Published: September 13, 2008 08:42 am      

Edwards Aquifer: Site focus of EPA monitoring, probe

A documented plume of contaminated groundwater in northwest Bexar County remains the focus of monitoring and investigation by the Environmental Protection Agency (EPA), Edwards Aquifer Authority directors were told at their regular meeting this week.

A portion of San Marcos’ municipal water supply is pumped from the aquifer.

Chris Villareal, remedial project manager with the EPA, reported to the authority board that the contaminated groundwater area in Leon Valley remains on the EPA National Priorities List of Superfund sites.

As a result, the site is eligible for federal funds for clean up efforts, according to Villareal.

In his presentation, Villareal noted that the chemical tetrachloroethylene, also known as perchloroethylene (PCE), was previously detected in some private wells, but has yet to be found in public water supplies. 

He also reported that the contaminated plume area, estimated to be one mile long by one-and-a-half mile wide in the vicinity of Bandera Road in Leon Valley, has not expanded beyond its previously known boundaries.

According to Villareal, residents with private wells affected by the contamination plume have been connected to public water supply lines so that presently there are no people drinking water with PCE levels above the safe drinking water standard.

PCE is a manmade solvent used commercially as an industrial degreaser and spot remover used in dry cleaning.