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:
Holly Holbrook
300 Oceangate
Suite 700
Long Beach CA 90802 
Tel: 562-951-2000 
Email: Holly.Holbrook@

Edwards AFB  Site 177/325
Edwards AFB, CA


The geology of the site consists of fractured granitic bedrock. Groundwater occurs within the bedrock fractures.

Targeted Environmental Media:
  • - Fractured Bedrock


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

Site Characterization Technologies:

  • - Borehole Geophysics
    • Acoustic Televiewer
    • Video Camera Televiewer

The pilot study at the site was performed in two phases. Site characterization for the initial phase was not identified in the abstract referenced. Additional characterization during the second phase was performed using reverse circulation air rotary drilling, optical and acoustic televiewing, and additional monitoring wells.

Remedial Technologies:

  • - Bioremediation (In Situ)
    • Reductive Dechlorination (In Situ Bioremediation)
In November 2005, a Hydrogen Release Compound (HRC) primer and HRC were introduced perpendicular to the direction of groundwater flow via three injection wells as part of the two part pilot study. Chlorinated solvents were reduced within downgradient wells proportional to the amount of HRC but did not degrade past cist-1,2-dichloroethene. Perchlorate was reduced completely or almost completely in all but two of the wells. Study wells were sampled in November 2007 to obtain the status of the HRC and collect Phase II baseline data.
Remediation Goals:

None provided


Phase II of the study was planned to start in the summer of 2008 and involve bioaugmentation and the injection of a more soluble slow-release electron donor. This will include injection of the show-release electron donor, 3D Microemulsion (3DMeTM) to achieve better distribution. Post-injection monitoring was anticipated for 18 months.

Lessons Learned:

Holbrook, Holly, Rebecca H. Mora, Sara Grossi, and Practice Hallman. Pilot Study Using Hydrogen Release Compound in Fractured Granitic Bedrock, Poster Abstract Session D7. Presented at the Sixth International Conference on Remediation of Chlorinated and Recalcitrant Compounds. Monterey, CA. May 19-22, 2008.

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