TCEQ warning system has failed to indicate widespread extent of some episodes

People in the Houston region have been exposed to more days with high ozone levels in 2005 than in any first six month period in at least nine years. As of June 29, the eight-hour ozone standard has been exceeded on 28 days.

The Texas Commission on Environmental Quality website provides data on exceedances of the eight-hour ozone standard back through 1997. During those eight years, ozone air pollution levels have exceeded the new eight-hour average standard level between 9 and 21 days during January through June (average of 17 days). By this measure, air pollution exposure is 50% worse this year than in recent history.

(In addition, the older one-hour standard has been violated on 2 additional days in 2005. EPA repealed this standard earlier this month. The repeal of this standard leaves the Houston region with less protection from high peaks of ozone air pollution which are often caused by industrial releases.)

TCEQ warning system has failed to indicate widespread extent of some episodes 
The current Texas Commission on Environmental Quality ozone air pollution warning system provides inadequate information in certain conditions. The warnings are systematically underestimating the extent of air pollution episodes under certain conditions. The TCEQ should revise its ozone warning system to incorporate ideas recommended last year by regional stakeholders or adopt other changes to address the problem.

Last year, the TCEQ collaborated with the Regional Air Quality Planning Committee to adopt a revised method for warning the public about high ozone levels. In order to address health concerns raised by the eight-hour standard, a predictive system was needed to provide warnings before the eight-hour standard was officially exceeded. Although such a system cannot provide perfect predictions, it can and must perform better than the system currently used by the TCEQ.

Advised by regional stakeholders, the Houston-Galveston Area Council explicitly endorsed such a system in 2004 (see attached letter). However, the TCEQ subsequently decided to adopt less aggressive prediction system - in fact, moving to a system that produced even fewer warnings than the one in effect at the time H-GAC endorsed a more proactive warning system. Because the TCEQ weakened the warning system, the public is not getting adequate information about air pollution levels.

The inadequate information about air pollution levels is manifested in two ways.

• Warnings are not being issued on certain days. Of four of nine recent ozone exceedances, no warning was issued.
• Warnings are not indicating the true geographic extent of the air pollution exposure. On those nine days, warnings were indicated for less than 50% of the monitors on seven days. Most important, when ozone levels were unhealthy across most of the Houston region on June 21 and June 22, the warnings only indicated problems in a small area.

The warning system is critical because few people make use of the actual air pollution data available on the TCEQ website. Broadcast media, in particular, are relying on the warning system to interpret the air pollution data and are not making independent assessments of air pollution conditions.

The TCEQ should adopt a warning system for the Houston region that is similar to the one endorsed by the Houston-Galveston Area Council last year. In the meantime, we have asked Harris County to issue special press advisories when conditions like June 21-22 develop to ensure that broadcast media provide appropriate information to the public.