Underlying the facility is the Triassic-aged Brunswick Formation. This red, argillaceous shale formation is inter-bedded with greenish shale, siltstone, and red, fine-grained sandstone. The intense fractures in the upper 300 feet of this formation provide storage for groundwater. Groundwater depth at the former Tenneco site typically ranges from 10 to 30 feet below ground surface, however, depth to groundwater at the pumping wells are greater due to the draw-down effect.
Targeted Environmental Media:
 Fractured Bedrock
The extent of the plume was not given.
Major Contaminants and Maximum Concentrations:
- Trichloroethene (20,000 µg/L)
- Vinyl chloride (6,000 µg/L)
- 1,2-Dichloroethene (Not given)
- Methylene chloride (Not given)
No technologies selected.
- Chemical Oxidation (In Situ)
- Pump and Treat
- Multi Phase Extraction
Comments:
The groundwater recovery system was
put into service in 1987. In 1997, the recovery system was expanded to remediate additional areas. The
system currently consists of six recovery wells installed into the bedrock. Water is extracted at a combined rate of 40 gallons per minute (gpm) and is treated by two 1,500 pound granular activated carbon (GAC) units. Treated water is subsequently discharged to the Raritan Township Municipal Utilities Authority (RTMUA).
The system has been running approximately 20 years.
Cleanup levels are the New Jersey Ground Water Quality Standards.
Groundwater contamination at the former Tenneco site appears to have stabilized both in terms of the overall contaminant concentration level and areal extent. As the recovery system continues to operate, the concentrations of each constituent has been steadily declining since 1987. The historical data indicate a clear decreasing trend for all constituents. For example, the levels of methylene chloride and tran-1,2, dichloroethylene are no longer detected at levels above the NJDEP Groundwater Quality Standards (GWQS), and the levels of TCE and
vinyl chloride indicate a general downward or stable trend at almost all monitoring wells. At well TP-08,
the TCE levels were 4200 ug/L in 1996, 550 ug/L in 1998, 300 ug/L in 2004, 50 ug/L in 2006, and below 40 ug/L in 2007. At well FM-3, the concentration level of TCE has dropped dramatically from 20,000 ug/L in 1995 to 200 ug/L in October 2007.
Facility perimeter wells are generally below 5 ug/L of TCE and non-detect for vinyl chloride.
http://www.epa.gov/region02/waste/fselpaso.htm
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