The stratigraphy of the site is relatively simple with a thin layer of unconsolidated sediments, ranging from
5 to 30 feet (thickest in the southern portion of the site and thinnest to the north), overlying sedimentary bedrock units. At the ground surface across most of the site is a layer of fill and disturbed soil consisting of sand, silt, gravel, demolition debris, and waste material in some areas. This layer is as thin as 1 foot to the north of the site and as thick as 18 feet in the southern portion of the site. In the Main Plant Area, there is a 2 to 4 foot thick layer of man-made fill and construction rubble. Alluvial deposits of silt and clay are generally found beneath the fill and disturbed soil layer, ranging from 1 to 4 feet in thickness, although this layer is generally absent in the Main Plant Area. Beneath this unit are alluvial deposits of sand and gravel, with varying amounts of silt. This unit typically ranges from 3 to 15 feet in thickness and is the location of the major overburden aquifer in the area. A silt and clay layer is occasionally present at the base of this unit, believed to be derived from erosion of a thin local layer of weathered shale. Residual shale fragments are also found locally. Where present, this clay and fractured shale layer acts as a low
permeability boundary between the overburden aquifer and an underlying bedrock aquifer. Beneath these deposits lies a series of reddish-brown shale, siltstone, and fine-grained sandstone known as the Passaic Formation bedrock. The maximum estimated thickness of bedrock in the Passaic Formation reaches
approximately four miles. Extensive jointing of the formation has been observed, with three predominant
transmissive zones in the area of the AHP property. The bedrock surface exhibits little relief in the area,
but a bedrock high is present in the western portion of the site. The bedrock surface under the Main
Plant Area is eroded and forms a valley toward the Raritan River in the southeastern corner of the site.
Two extensive zones of joints and fractures have been identified beneath the site, and have been designated as the highly and moderately transmissive zones. These two transmissive zones are separated by zones of more competent (less permeable) bedrock. A third zone, the SS transmissive zone, has been identified adjacent to the Raritan River.
Targeted Environmental Media:
 Fractured Bedrock
There are numerous plumes at the site caused in part by leakage from some of the 27 impoundments.
Major Contaminants and Maximum Concentrations:
- Benzene (1,110 µg/L)
- Chlorobenzene (1,490 µg/L)
- Tetrachloroethene (28 µg/L)
- Trichloroethene (13 µg/L)
- 1,2-Dichloroethene (73 µg/L)
- Nitrobenzene (58 µg/L)
- 1,2,4-Trichlorobenzene (229 µg/L)
- Carbon tetrachloride (11 µg/L)
No technologies selected.
- Pump and Treat
Comments:
Contaminant maximum concentrations were from 2003 sampling round. Groundwater contaminant plumes are controlled by non-contact cooling water production wells set at a depth of 250 to 290 feet bgs. The wells pump 650,000 gallons a day and draw water from both the overburden and bedrock aquifers.
Remediation goals for groundwater have not been set.
As of 2008 a site wide feasibility study for groundwater was being developed. No groundwater ROD has been issued
http://www.epa.gov/region02/waste/fsamhome.htm
http://cfpub.epa.gov/supercpad/cursites/csitinfo.cfm?id=0200144
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