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 18, 2001

Point of Contact:
Tony Manion
US Dept of Energy
200 Administration Rd. Box 2001
Oak Ridge TN 37830 
Tel: 865-576-5691 
Email: maniot@
oro.doe.gov

DOE Y-12 Plant
Oak Ridge, TN


Hydrogeology:

The uppermost stratigraphic sequence is the Knox Group, a prominant interval of dolomites and limestones. The primary permeability is very low; however, diagensis, fracturing, and solution weathering have resulted in secondary porosity and increased permeability through which most ground water movement occurs.

Ground-water movement within the siliclastic units is dominated by fracture flow. Ground-water movement in the carbonate-dominant formations has components of both fracture flow and flow through solution-enlarged cavities and conduits. Hydraulic conductivities calculated indicate a five order of magnitude range (10-3 to 10-8 cm/s).

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

Contaminants:

CCL4 has been found at depths greater then 450 ft. bgs.

The maximum concentration of CCL4 (8.5 mg/L recorded in 1989) exceeds 1% of the pure phase solubility (7.8 mg/L), suggesting the presence of DNAPLs.

Major Contaminants and Maximum Concentrations:
  • - Carbon tetrachloride (800 µg/L)
  • - Chloroform (var)
  • - Tetrachloroethene (500 µg/L)
  • - Trichloroethene (200 µg/L)
  • - Methylene chloride (var)

Site Characterization Technologies:

No technologies selected.


Remedial Technologies:

  • - Pump and Treat
Comments:
A pump and treat system was installed for plume control. Dissolved concentrations of carbon tetrachloride are high enough to indicate DNAPL. Bioremediation was identified as the technologically most plausible enhancement to replace the current pump and treat system.
Remediation Goals:

The goals is for ground water beyond the boundry to be protected as a future drinking water source. The primary target contaminant is CCl4 and the MCL is 5 ug/L .


Status:

A deep delivery system for bioaugmentation and biostimulation is being designed.

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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