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 4, 2011

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

Occidental Chemical Corporation
Lower Pottsgrove Township, PA


The overburden soils at the Site consist of alluvium, fill, and weathered bedrock. The overburden in the vicinity of the plant area is 8 to 11 feet thick and consists of silty sand fill with some gravel and cobbles. The overburden beneath the plant area is also largely unsaturated with the exception of a perched water zone in the vicinity of the concrete basins of the wastewater treatment plant.

The geology underlying the Site consists of two formations of Triassic age: the Brunswick Formation and the Lockatong Formation. The Brunswick Formation consists of thin to medium bedded, reddish-brown shale, mudstone, and siltstone. The Lockatong Formation consists of predominantly massively bedded, medium to dark gray argillite, interbedded with thin beds of gray to black shale, siltsone, and marlstone. The formations strike 80 east, with the bedding planes dipping from about 13 to 18 toward the north. Jointing is abundant and nearly vertical in the bedrock. The Lockatong Formation is more massive, with fewer joint sets than the Brunswick Formation. One well-developed joint set and two less abundant sets exist in the Brunswick, with orientations measured at north 30 east, north 75 east, and north 45 west, respectively.

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


The vertical extent of contamination is believed to be at least 582 feet bgs.

Major Contaminants and Maximum Concentrations:
  • - Trichloroethene (91,000 µg/L)
  • - 1,2-Dichloroethene (0 µg/L)
  • - Vinyl chloride (0 µg/L)
  • - Ethylbenzene (0 µg/L)
  • - Styrene (0 µg/L)

Site Characterization Technologies:

  • - Fracture Trace Analysis
  • - Coring

Remedial Technologies:

  • - Pump and Treat
The pump and treat system was completed in 1999.
Remediation Goals:

Cleanup goals are MCLs.


The system continues to operate.

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