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: October 29, 2010

Point of Contact:
Byron Mah
US EPA 5 Post Office Square Suite 100
Mail Code: OSRR07-1
Boston MA 02109-3912 
Tel: 617 918-1249 
Email: mah.byron@
epa.gov

Barkhamsted-New Hartford Landfill
Barkhamsted, CT


Hydrogeology:

The bedrock at the Site is predominantly micaceous schist with thin beds of amphibolite and pegmatite intrusions. The designation shallow bedrock generally refers to the upper 10 to 20 feet. The ranges of values for the shallow and
intermediate bedrock hydraulic conductivities were 0.001 to 43 ft/day.

Targeted Environmental Media:
  • - Fractured Bedrock

Contaminants:

The overburden plume in 2003 was stable and approximately 840 feet wide and 1,560 feet long. By 2008 it had shrunk to approximately 360 feet by 480.

The shallow bedrock plume in 2003 was stable and approximately 1,380 feet wide by 2,000 feet long. By 2008 it was 720 feet wide by 1,000 feet long.

The vertical extent of the plume is generally between 10 and 50 feet below the ground surface. Lesser concentrations of contaminants occur in wells in the deep bedrock aquifer, at depths of about 200 feet. ````````````````````````````````````````````````````````

Major Contaminants and Maximum Concentrations:
  • - Acetone (18,000 µg/L)
  • - Benzene (17 µg/L)
  • - 2-Butanone (MEK) (37,000 µg/L)
  • - 4-Methyl-2-pentanone (MIBK) (2,200 µg/L)
  • - Toluene (23,000 µg/L)
  • - Trichloroethene (43 µg/L)
  • - Vinyl chloride (19 µg/L)
  • - 2,4-Dimethylphenol (2,200 µg/L)
  • - 4-Methylphenol (p-cresol) (51,000 µg/L)
  • - Chromium (222 µg/L)

Site Characterization Technologies:

No technologies selected.


Remedial Technologies:

  • - Other (Monitored Natural Attenuation)
Comments:
Cleanup projected to take 16 years.
Remediation Goals:

Cleanup levels were set at background which for the organics is generally less than 1 ug/L.


Status:

Since completion of the cap in 1998, the contaminants for which groundwater cleanup levels were established have decreased in concentration. Many contaminants are below the MCL and some are at or approaching the respective cleanup goal of background concentrations in recent sampling events.

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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