Air Quality Status of Central Texas
Is the Texas capital area in compliance with national air quality standards? Explore the current state of the region's air with a look at monitoring data and more.
National Ambient Air Quality Standards Attainment Status
As of 2012, all parts of the CAPCOG region are both designated attainment and measuring attainment for all National Ambient Air Quality Standards (NAAQS). EPA uses air quality monitors operated by the Texas Commission on Environmental Quality (TCEQ) to determine if a region is in attainment of the NAAQS or not.
Although EPA has not posted the official design values for all pollutants for 2013, the data as reported on TCEQ’s website for the region indicates that it will continue to be in attainment of all NAAQS for 2013 as well. The table below shows all of the NAAQS that are currently in effect for the six “criteria” pollutants, along with the "design value" for the region (the statistic that EPA uses to determine compliance):
- Carbon Monoxide (CO);
- Lead (Pb);
- Nitrogen Dioxide (NO2);
- Ozone (O3);
- Sulfur Dioxide (SO2); and
- Particulate Matter (PM)
- PM10 for sizes 10 microns and less
- PM2.5 for sizes 2.5 microns and less
Standards are expressed in terms of parts per million (ppm), parts per billion (ppb), or micrograms per cubic meter (µg/m3)
|CAPCOG Region Criteria Pollutant Design Values Compared to NAAQS|
|Standard||NAAQS||2012 Design Value||Site|
|CO 8 Hours||9 ppm||0.3 ppm||CAMS 0003|
|CO 1 Hour||35 ppm||0.7 ppm||CAMS 0003|
|Pb 3 Month Avg.||0.15 µg/m3||unmonitored||unmonitored|
|NO2 1-Hour||100 ppb||< 3 years of data||< 3 years of data|
|NO2 Annual Avg.||53 ppb||< 3 years of data||< 3 years of data|
|O3 8-Hours||0.075 ppm||0.074 ppm||CAMS 0003|
|PM2.5 Annual Avg.||12 µg/m3||10.2 µg/m3||CAMS 0171|
|PM2.5 24 Hours||35 µg/m3||21 µg/m3||CAMS 0171|
|PM10 24 Hours||150 µg/m3||30 µg/m3||CAMS 0171|
|SO2 1 Hour||75 ppb||unmonitored||unmonitored|
|SO2 3 Hours||0.5 ppm||unmonitored||unmonitored|
The figure below summarizes the region’s 2012 design values as a percentage of the current standard.
Trends in Ozone Design Value
While the region is currently in attainment of all NAAQS, its ozone levels sometimes reach levels currently considered unhealthy by the U.S. Environmental Protection Agency, and the region’s design value for 2012 is 99 percent of the ozone NAAQS.
If the data reported on TCEQ’s website for 2013 are certified, it will drop to 97 pecent of the NAAQS, and the region’s controlling monitor will shift from CAMS 3 (Murchison Middle School) to CAMS 38 (Austin Audubon Society).
Since 1999, the region’s ozone design value has steadily declined, although reductions in the design value have slowed in recent years. Over this entire period, design values have decreased, on average, by 1.27 parts per billion per year.
Since the Clean Air Coalition initiated its first voluntary air quality plan in 2002 – the 1-Hour Ozone Flex Plan – the Austin-Round Rock MSA has had the steepest drop in ozone levels of any near-nonattainment area in the state in terms of both absolute reduction and percent reduction. The only area of the state with a larger absolute or percent reduction was the Houston-Galveston-Brazoria nonattainment area.
TCEQ Toxicological Evaluation of 2012 Ambient Monitoring Data
Each year, TCEQ’s Toxicology Division evaluates ambient air sampling conducted in CAPCOG’s 10-county area, Region 11, focusing on exposure to volatile organic compounds and metals to determine whether the population was being exposed to any potentially unhealthful levels of these substances. The most recent evaluation was of the 2012 sampling and was completed on July 11, 2013. The main findings:
“The 2012 annual average concentrations for all VOCs were well below their respective long-term AMCVs [Air Monitoring Comparison Values]. Therefore, adverse health effects would not be expected to occur as a result of long-term exposure to the reported levels of these chemicals at the Austin Webberville Road monitoring site;” and
“The 2012 annual average concentrations for all metals (PM2.5) were well below their respective AMCVs. Therefore, adverse health effects would not be expected to occur as a result of long-term exposure to the reported health levels of these chemicals at the Austin Audubon Society monitoring site.”