Fill over highly fractured bedrock. Flow velocity in the bedrock was estimated to be 500 feet per year
Targeted Environmental Media:
 Dense Non-aqueous Phase Liquids (DNAPLs) - Fractured Bedrock
Lateral and vertical extent was not given in ROD or five-year reviews.
Major Contaminants and Maximum Concentrations:
- Tetrachloroethene (16 µg/L)
- Trichloroethene (930,000 µg/L)
- 1,2-Dichloroethene (730 µg/L)
- Vinyl chloride (19,000 µg/L)
- Acetone (1,900,000 µg/L)
- Surface Seismic Surveys
- Pump and Treat
Comments:
The source area system consists of three extraction wells (EW): EW01 pumping at 150 gallons per minute (gpm) provides hydraulic containment for the Neargradient Area exhibiting the presence of DNAPLs, and EW02 and EW03 pumping at approximately 200 and 100 gpm, respectively, provide containment and eventual restoration of the aquifer located in the non-DNAPL area (the Downgradient Area). EW01, EW02, and EW03 pump ground water to the ground water treatment system. The ground water treatment system uses the following processes to treat ground water extracted from EW01, EW02, and EW03: equalization; air-stripping; filtration; and liquid granular activated carbon.
The system has been operating since 1999.
Cleanup goals are MCLs for down gradient plume. The near gradient area has a finding of technical impracticability with the goal being containment.
The pump and treat system continues to operate. In a 2007 five year review a review of water quality data showed that there is a general decrease in TCE and acetone concentrations in the source area well during pumping conditions with variations in 1,2-DCE, total VOC, and vinyl chloride concentrations. The concentrations of these degradation products of TCE
have not stabilized and are still high. However, monitoring in downgradient wells has shown stabilization of these contaminants.
http://cfpub.epa.gov/supercpad/cursites/csitinfo.cfm?id=0301249
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