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: December 15, 2004

Point of Contact:
Charles Race
Tetra Tech NUS Inc.
55 Jonspin Rd.
Wilmington MA 01887 
Tel: 978-658-1228 
Email: racec@ttnus.com

DNAPL Site
Eastern Area, ME


Hydrogeology:

Fractured crystalline gabbro-diorite

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

Contaminants:

The contaminant source in soil was removed in 1999; however, the plume was approximately 180 ft. long, 200 ft. wide and 200 ft. thick.

Major Contaminants and Maximum Concentrations:
  • - Tetrachloroethene (7,200 µg/L)

Site Characterization Technologies:

  • - Coring

Remedial Technologies:

  • - Chemical Oxidation (In Situ)
    • Permanganate
Comments:
In initial pilot tests, it was concluded that recirculation of ground water amended with permanganate was necessary to improve oxident delivery to the PCE source zone. An estimated 900,000 gallons of treated water was amended with 385 gallons of 40% NaMnO4 during five months of recirculation in August 2002. Post-treatment monitoring, while the system was shutdown indicated PCE rebounded to 6,600 ug/L at a source well 8 months after shutdown.
Remediation Goals:

This was a pilot test.


Status:

Options are being considered to enhance the connectivity of the bedrock fractures in the contaminant source zone.

This information was reported in the 2004 U.S.EPA/NGWA Fractured Rock Conference, September 13-15, 2004, Portland, ME


Lessons Learned:

Complete oxidation of the PCE source was limited by delivery of insufficient oxidant mass to the source zone relative to the mass of the PCE source. Heterogeneities limited delivery.

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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