U.S. EPA Contaminated Site Cleanup Information (CLU-IN)


U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division

Fractured Bedrock Project Profiles

Last Updated: March 22, 2010

Point of Contact:
Brian Vanderglas
8000 Centre Park Drive
Suite 200
Austin TX 78735 
Tel: 512-719-6000 
Email: Brian.vanderglas@
parsons.com

Camp Stanley Storage Activity
Boerne, TX


Hydrogeology:

Fractured bedrock with a water table between 100 to 300 feet below ground surface, depending on seasonal rainfall.

Targeted Environmental Media:
  • - Fractured Bedrock

Contaminants:

Major Contaminants and Maximum Concentrations:
  • - Tetrachloroethene (0 µg/L)
  • - Trichloroethene (0 µg/L)
  • - cis-1,2-Dichloroethene (0 µg/L)

Site Characterization Technologies:

  • - Other

Comments:
Though no site characterization technologies were identified within the references abstract, it did indicate that a tracer study is planned. It will be performed to assess the hydraulics of the bioreactor system as well as connectivity of the bioreactor to the underlying fractures and the aquifer.


Remedial Technologies:

No technologies selected.

Comments:
Waste and debris was removed from six disposal trenches and the trenches were backfilled with a mixture of 50% tree mulch and 50% pea gravel. In order to maintain moist conditions, contaminate groundwater was re-injected from a downgradient well approximately 400 feet from the bioreactor. The depth of the bioreactor was less than 20 feet and depth to the water table ranges from 100 to 300 feet below grade. Biological treatment of contaminants took place when carbon was delivered from the bioreactor into the vadose and saturated fractures. The water delivery system to the biobarrier was automated, capable of injecting up to 125 gallons per minute, and able to deliver biological enhancements.

The bioreactor began operating in April 2007 and performance monitoring data is available through at least April 2008. Monitoring took place via four multi-port monitoring wells containing 27 separate screened depth intervals. Bioreactor sumps were also installed to evaluate treatment and hydraulic conditions.
Remediation Goals:

None provided


Lessons Learned:

The hydraulics of the bioreactor system and the connectivity of the bioreactor to the underlying fractures and aquifer will be evaluated via a tracer study.

References:
Vanderglas, Brian, Chris Beal, Robert Edwards, and Glare Sanchez. Evaluating Treatment of Chlorinated Compounds in Fractured Bedrock Underlying Bioreactor. Presented at the Sixth International Conference on Remediation of Chlorinated and Recalcitrant Compounds. Monterey, CA. May 19-22, 2008.

Rice, Ken, Glare Sanchez, Chris Beal, Robert Edwards. Taking Advantage of Leaky Disposal Trenches in Fractured Bedrock, Poster Abstract Session A4. Presented at the Sixth International Conference on Remediation of Chlorinated and Recalcitrant Compounds. Monterey, CA. May 19-22, 2008.

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