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: January 1, 2011

Point of Contact:
Tim Gallagher
USEPA 1650 Arch Street
Mail Code: 3HS21
Philadelphia PA 19103-2029 
Tel: 215-814-3196 
Email: gallagher.tim@
pa.gov

Hellertown Manufacturing Company
Hellertown, PA


Hydrogeology:

The site is underlain by Cambrian and Pre-Cambrian rocks that have been deeply weathered. The Tomstown Formation (also known as the Leithsville Formation) lies directly under the site and is composed primarily of dolomitic limestones with varying amounts of lime-containing shales and phylitic schists. Some highly weathered sandstone lenses may be found in the formation as well. The geologic structure of the rocks is extremely complex, which is partly caused by extensive thrust faulting in the area. The Tomstown Formation extends to a depth of approximately 1,000 feet, with the upper few hundred feet reportedly containing all of the water-bearing fractures. The bedrock in the vicinity of the site is overlain by saprolite and a mantle of undifferentiated alluvium and colluvium. The combined thickness of these units ranges from zero to 41 feet in the vicinity of the site.

The bulk of the regional groundwater moves through carbonate-rock formations, including the Leithsville Formation, that are most likely interconnected hydraulically. Most of the water in the carbonate-rock aquifers occurs in bedding-plane openings, joints, fault zones, and fractures that have been enlarged by groundwater dissolving minerals from the rock. The flow pattern in the bedrock in the vicinity of the site is complex; however, water level measurements in monitoring wells indicate that groundwater is discharging to Saucon Creek. There is generally a downward and horizontal (westerly) groundwater flow in the alluvium/colluvium mantle and an upward and horizontal (westerly) groundwater flow in the Leithsville Formation.

Targeted Environmental Media:
  • - Fractured Bedrock

Contaminants:

The areal extent of the plume is about 7.5 acres. The vertical extent was not given in the ROD or five-year reviews.

Major Contaminants and Maximum Concentrations:
  • - Tetrachloroethene (22 µg/L)
  • - Trichloroethene (1,700 µg/L)
  • - 1,2-Dichloroethene (260 µg/L)
  • - Vinyl chloride (83 µg/L)
  • - Benzene (Not given)

Site Characterization Technologies:

No technologies selected.


Remedial Technologies:

  • - Pump and Treat
Comments:
An extraction well drilled to replace the one installed in 1996 began operation in 1999. Monitoring wells are routinely tested for contaminants of concern.
Remediation Goals:

Cleanup goals were background or MCLs.


Status:

The extraction well continues to operate although there have been problems with pump failures. In general, it appears that the trend of contaminant concentrations has decreased in all three of the aquifers beneath the site (overburden, shallow bedrock, and deep bedrock) and most
wells since 1999.

Modifications to the system have been to heat the building in winter to 40 and they have removed the carbon unit due to low levels of contaminants in the air stripper effluent.

http://cfpub.epa.gov/supercpad/cursites/csitinfo.cfm?id=0300623

Top of Page

For more information on Fractured Bedrock, please contact:

Ed Gilbert
Technology Assessment Branch

PH: (703) 603-8883 | Email: gilbert.edward@epa.gov