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: August 3, 2011

Point of Contact:
Grant Scholes
Unknown United States 00000 
Tel: 222-222-2222 
Email: gscholes@

Active Industrial Site in Southern Ontario
Unknown, ON, Canada


Not identified in the references cited.

Targeted Environmental Media:
  • - Dense Non-aqueous Phase Liquids (DNAPLs)
  • - Fractured Bedrock


Not identified in the references cited.

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

Site Characterization Technologies:

No technologies selected.

Remedial Technologies:

  • - Bioremediation (In Situ)
    • Reductive Dechlorination (In Situ Bioremediation)
Naturally-occurring dechlorination of tetrachloroethene (TCE) was taking place on site; however, a recirculation-based enhanced in situ bioremediation (EISB) system was implemented in 2008 to prevent plume migration and to accelerate dechlorination. EISB was selected based on various technical and practical factors such as the existence of nearby wetlands, the ongoing naturally-occurring dechlorination, restrictions on near-by sewer use, and facility and neighboring operations.

The EISB system includes:
ýGroundwater extraction wells (3)
ýAmendment infrastructure for ethanol (electron donor) and bromide (tracer)
ýInfrastructure for chlorine dioxide addition (biofouling control)
ýRecharge wells with operating capacity of 100 gallons per minute (5)

Remediation Goals:

Not identified in the references cited.


From 2008 to 2010, the system has reduced cis-1,2-DCE concentration at the site boundary by more than 70 percent and dechlorination within the source area is slowly increasing. In the fall of 2009, KB-1ý will be injected into the plume in areas with the highest TCE concentrations to facilitate bioaugumention.

Lessons Learned:

Elevated sulfate levels (>500 mgL) are being reduced and the sulfide production in the groundwater is restoring EISB dechlorination rates to initial levels. Dechlorination and Dehalococcoides are being monitored for further impacts from sulfide production.

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