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: June 27, 2007

Point of Contact:
Derek Tomlinson
350 Eagleview Blvd., Suite 200
Exton PA 19341 
Tel: 610-524-3500 
Fax: 610-524-7335
Email: Derek.tomlinson@

Grownmark FS, Inc. Farm Center
East Berlin, PA


Predominant rock types within the fractured bedrock aquifer consist of siltstone and shale.

Targeted Environmental Media:
  • - Fractured Bedrock


The extent of the contaminant plume was approximately 2,000 feet from the source area.

Major Contaminants and Maximum Concentrations:
  • - Metolachlor (12,000 µg/L)
  • - Alachlor (4,600 µg/L)

Site Characterization Technologies:

No technologies selected.

Remedial Technologies:

  • - Other (Persulfate)
In the summer of 2005, a chemical oxidant was injected from a gravityfed, 1,000-gallon tank into the ground water at the site. Further information not provided in the source cited.
Remediation Goals:

The objective of the pilot study was to test whether a chemical oxidant injected into the fractured medium could follow the same path as the contaminants traveled during initial release, thus facilitating cleanup of the contaminated site.


The pilot study was completed in fall 2005, with a full-scale implementation planned for summer 2006.

Lessons Learned:

The oxidant was delivered via a batch injection infiltration gallery after the contaminated soil had been excavated and before clean fill was added. This approach was found the most cost-effective for this site.

References: Derek Tomlinson, Kristopher Saum, Shari Walsh, Gregory Smoot, and Dennis Newman. Cost-Effective ISCO Application within a Herbicide-Impacted Fractured Bedrock Aquifer. The Fifth International Conference on Remediation of Chlorinated and Recalcitrant Compounds. May 22-25, 2006. Monterey, California.

Top of Page