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 While NAAQS that have been revoked by the EPA do not appear in this table, some anti-backsliding obligations may continue to apply for revoked standards.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 |
8-hour |
Unclassifiable/ Attainment |
Travis, Williamson, Bastrop, Hays, Caldwell |
|
|
Lead (Pb) |
0.15 µg/m3 |
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/ |
|
|
*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
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.