From TCEQ --

The Texas Commission on Environmental Quality (TCEQ) has removed one air pollutant (1,3-butadiene) from two areas of concern, in Port Neches and in Houston; and another (hydrogen sulfide) from a third area of concern in Beaumont. 

"The TCEQ is constantly undertaking a variety of efforts to improve air quality for the people of Texas," said TCEQ Chairman Buddy Garcia.  "In these watch list areas, we can focus all appropriate resources, and the result is cleaner air." 

"We are proud of these emissions reductions," said TCEQ Commissioner Bryan Shaw. "TCEQ has many ongoing air quality efforts, and we are always looking at new science and technology to improve our programs."

Because of the relatively large number of air monitoring sites in the Houston and Beaumont areas, the TCEQ has the ability to examine pollution levels of specific compounds at specific locations in order to address potential issues.

The TCEQ maintains an Air Pollutant Watch List (APWL), which is a list of areas in Texas where specific pollutants were measured at levels of concern. When an area is listed on the APWL, the TCEQ works with the regulated industry in the area to identify and reduce emissions and focuses agency resources such as facility inspections, field investigations, and enforcement activities.  Additionally, permitting of new or modified sources of these emissions undergo a more stringent review, encouraging concurrent reductions with the permitting actions.  Because of the successful reductions in air pollution of these specific compounds (see below), the monitored levels of these compounds have dropped significantly.  The agency has removed pollutants from three APWL areas because monitored levels of these pollutants have decreased below levels of concern.  This action eliminates two areas from the APWL and one pollutant from the third area.                                                  

Levels of 1,3-butadiene near Merriman Street in Port Neches and near Milby Park in Houston have been measured at levels of concern in the past, prompting their listing on the APWL.  Levels have fallen 75% in Port Neches since 1996 and in Houston since 2004 and are therefore no longer a concern in these areas.

In Beaumont, hydrogen sulfide was measured prior to 2005 at Carroll Street Park at levels that exceeded the TCEQ state standard. Since 2005, no exceedances were measured therefore the agency has determined that hydrogen sulfide concentrations are no longer a concern in this area.

TCEQ will continue to monitor these compounds to ensure that concentrations remain below the level of concern.

More information can be found at:  http://www.tceq.state.tx.us/implementation/tox/AirPollutantMain/APWL_index.html.