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 2, 2011

Point of Contact:
Clifford Ng,
USEPA
290 Broadway
New York NY 10007-1866 
Tel: 212-637-4113 
Email: ng.clifford@
epa.gov

Ortho-Clinical Diagnostics
Raritan, NJ


Hydrogeology:

The site lies within the Piedmont Physiographic Province (Triassic Lowlands) which is characterized mainly by gently rounded lowland hills separated by wide valleys. The site is underlain by the Passaic Formation, which consists of non-marine, reddish-brown mudstone, shale, siltstone, and fine-grained sandstone interbedded with a lesser amount of gray to black siltstone, shale, and mudstone. The strike of the bedrock in the vicinity of the site is due North to N10 W and the dip is approximately 8 to 11 to the east-northeast. Bedrock is encountered at an approximate depth of 3 to 12 feet below grade and is composed predominantly of weathered reddish-brown shale and siltstone. More competent bedrock zones are typically encountered below a depth of 30 feet.

The Passaic Formation is composed primarily of relatively impermeable materials, and derives its water-bearing properties mostly due to secondary porosity in the form of bedding plane fractures, near-vertical joints, and weathered zones within the formation. Two water-bearing zones have been identified at the site during the RCRA Facility Investigation (RFI). The first water-bearing zone typically occurs in the shallow weathered bedrock within a depth of approximately 40 feet. The depth to water in monitoring wells screened within this zone varies from 6 to 28 feet below grade. The predominant groundwater flow direction in the shallow bedrock zone is toward the south. The shallow water-bearing unit appears to be separated from a deeper water-bearing zone by more competent beds in the Passaic Formation as evidenced by a hydraulic head differential of approximately 40 feet between the two zones. The depth to water in monitoring wells screened in the deep bedrock zone ranges from 48 to 67 feet below grade. Where fractures are encountered, the deeper bedrock zone is typically characterized by a higher permeability than the shallower zone.

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

Contaminants:

Major Contaminants and Maximum Concentrations:
  • - Trichloroethene (56,000 µg/L)
  • - Benzene (69 µg/L)
  • - Vinyl chloride (33 µg/L)
  • - Chloroform (Not given)
  • - 1,2-Dichloroethene (Not given)

Site Characterization Technologies:

No technologies selected.


Remedial Technologies:

  • - Pump and Treat
  • - Bioremediation (In Situ)
    • Reductive Dechlorination (In Situ Bioremediation)
Comments:
The pump and treat system does not belong to the facility but rather is an offsite industrial production well with a large deep bedrock capture zone. It is not used for shallow bedrock capture.

The reductive dechlorination effort using dilute molasses was begun in 2004 with repeat injection into 20 wells. TCE in the source area and down gradient plume have experienced a significant downward trend.
Remediation Goals:

New Jersey Groundwater Quality Standards.


Status:

The full-scale injection system has reduced TCE concentrations to less than 10 ug/L throughout the entire on-site plume outside the source area. Furthermore, approximately 50% of the on-site plume (outside the source area) currently has TCE concentrations of less than 1 ug/L. However, concen-trations within the source area while lower are still high (19,500 ug/L from 39,750 ug/L).

http://www.epa.gov/region02/waste/fsortho.html

Top of Page