Sand and gravel overlaying fractured shale. DNAPL penetrated two feet into the fractured shale.
Targeted Environmental Media:
 Dense Non-aqueous Phase Liquids (DNAPLs) - Fractured Bedrock
DNAPL had penetrated the upper two feet of the Sunbury Shale.
Major Contaminants and Maximum Concentrations:
- Trichloroethene (97,000 µg/L)
No technologies selected.
- Thermal Treatment (In Situ)
- Steam Enhanced Extraction
Comments:
Steam was injected into a total of 16 wells at typical rates of 50lbs/hr per well with a total injection rate of between 1,500 and 5,500 lbs/hr. A total of approximately 4 million liters of water was injected as steam. In the same period, 6.5 million liters of water was extracted from the center of the site, ensuring hydraulic control.
The main removal mechanism is TCE DNAPL boiling and vaporization in places heated to temperatures above the in-situ boiling point.
A total of about 830 lbs. of TCE was removed. Drill back revealed that the target layer has been largely remediated, leaving relatively low concentrations behind
This was a pilot test.
The pilot test showed that if operated longer, TCE can be effectively removed even when more than half of the mass is trapped below the permeable aquifer in weathered, fractured shale.
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