008 ozone standard (see the governor's letter to EPA region 6).

In September 2009, the EPA announced it would reconsider the 2008 NAAQS, and on January 19, 2010, proposed to lower the primary ozone standard to a range of 0.060–0.070 ppm, and proposed a separate secondary standard based on cumulative seasonal average ozone concentrations. On September 2, 2011, President Obama announced that he had requested the EPA withdraw the proposed reconsidered ozone NAAQS.

In a memo dated September 22, 2011, from EPA Assistant Administrator Gina McCarthy, the EPA announced that it would proceed with initial area designations under the 2008 eight-hour ozone standard, starting with the recommendations states made in 2009 and updating them with the most current, certified air quality data (2008 through 2010).

On May 21, 2012, the EPA published in the Federal Register final designations for the 2008 eight-hour ozone standard (77 FR 30088 Exit the TCEQ). Gregg, Harrison, Rusk, Smith, and Upshur Counties were designated attainment/unclassifiable under the 2008 eight-hour ozone NAAQS, effective July 20, 2012.  

1997 Eight-Hour Ozone Standard (1997 to 2015)

Note: Effective April 6, 2015, the 1997 eight-hour ozone standard has been revoked in all areas, although some former 1997 eight-hour ozone nonattainment areas have continuing obligations to comply with the anti-backsliding requirements described in 40 CFR §51.1100(o).

In July 1997, the EPA announced a new NAAQS for ground-level ozone. The EPA phased out and replaced the previous one-hour standard with an eight-hour standard to protect public health against longer exposure to this air pollutant. The EPA set the new eight-hour ozone standard at 0.08 ppm, which became effective on June 15, 2004. 

On December 20, 2002, the TCEQ and local organizations signed an Early Action Compact (EAC) for the NETX area. On November 17, 2004, the commission adopted revisions to the SIP for the Austin, San Antonio, and NETX EAC areas and to 30 TAC 114 Exit the TCEQ and 115 Exit the TCEQ. The adopted revision to the NETX SIP consisted of a local plan submitted to the TCEQ by the area in March 2004, under its EAC. This revision contained results of photochemical modeling and technical documentation to support that the area would attain the 1997 eight-hour ozone standard by 2007. The EPA approved the NETX plan on August 19, 2005.

The EAC program concluded in the spring of 2008.

One-Hour Ozone Standard

Note: In 1997, the one-hour ozone standard was replaced by the more protective eight-hour ozone standard. The one-hour standard has been revoked in all areas, although some former one-hour ozone nonattainment areas have continuing obligations to comply with the anti-backsliding requirements described in 40 CFR 51.905(a).

In 1996, local officials, local industry representatives, the TCEQ, and the EPA established the Flexible Attainment Region (FAR) Agreement for the Northeast Texas area, after the one-hour ozone standard was violated in Gregg County. As part of the FAR, several companies in the Northeast Texas region agreed to voluntarily reduce NOx emissions. On May 12, 1999, the commission adopted a Northeast Texas FAR SIP revision.

A SIP revision for the Northeast Texas region was adopted March 13, 2002, replacing the expired FAR Agreement.

Comprehensive History of the Texas SIP

This SIP History gives a broad overview of the SIP revisions that have been submitted to the EPA by the State of Texas. Some sections may be obsolete or superseded by new revisions, but have been retained for the sake of historical completeness.