LasagnaTM Soil Remediation at the U.S. Department of Energy's Paducah Gaseous Diffusion Plant, Cylinder Drop Test Area, Paducah, Kentucky

Site Name:

U.S. DOE Paducah Gaseous Diffusion

Location:

Paducah, Kentucky

Period of
Operation:

January - May 1995

Cleanup
Type:

Field demonstration

Technical
Information:

Sa V. Ho, Monsanto, (314) 694-5179
Steven C. Meyer, Monsanto, (314) 275-5946
Joseph J. Salvo, GE, (518) 387-6123
Stephen H. Shoemaker, DuPont, (713) 586-2513

Technology:
Integrated in situ technology

- patented technology developed by an industrial consortium consisting of Monsanto, GE, and DuPont
- combines electroosmosis, biodegradation, and physicochemical treatment processes
- electrodes energized by direct current cause water and soluble contaminants to move through treatment layers
- treatment zones decompose or adsorb contaminants
water collected at the cathode is recycled to the anode for acid-base neutralization

Cleanup Authority:
EPA and State of Kentucky

SIC Code:
Not Available
Points of Contact:
Skip Chamberlain, DOE, (301) 903-7248
Dave Biancosino, DOE, (301) 903-7961
Jim Wright, DOE, (803) 725-5608
Kelly Pearce, DOE, (304) 285-5424

Contaminants:
Trichloroethene (TCE)

- TCE concentrations in clay soil ranged from 1 ppb to 1760 ppm
- Average TCE concentration was 83.2
- Highest TCE concentrations (200 - 300 ppm) found 12-16 ft below surface

Waste Source:
Not Available

Type/Quantity of Media Treated:
Soil and soil pore water

- 4 ft layer of gravel and clay overlaying 40 ft layer of sandy clay loam with interbedded sand layers
- low organic content
- 15 ft wide x 10 ft across x 15 ft deep

Purpose/Significance of Application:
Lasagna™ is an in situ technology suited to sites with low permeability soils that combines several technologies to remediate soil and soil pore water contaminated with soluble organic compounds

Regulatory Requirements/Cleanup Goals:
- A cleanup standard for TCE in soil was set at 5.6 ppm.
- No air permits or Underground Injection permits were needed.
- The demonstration was granted a categorical exclusion under the NEPA

Results:
- Treatment reduced TCE concentrations in test zone on average from 72.6 to 1.1 ppm (a 98% reduction)
- An electroosmosis flow rate of 4 L/hr was achieved, and 3 pore volumes of water were transported during a 4-month operating period
- In probable DNAPL locations, TCE was reduced to less than 1 ppm, except for one deep location near an untreated zone that was reduced to 17.4 ppm (diffusion from untreated deep zones suspected)
- Results from the field demonstration were used to develop plans for expanded treatment at Paducah

Cost Factors:
No data are provided on the capital or operating costs for the field demonstration - DuPont analyzed the costs for using Lasagna™ to treat TCE-contaminated clayey soil, and estimated that costs would range from $40 to 90/yd3 of soil for a 1-acre site, ranging from 1-3 years for remediation - Major cost elements include electrode construction; other factors include electrode spacing, placement of electrodes and treatment zones, soil properties, depth of contamination, required purge water volume, cleanup time, and cost of electrical power - DuPont benchmarked unit costs for Lasagna™ compared with other in situ technologies which required more than 30 years to remediate a site (in situ treatment zones using iron filings, pump and treat, in situ aerobic biological treatment, and surfactant flushing) and determined that Lasagna™ is within the range of unit costs for these technologies ($25-75/yd3)

Description:
Lasagna™ is an in situ technology that combines electroosmosis, biodegradation, and physicochemical treatment processes to treat soil and soil pore water contaminated with soluble organic compounds. The technology was developed by an industrial consortium consisting of Monsanto, GE, and DuPont and patents for the technology and the trademark have been granted to Monsanto. The technology is suited for sites with low permeability soils. The process uses electrokinetics to move contaminants in soil pore water into treatment zones where the contaminants can be captured or decomposed.

At the Paducah Gaseous Diffusion Plant, Lasagna™ was demonstrated on a clayey soil contaminated with TCE, with an average concentration of 83 ppm. Treatment reduced TCE concentrations in a test zone from on average 72.6 to 1.1 ppm (a 98% reduction). An electroosmosis flow rate of 4 L/hr was achieved, and 3 pore volumes of water were transported during a 4-month operating period. Results from the field demonstration were used to develop plans for expanded treatment at Paducah (scheduled for June 1996, per report dated April 1996)