The Site is located in the Chester Valley, underlain by carbonate and clastic rocks of Cambrian and Ordovician age. The immediate area of the Site is underlain by the Ledger Dolomite and Elbrook Limestone Formations. Recent overburden deposits across the Site consist of fine-grained
soils overlying bedrock. Overburden deposits range in thickness from 30 to 120 feet.
The bedrock aquifer underlying the Site is generally unconfined and is recharged by local precipitation. Groundwater flows through a network of interconnected secondary openings that
include joints, faults, bedding planes, and fractures. In May 1996, the mean depth to groundwater at the Main Plant Area was 70 feet.
Targeted Environmental Media:
 Dense Non-aqueous Phase Liquids (DNAPLs) - Fractured Bedrock
The plume is about 200 feet wide and may be as deep as 178 feet bgs.
Major Contaminants and Maximum Concentrations:
- Tetrachloroethene (7,110 µg/L)
- Trichloroethene (53,900 µg/L)
- 1,1,1-Trichloroethane (Not given)
- 1,1,2-Trichloroethane (Not given)
- 1,1-Dichloroethene (Not given)
- 1,2-Dichloroethane (Not given)
- Carbon tetrachloride (Not given)
- Chloroform (Not given)
- 1,2-Dichloroethene (Not given)
- Vinyl chloride (Not given)
No technologies selected.
- Bioremediation (In Situ)
- Reductive Dechlorination (In Situ Bioremediation)
- Other (Monitored Natural Attenuation)
Comments:
The in situ bioremediation system became operational in March 2010. It consists of seven injection wells and five extraction wells. Sodium Lactate is the biostimulant.
Monitored natural attenuation was chosen for the second less contaminated plume.
Cleanup goals are MCLs.
Concentrations in the disposal area plume (MNA area) having been declining. The site vadose zone SVE system has removed over 11,000 pounds of VOCs. The Bioremediation/recirculation system is operating as designed.
http://cfpub.epa.gov/supercpad/cursites/csitinfo.cfm?id=0300868
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