EDF Tracks Air Quality in Areas Removed from the Texas Air Pollutant Watch List

EDF’s Maia Draper co-wrote this post

We’ve written before about the Air Pollutant Watch List, a Texas program for addressing harmful air pollutants that pose a particularly high risk to public health.

The Texas Commission on Environmental Quality (TCEQ) adds areas to the Air Pollution Watch List where monitoring data show persistently high concentrations of air toxics above the state’s health-based guidelines for these substances.

Listing an area on the Air Pollution Watch List enables TCEQ to dedicate additional time and resources to reducing air toxic emissions in these areas. A listing can serve as an important tool for reducing dangerous air pollution and protecting public health.

However, since 2007, TCEQ has removed 14 monitored pollutants in 10 areas from the Air Pollution Watch List. TCEQ says that average concentration levels of air toxics in these areas no longer exceed state guidelines, and therefore that additional scrutiny and resources to encourage air quality improvements are no longer necessary.

TCEQ’s Air Pollution Watch List delisting decisions can be controversial, in part due to questions about whether air monitoring data are sufficient to support the delisting decision, and to what extent the Air Pollution Watch List label is still needed as a tool to deter high long-term emissions of harmful pollutants or short-term emissions spikes that can pose an immediate danger to public health.

To find out whether air quality improvements have persisted in areas that have been removed from the Air Pollution Watch List, EDF conducted a comprehensive analysis of air monitoring data for all Air Pollution Watch List areas delisted since the program’s inception.

Our analysis reveals several shortcomings in the way that TCEQ currently collects and reports these data, and recommends several crucial steps that TCEQ should take to better monitor emissions and protect public health in areas that have been removed from the Air Pollution Watch List.

Areas among 16 TCEQ regions that have been removed from the APWL. Source: TCEQ Air Monitoring Site Data. Map created using ArcGIS.

Among them:

• Address short-term emissions spikes in delisted areas

For some areas that have been delisted, we found continuing exceedances of TCEQ’s recommended concentration levels for air toxics, suggesting that these areas have not adequately maintained the air quality improvements that led to their removal from the Air Pollution Watch List. In particular, while average annual concentration levels of air toxics for most areas are below TCEQ’s health-based threshold, there is wide variability in these levels throughout the year, indicating that short-term spikes in concentrations of harmful air pollutants continue to be a problem in these delisted areas, posing a potential threat to public health. TCEQ should take steps to address these short-term spikes.

• Improve transparency of the Air Pollution Watch List program 

Our analysis also revealed problems with data transparency – air monitoring data for nine monitors located in the delisted Air Pollution Watch List areas analyzed in this report are not currently available to the public. We also recommend that TCEQ improve transparency about the investigative and enforcement actions it takes in response to violation of health-based pollution levels. Improving the transparency of all aspects of the Air Pollution Watch List program, including areas that have been removed from the list but still require ongoing monitoring, is a fundamental step needed to improve its effectiveness.

• Improve accuracy of data collection and presentation to the public 

Our analysis also finds inconsistencies in TCEQ’s data collection and presentation protocols for hazardous air pollutants that undermine the accuracy of its air quality monitoring and data analysis. We propose ways for TCEQ to improve the precision and usefulness of its air quality monitoring data, in order to provide the public with a more accurate and complete assessment of air quality levels. In order to better protect public health, TCEQ should improve the precision and granularity of the data it uses as the basis for Air Pollution Watch List listing and delisting decisions.

Reducing emissions of air toxics is an important public health goal. Both short-term and long-term exposure to these emissions can cause severe adverse health effects, including respiratory distress, problems with the central nervous system, and cancer. At high levels, exposure to these toxics can even result in death.

The Texas Air Pollution Watch List system plays an important role in limiting human exposure to these dangerous compounds, which is why it is important for TCEQ to use rigorous and transparent data analysis before it decides to delist an area, and for it to continue to monitor these areas after delisting to safeguard against continued emissions of hazardous air pollutants in these areas.

You can read our full analysis here.