The Site is situated in Bexar County, in the City of Leon Valley, in the northwest section of the City of San Antonio, Texas. It consists of a plume with an estimated size of one mile long by one-half mile wide, extending from a business area to a residential area. The Site is bounded by Poss Road and Grissom Road, southwest of Bandera Road. Ongoing sampling and investigation may alter the estimated plume extent.
The Site currently includes six private drinking water wells that draw water from the Edwards aquifer. The wells are approximately 350 to 400 feet deep. The maximum observed concentration in the wells is 111.6 ppb of PCE and 5.76 ppb of TCE. The MCL for both is 5 ppb. PCE and TCE cannot be detected by taste or smell in water until it reaches concentrations well above the MCL. There are two City of Leon Valley public water supply wells within one mile of the center of the plume.
Releases or threatened release into the environment of a hazardous substance, pollutant or contaminant PCE has been detected above the MCL in six wells within the Site boundaries. PCE is a hazardous substance listed in Section 101(14) of CERCLA, 42 U.S.C. '9601(14) and 40 CFR '302.4. The Texas Department of Health and Human Services (DHHS) has determined that PCE may reasonably be anticipated to be a carcinogen.
The Site was added to the National Priorities List (NPL) on March 7, 2007.
EPA contractor mobilized to the site on May 8, 2007 and started trenching and installing water lines from the properties to the street. Three properties are now connected to the city water. The contractor is installing pressure regulators to prevent leaks due to a possible increase in the water pressure.
Four wells have been identified for sampling purposes. These wells do not represent a threat for the health of their owners, since none of them is being used as a drinking water source. Nonetheless its location will facilitate EPA studies. EPA has converted two of them into sampling stations by removing the existing pumps, and placing covers/caps and locks to prevent surface pollutants from entering the wells and to protect them from intruders.
Additional investigations are continuing to attempt to identify the source(s) and to define the extent of the plume.
On July 24, 2007 EPA staff from the Superfund Remedial and Removal Branches held a meeting open to the public to provide an update about the Bandera Road Groundwater Plume Site. The community meeting was held at the Leon Valley Conference Center. Personnel from the Texas Commission on Environmental Quality, the Texas Department of State Health Services, Edwards Aquifer and the City of Leon Valley were also present.
The removal action involves the installation of a water line and connection to public water systems. Currently, three of six properties have been connected to an existing water supply line from the City of Leon Valley. Other properties may be identified with contaminated wells as the investigation continues. The property owners will be responsible for paying for their water use. If the existing water wells are to remain in service, they will be isolated from the public system. Trenches and any disturbance of sidewalks, driveways, or other structures will be restored.
EPA and its contractor will continue working on the connection of the remaining three properties to the City water. Water pressure regulators will be installed in all of them. EPA contractor will convert the other two wells into sampling wells. The contractor will be fixing any damage caused by them to backyards, fences, sidewalks, etc.
Activated Carbon filters were installed in the wells by TCEQ, which will give the residents access to safe water before and during the removal actions. Once the removal actions are finished, residents will have immediate access to the city water.
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