By: Duane Craig
A plume of groundwater contamination is spreading below Bexar County along Bandera Road, and the Environmental Protection Agency, along with the Texas Commission on Environmental Quality, is considering next steps to deal with the current environmental issues.
The source of the contamination isn’t known. The contaminants include tetrachloroethene and trichloroethene in concentrations above the maximum contaminant level, or MCL, within the Edwards Aquifer. This site is named the Bandera Road Ground Water Plume and is in the northwestern portion of San Antonio. The plume is about a half mile wide and a mile long. It is centered in a business area, with some residential homes nearby, between Poss Road and Grissom Road, approximately 590 feet southwest of Bandera Road.
Originally, there were five private wells contaminated with the chemicals, and two city wells are within a mile of the plume. The plume is spreading, and investigators have now found the chemicals in a total of 12 wells. The original five affected wells now have carbon filters installed, and they are being sampled every six months. Three wells that are in the Edwards Aquifer have been abandoned and plugged. A well at an auto repair business has also been plugged. The most significant contamination occurs in a monitoring well near an old dry cleaning business. That well has concentrations of the chemicals as high as 11,700 parts per billion. During the planned remedial investigation, the EPA is also assessing the potential vapor intrusion pathways.