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:
Melissa A. Boysun
300 Oceangate
Suite 700
Long Beach CA 90802-4391 
Tel: 512-346-9947 
Email: Melissa.boysun@
earthtech.com

Edwards AFB  Site 162
Edwards AFB, CA


Hydrogeology:

Site geology consists of fractured granitic bedrock. The groundwater travels within the competent bedrock through highly degraded fractures.

Targeted Environmental Media:
  • - Fractured Bedrock

Contaminants:

Major Contaminants and Maximum Concentrations:
  • - Tetrachloroethene (0 µg/L)
  • - Trichloroethene (0 µg/L)

Site Characterization Technologies:

  • - Borehole Geophysics
    • Acoustic Televiewer
    • Video Camera Televiewer
  • - Tracer (dye) Test

Comments:
The pilot study at the site was performed in two phases. Site characterization for the initial phase is not indicated in the reference; however, for the design of the second phase, additional lithologic and hydrogeologic characterization was achieved using a tracer test with three different tracers, reverse circulation air rotary drilling, optical and acoustic televiewing, and observation wells (including one multilevel well).


Remedial Technologies:

  • - Bioremediation (In Situ)
    • Reductive Dechlorination (In Situ Bioremediation)
Comments:
Phase I of the pilot study took place in December 2005 and consisted of 1,530 liters of Emulsified Oil Substrate (EOS) solution and 285 liters of chase water introduced via three injection wells oriented perpendicular to the groundwater flow. Performance monitoring took place for a year after injection. Phase II of the pilot study was set to be implemented in 2008 and combined EOS with bioaugmentation.
Remediation Goals:

None provided


Status:

Phase I results revealed stalled PCE dechlorination at cis-1,2-dichloroethene and concentrations rebounded as the electron donor was depleted and redox conditions became more oxidizing.


Lessons Learned:

References:
Boysun, Melissa A, Rebecca H. Mora, Sarah Grossi, and Patrice Hallman. Subsurface Characterization in Support of an in Situ Bioremediation Pilot Study in Fractured Granitic Bedrock, Platform Abstract Session A4. Presented at the Sixth International Conference on Remediation of Chlorinated and Recalcitrant Compounds. Monterey, CA. May 19-22, 2008.

Top of Page