Skip to Content
Questions or Comments: siprules@tceq.texas.gov

Austin-Round Rock: Current Attainment Status

Compliance of Austin-Round Rock (ARR) area counties with the National Ambient Air Quality Standards (NAAQS).

Note: This table provides a list of designations and classifications for current, active NAAQS. While NAAQS that have been revoked by the EPA do not appear in this table, some anti-backsliding obligations may continue to apply for revoked standards. This table is to be used for informational purposes only and should not be used to determine regulatory requirements in any of the counties listed.

Austin–Round Rock Area: Attainment Status by Pollutant

 Pollutant

 Primary NAAQS

Averaging Period

 Designation

Counties

Attainment Deadline

 

Ozone (O3)*

 0.070 ppm (2015 standard)

8-hour 

Attainment/ Unclassifiable (Effective Jan 16, 2018) 

Travis, Williamson, Bastrop, Hays, Caldwell 

 

0.075 ppm
(2008 standard)

8-hour

Unclassifiable/ Attainment

Travis, Williamson, Bastrop, Hays, Caldwell

 

Lead (Pb)

0.15 µg/m3
(2008 standard)

Rolling 3-Month Average

Unclassifiable/ Attainment

 

 

Carbon Monoxide (CO)

9 ppm

8-hour

Unclassifiable/ Attainment

 

 

35 ppm

1-hour

Unclassifiable/ Attainment

 

 

Nitrogen Dioxide (NO2)

0.053 ppm

Annual

Unclassifiable/ Attainment

 

 

100 ppb

1-hour

Unclassifiable/ Attainment

 

 

Particulate Matter (PM10)

150 µg/m3

24-hour

Unclassifiable/ Attainment

 

 

Particulate Matter (PM2.5)

12.0 µg/m3 (2012 standard)

Annual (Arithmetic Mean)

Unclassifiable/ Attainment

 

 

15.0 µg/m3 (1997 standard)

Annual (Arithmetic Mean)

Unclassifiable/ Attainment

 

 

35 µg/m3

24-hour

Unclassifiable/ Attainment

 

 

Sulfur Dioxide (SO2)

0.03 ppm**

Annual (Arithmetic Mean)

Unclassifiable/ Attainment

 

 

0.14 ppm**

24-hour

Unclassifiable/ Attainment

 

 

75 ppb

1-hour

Attainment/
Unclassifiable

 

 

*The United States Environmental Protection Agency (EPA) revoked the one-hour ozone standard and the 1997 eight-hour ozone standard in all areas, although some areas have continuing obligations under these standards. See ozone history for more information.

**The standard is scheduled to be revoked one year after the effective date of final designations for the 75 ppb standard.

For more information on attainment status, visit the EPA's Green Book  webpage regarding nonattainment areas for criteria pollutants.

Austin–Round Rock Attainment Areas

2015 Eight-Hour Ozone Standard Designations: Attainment/Unclassifiable, effective January 16, 2018 ( 82 FR 54232 )
On October 1, 2015, the EPA lowered the primary and secondary eight-hour ozone NAAQS to 0.070 parts per million ( 80 FR 65292 ). Travis, Williamson, Bastrop, Hays, and Caldwell Counties were designated attainment/unclassifiable under the 2015 eight-hour ozone NAAQS, effective January 16, 2018. 

2008 Eight-Hour Ozone Standard Designations: Unclassifiable/Attainment, effective July 20, 2012 ( 77 FR 30088 )
On March 27, 2008, the EPA lowered the primary and secondary eight-hour ozone NAAQS to 0.075 parts per million (ppm) ( 73 FR 16436 ). Travis, Williamson, Bastrop, Hays, and Caldwell Counties were designated unclassifiable/attainment under the 2008 eight-hour ozone NAAQS, effective July 20, 2012.   

1997 Eight-Hour Ozone Standard Designations:  Attainment, April 30, 2004 ( 69 FR 23858 )  
Counties: Travis, Williamson, Bastrop, Hays, and Caldwell
On December 18, 2002, local governments in the ARR area entered into a voluntary Early Action Compact (EAC) agreement with the TCEQ and the EPA for the 1997 eight-hour ozone standard. On March 31, 2004, a final EAC plan was submitted to the TCEQ for incorporation into the State Implementation Plan. On November 17, 2004, the commission adopted the EAC attainment demonstrations for Austin, San Antonio, and Northeast Texas , and, at the request of the Austin and San Antonio areas, rule changes to 30 TAC 114 and 115.

National Ambient Air Quality Standards

The EPA has set National Ambient Air Quality Standards  (NAAQS) for six principal criteria pollutants: ground-level ozone, lead, carbon monoxide, nitrogen dioxide, sulfur dioxide, and particulate matter. 

No later than one year after promulgation of a new or revised NAAQS for any pollutant, the governor must submit designation recommendations to the EPA for all areas of the state. The EPA must then promulgate the designations within two years of promulgation of the revised NAAQS. Areas that do not meet (or contribute to ambient air quality in a nearby area that does not meet) the NAAQS are designated nonattainment. Areas that meet the NAAQS are designated attainment; and areas that cannot be classified based on the available information, unclassifiable.

For ozone, the federal Clean Air Act establishes nonattainment area classifications ranked according to the severity of the area’s air pollution problem. These classifications—marginal, moderate, serious, severe, and extreme—translate to varying requirements with which Texas and nonattainment areas must comply.