Technology:
Lasagna™
- Uses an applied direct current electric field to drive contaminated soil-water, in a process called electro-osmosis, through treatment zones installed in the contaminated soil
- Soil-water flows from the anode electrode toward the cathode electrode, which is located in the center of the treatment zone
- Treatment zones are vertical zones comprised of iron filings and Kaolin clay (60% by weight iron particles in a 40% by weight Kaolin clay)
- Treatment zone slurry was prepared offsite and transported to LasagnaTM site in a concrete mixer truck; slurry was injected using a hollow mandrel
- Contaminants are broken down into nonhazardous components as they come into contact with the iron particles in the treatment zone
- Elevated soil temperature as a result of current flow through soil also contributes to contaminant mobility and destruction
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Cleanup Authority:
Federal Facilities Agreement between DOE, EPA, and the Commonwealth of Kentucky. ROD dated July, 1998.
Contacts:
CDM Federal Programs Corporation
325 Kentucky Avenue
Kevil, KY 42053
(270) 462-3006 (phone)
(270) 462-3060 (fax) |
Contaminants:
TCE |
Waste Source:
Improper disposal of chemicals used as part of cylinder integrity testing processes |
Type/Quantity of Media Treated:
Soil over a 6,480 ft2 area in Solid Waste Management Unit (SWMU) 91 |
Purpose/Significance of Application:
To reduce TCE concentrations in soil to below cleanup levels using the Lasagna™ technology |
Regulatory Requirements/Cleanup Goals:
Risk-based soil TCE cleanup level of 5.6 mg/kg, as specified in ROD |
Results:
Average initial TCE concentration in soil was 84 mg/kg, with a maximum concentration greater than 1,500 mg/kg
- After nine months of operation (August 2000), sampling data showed that average TCE concentration had been reduced to 43.3 mg/kg, with a high of 552 mg/kg
- After 21 months of operation (August 2001), average TCE concentration had been further reduced to less than 1.5 mg/kg, with a high of 27 mg/kg
- Verification sampling in April-May 2002 (after system shutdown) indicated average TCE concentrations of 0.38 mg/kg, with a high of 4.5 mg/kg, less than the cleanup goal of 5.6mg/kg
- GC-MS analysis of select soil samples after system shutdown showed that cis-1,2-dichloroethene and vinyl chloride were either absent or present at very low concentrations |
Cost Factors:
Total cost for full-scale remediation was approximately $4,000,000, broken down as follows:
- 1999: Remedial design, remedial action work plan, mobilization and construction start: $2,510,000.
- 2000: Construction complete, post construction report, operations and maintenance plan and begin operations and maintenance: $906,000 (this includes $785,000 for construction and $121,000 for operations and maintenance)
- 2001: Continue operations and maintenance, interim sampling report A: $263,000.
- 2002: Interim sampling report B, complete operations and maintenance period, verification sampling and analysis plan, remedial action report: $279,000
There were no regulatory agency oversight costs associated with the project. |
Description:
SWMU 91 at the PGDP Superfund site in Paducah, Kentucky was used as part of cylinder integrity testing processes from late 1964 until early 1965 and in February 1979. Before the cylinders were tested, they were chilled in a pit containing TCE and dry ice. The TCE was not removed from the pit after the tests, eventually causing contamination of the surrounding soil and groundwater. This report describes activities under one phase of the cleanup, which covered soil contaminated with TCE. Full-scale operation of LasagnaTM began at the site in December 1999 under a Federal Facilities Agreement, and continued for two years until December 2001.
The technology application involved inducing electro-osmosis in the soil using an applied direct current electric field. The soil water was driven to treatment zones consisting of iron filings and Kaolin clay, where TCE was degraded to nonhazardous compounds. The average initial soil concentration of TCE was 84 mg/kg, with a maximum concentration greater than 1,500 mg/kg. The ROD specified a cleanup level of 5.6 mg/kg. After 21 months of operation, average TCE concentrations had been reduced to less than 1.5 mg/kg, with a high of 27 mg/kg. Verification sampling after system shutdown indicated average TCE concentrations of 0.38 mg/kg, with a high of 4.5 mg/kg, thereby meeting the cleanup goal. The total cost for the remediation was approximately $4,000,000, including capital costs, construction, mobilization, and operation and maintenance costs.
During the first two treatment zone installation attempts, the treatment material would not drop out of the mandrel as the mandrel was vibrated out of the ground. It was determined that too many large particles existed in the iron aggregate thereby impeding flow. To address this, the manufacturer re-supplied the treatment material with a smaller grain size to address this. A cost-saving measure implemented during the project was monitoring the system remotely using a data acquisition system, which also had shutdown capabilities for fault conditions. |
