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:
Darko Strajin
1595 Clark Boulevard
Brampton ON L6T 4V1 
Tel: 905-793-9809 
Email: Darko.strajin@
trow.com

Unknown Dry Cleaning Facility
Unknown


Hydrogeology:

Soils consist of clays and silts with sandy fill materials over weathered shale bedrock. Bedrock is encountered at 3 feet below ground surface (bgs) and groundwater is present within the bedrock.

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

Contaminants:

Not identified in the references cited.

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

Site Characterization Technologies:

No technologies selected.


Remedial Technologies:

  • - Chemical Oxidation (In Situ)
    • Ozone
Comments:
The in situ remedial technology is called Perozoneř and consists of the injection of gas phase ozone and hydrogen peroxide (aqueous). The two oxidants are introduced into the subsurface through sparge points that are designed to form microscale hydrogen peroxide-coated bubbles of ozone. The injection system functions continuously and between sparge points, repeatedly cycling the injections. The system operated for a 3-month pilot and was then implemented full-scale.
Remediation Goals:

CVOC provincial criteria ř 17 ug/L


Status:

Review of groundwater VOC analytical data obtained throughout the 3-month pilot test indicated that the technology had a significant radius of influence and the potential to lower chlorinated VOC concentrations if implemented at the full-scale.

After a year and a half of full-scale application, off-site property objectives were met and PCE within the groundwater on site met the provincial criteria. Groundwater PCE levels were sufficiently decreased in order to implement a risk assessment that indicated further action through limited vapor mitigation measures.


Lessons Learned:

References:
Strajin, Darko. 2011. Treating Chloroethenes in Shallow Fractured Rock. From The 21st Annual International Conference on Soil, Water, Energy, and Air. March 14-17, 2011, San Diego, California.

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For more information on Fractured Bedrock, please contact:

Ed Gilbert
Technology Assessment Branch

PH: (703) 603-8883 | Email: gilbert.edward@epa.gov