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:
Julie vander
130 Research Lane
Suite 2
Guelph ON N1G 5G3 
Tel: 519-822-2230 
Fax: 519-822-3151
Email: jkonsuk@
geosyntec.com

Unknown
Unknown , PA


Hydrogeology:

The site consists of inter-bedded shale and siltstone 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 (100 µg/L)

Site Characterization Technologies:

No technologies selected.


Remedial Technologies:

  • - Chemical Oxidation (In Situ)
    • Permanganate
Comments:
In situ chemical oxidation (ISCO) treatments targeted primary fracture migration pathways, focusing on a suspected dense nonaqueous phase liquid (DNAPL) source zone for mass treatment. Groundwater recirculated with permanganate amendment prevented off-site migration of permanganate, while distributing the permanganate throughout treatment area. Permanganate waste and consumption was minimized through the use of pulsed injection followed by rebound monitoring in targeted rebound areas.
Remediation Goals:

Not identified in the references cited.


Status:

Permanganate was effectively distributed over a wide area. Substantial mass destruction was demonstrated by chloride concentration increases to 1,000 milligram/liter (mg/L). Over 1,350 pounds (lbs) of TCE have been destroyed, as well as 945 lbs of DNAPL/sorbed mass. A theoretical pump and treat system removing 2 mg/L TCE and running at 20 gallons per minute, would need to run for 110 years and would extract 10.5 million gallons of water per year to achieve the same results.


Lessons Learned:

ıIt is important to understand contaminant migration pathways.
ıTreatment is labor intensive.
ıActual mass of permanganate required was greater than what was estimated.
ıPhased injections allow for: (1) assessment of rebound potential; (2) detection of DNAPL areas through the use of parent to daughter dechlorination ratios; (3) more focused treatment, lowering groundwater issues and costs through targeted permanganate application.
ıAnticipate contaminant rebound; therefore, plan for multiple injections.
ıIt is unlikely that this process will allow cleanup to maximum contaminant levels (MCL).

References:
Konzuk, Julie; Suzanne OıHara; Karen Berry-Spark; Mark Watling; and Evan Cox. 2010. Lessons Learned from Full-Scale Implementation of In Situ Chemical Oxidation in Fractured Bedrock. From Seventh International Conference on Remediation of Chlorinated and Recalcitrant Compounds, May 2010, Monterey, CA.

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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