One of the reasons the Federal Highway Administration likely pushed TxDOT to prepare a full Environmental Impact Statement for the Bandera Rd elevated toll project aside from the toll controversy is the toxic plume discovered under Leon Valley. An elevated toll road has the potential to aggravate the already tenuous hazardous water situation in Leon Valley. The last thing this area needs is further road expansion which is known to pollute water.
Link to article here.
Health assessment released for Superfund site
A draft public health assessment released Tuesday for a portion of the Edwards Aquifer that in March landed on the national Superfund list shows higher-than-normal rates of four birth defects but concludes that the rates aren’t statistically significant.The Environmental Protection Agency put the site near Bandera and Grissom roads on the list of critically contaminated sites because of concerns about the region’s primary source of drinking water.
A dozen private wells have showed contamination with perchloroethylene, or PCE, with six of those reaching levels above federal drinking water standards. But after the pollution was discovered in 2004, the Texas Commission on Environmental Quality placed carbon filters on the six wells.
The EPA this year has paid to have three of the six wells hooked up to a public supply system and is working to get the other three connected, Cindy Santiago, on-scene coordinator with the EPA, told about 15 people gathered Tuesday night at the Leon Valley Conference Center for an update on the site.
Carrie Bradford, a toxicologist with the Texas Department of State Health Services, said the recently completed draft public health assessment showed no increased prevalence of cancers in the two ZIP codes around the site. But the data for 1997 through 2003 showed four of 48 types of birth defects were significantly elevated among residents of Leon Valley.
But after adjusting for maternal age and ethnicity, the prevalence of those defects was “no longer statistically significantly different from the statewide prevalences,” the report says, though it goes on to caution that the rates were still high.
Bradford said no current or future exposures or health effects are expected from the pollutants, provided that people don’t drink unfiltered, contaminated water.
The draft assessment is out for 30 days of public review and comment.
The plume of polluted water is about a mile long and a half-mile wide but is still up to a mile away from any public supply wells owned by Leon Valley.
Chris Villarreal, the EPA’s remedial project manager for the site, said officials believe the chemical entered or is entering the aquifer through the borehole for a water well because the aquifer in that area is thought to be protected by layers of impermeable rock. The borehole may be deteriorated, improperly constructed, incorrectly sealed or abandoned.
That’s why the initial investigation has focused on identifying wells in the area, he said, noting that a survey by the U.S. Geological Survey has found about 70 wells.
Soon, as authorities set up some of those wells for monitoring, they’ll attempt to better characterize the plume and the aquifer in that area, Villarreal said.
As for the source, state investigators have identified 51 potential sources within a 2-mile radius for the chemical and its byproduct, trichloroethylene, which also has been found in the plume.
PCE has been used in dry cleaning and as a degreasing agent.
Exposure to high concentrations of the two chemicals over long periods can cause liver and kidney damage and cancer.
Link to article here.
EPA to hold meeting on Superfund project
Web Posted: 07/22/2007 10:08 PM CDT
The U.S. Environmental Protection Agency has scheduled a meeting Tuesday to update the public on the status of activities at the Bandera Road Groundwater Plume Superfund Site in Leon Valley.
The meeting is scheduled for 7 p.m. at the Leon Valley Conference Center at 6427 Evers Road, said Chris Villarreal, EPA’s remedial project manager for the site.
“Mostly, we’re just going to bring people up to date as to what information we have and what additional activities are planned for the next six to nine months,” said Villarreal, who is based in Dallas.
The site over the Edwards Aquifer was placed on the federal government’s list of polluted sites requiring immediate attention March 7 because of its potential to affect the region’s primary drinking water source.
Located near Bandera and Grissom roads, a plume of perchloroethylene has polluted almost a dozen private wells. Authorities are trying to pinpoint the source. The chemical has commonly been used as a dry-cleaning agent and an industrial degreasing agent.
State health officials also may discuss efforts they’re undertaking to conduct a public health assessment for the site, Villarreal said, adding that a half-hour of presentations will be followed by a question-and-answer session.