United States
Environmental Protection
Solid Waste and
Emergency Response
April 1999
Cooking  Up  Solutions
Cleaning  Up  With
      People in Paducah, Kentucky are not
      necessarily talking about pasta when
      they brag about their Lasagna™.
Named after the subsurface layering of sands,
silts, and clays, Lasagna™ is an innovative
technology that reduces trichloroethene (TCE)
contamination in soil in a manner that is
faster, more effective, and less costly than
traditional cleanup options.

At the Paducah Gaseous Diffusion Plant, a
U.S. Department of Energy (DOE) facility in
western Kentucky, a partnership of federal
agencies, private industry, and the
Commonwealth of Kentucky tested Lasagna™
in dense, clayey soil. This innovative
technology was used to help eliminate source
contamination of TCE from the soils and to
prevent associated underlying groundwater
contamination. Lasagna™ represents an outstanding achievement by business and
government in joint pursuit of solutions to one of the nation's most complex
cleanup problems.

"We see this as an innovative technology that can knock out contamination.
That's why we're excited about it," says Carl  Froede, Remedial Project Manager
for the Environmental Protection Agency's Region 4. "Using Lasagna™ makes it
possible to remediate a site in two to four years as opposed to potentially
hundreds of years with conventional technologies."

Problematic Ingredients
Since 1952, the Paducah plant has enriched
uranium, a step in making fuel for commercial
nuclear reactors. Located a few miles south of
the Ohio River, an extensive wildlife
management area buffers the plant from the
surrounding community. When tests showed
TCE contamination in four private wells
outside the plant boundary in August 1988,
response was immediate. The discovery of
TCE-contaminated groundwater outside plant
boundaries revealed that TCE, dissolved in
groundwater, had migrated to some nearby
residents' water wells.
DOE acted swiftly to address the situation and halt any
potential health concerns linked to TCE exposure (e.g.,
speech and hearing impairments, kidney disease, blood
disorders, strokes, anemia, diabetes, and skin rashes).
Without delay, DOE installed water lines to nearby
residences and businesses to provide an alternative
drinking water supply, and the Paducah plant continues
to provide drinking water to the affected local  public.
Working with EPA and the Kentucky Department for
 Sampling of activated carbon socks measures
 removal of TCE from contaminated soil.
                                                      Environmental Protection (KDEP), DOE began a
                                                      comprehensive facility-wide search for the sources of TCE

                                                      One area at the plant where TCE contamination is a
                                                      problem is Solid Waste Management Unit 91 (SWMU
                                                      91). In the mid 1960s and late 1970s, transportation
                                                      accidents had been simulated to test the structural
                                                      integrity of steel containers used to transport uranium
                                                      material. DOE tested tanks at SWMU 91, dropping

     Drilling a well point at the Lasagna  test site.
cylinders chilled in dry ice and TCE onto concrete pads. It
has since been determined that the TCE not only splashed
across this area, but also that the original concrete in-ground
pit contained a hole that allowed TCE to leak into the
underlying soil. In addition, Paducah plant workers used
TCE extensively at other locations as a cleaning solvent for
mechanical parts,  a typical industrial practice at that time.
This contamination resulted in the Paducah plant's
placement on the  National Priorities List in 1994.

Combine Partnerships With
The Paducah plant, faced with TCE-contaminated soil and
the need to protect the underlying groundwater aquifers,
exemplified the need for creative solutions. Cleanup
procedures needed to address both soil contamination as a
source of TCE and groundwater contamination resulting
from dissolved TCE. Removing TCE from the soil, as a first
step, would help alleviate  contamination of groundwater by
eliminating its source.  To  clean the clayey soils, however,
DOE needed a valid technology that could remove  the
TCE. One traditional  option was to dig up contaminated
soil and burn away the TCE. Another was  to haul the soil to
a remote location. DOE,  EPA, and KDEP sought a more
innovative solution that would address sitewide
contamination in  ways that reduced toxicity, mobility, and
the volume of waste. Unfortunately, available proven
technologies for treating TCE-contaminated soils were
limited in scope and effectiveness.

In the private sector, corporations also faced the reality of
contamination at their industrial sites. A few corporations
with sufficient resources initiated independent research on
new technologies for environmental cleanup. At the same
time, government regulators determined many cleanup
operations were charting new territory and existing
procedures did not always address the complex problems of
contaminated sites. The number of cleanup projects
nationwide provided an impetus to compare findings among
industry and government researchers to determine the least
expensive and most effective solutions. Both industry and
government stood to benefit from better, faster, and less
costly solutions. A 1992 initiative by the Monsanto
Company led the way. Three U.S.  corporations—
Monsanto, Dupont, and General Electric—created a
research consortium and allied with DOE, KDEP, and EPA
to test Lasagna™ at the SWMU 91 site.

All in Good Measure
The Lasagna™ process targeted the challenge officials faced
at Paducah: removal of TCE from dense, clayey soil more
effectively and more economically than traditional
technologies. Determining remediation for a site requires

that managers identify and review cleanup alternatives,
prepare a feasibility study that analyzes each option, and
determine site-specific applicability of the technologies.
For cleanup at Paducah, Lasagna™ showed promise but,
as an emerging technology, lacked cost and performance
data for onsite remediation of soil contamination. DOE
chose to fund field testing of Lasagna™ at the Paducah
plant in  1995 to determine Lasagna's effectiveness under
actual conditions.

In a joint effort, representatives from DOE, EPA
Region 4, KDEP, and industry (led by Monsanto)
agreed to use Lasagna™ in a phased approach to
determine if it might prove successful. This technology
uses an electric current to drive groundwater through
treatment zones of activated carbon and iron-filings for
the destruction and removal of TCE from soil. The
electric field is reversed to flush the area with water and
remove TCE bound within clayey soil.

Initial tests began in 1995 at a 150-square-foot area at
SWMU  91- The testing during Phase I lasted for 120
days and yielded impressive results—approximately 98
percent of the total  volume of TCE was removed from
the soil. On the basis of that success, year-long testing
was initiated to evaluate performance  and costs at an
expanded site. Completed in July 1997, the expanded
field testing, Phase IIA, which occupied a 20-by-30-foot
area to a depth of 45 feet, showed 75  percent of total
volume of TCE removed from the soil.
A Community Is Served
With outstanding results from the field tests, decision-
makers at the Paducah plant ruled out other more
costly and time-consuming cleanup options for
SWMU 91. Lasagna™'s effectiveness and  comparatively
modest cost estimates established the technology as
workable  and appropriate for remedial action at
SWMU 91. With approval from the Commonwealth
of Kentucky and the Site-Specific Advisory Board,
EPA and DOE signed a Record of Decision in August
1998, documenting Lasagna™ as a viable technology for
removal of TCE from clayey soil.

The success of Lasagna™ shows great promise in
remediating the SWMU 91 site in a better, faster, and
cheaper manner. The full-scale use of this technology at
SWMU 91 will ultimately save more than a million
dollars compared to conventional technology. As cost and
performance projections for full-scale implementation are
verified, Lasagna™ technology moves one step closer to
acceptance as an established treatment for soil
remediation. When established, Lasagna™ can be readily
applied wherever TCE-type chlorinated solvents
necessitate cleanup in clay or silt soils.

The Paducah experiment demonstrates success on several
fronts. Lasagna™'s test results show that the new
technology destroys TCE bound within the clayey soils of
the test site. The partnership's collaboration in treating soil
contaminated with TCE demonstrates that government
and industry can work together effectively in finding
solutions for the remediation of environmental pollution.
The Lasagna™ demonstration also is an opportunity for
the public and private sectors to develop lasting
partnerships with an enormous potential  for meeting
future environmental challenges.
                                                         Solid Waste Management Unit 91, where the Lasagna  technology will be
                                                         applied at full scale.

                                                                    System in
    The Lasagna™ process uses low-voltage electric current to
    clean TCE (a soluble chlorinated solvent) from soil by         v-	_
    flushing contaminated groundwater from the pore spaces
within the silt and clay soils where it may be trapped. Its
capacity to  remove contaminants without excavating, soil
washing, or incinerating the soil is a critical factor in saving
time and money.
                                                      View of Lasagna
Lasagna™ takes its name from the layering of sands, silts, and   operation.
clays, which resembles lasagna in cross-section. Treatment layers
of kaolin and iron filings are interspersed within the contaminated soil. Selected wells surrounding
the project area are filled with carbon or graphite and are used to conduct electricity and generate
the electric field.

When electricity is applied to the carbon or graphite zones, they act as electrodes, creating an
electric field. Within the field, water in the soil flows toward an electrical charge, pulling soluble
contaminants into treatment zones, where they are neutralized or destroyed. A water management
system recycles and returns water that accumulates at the negative pole back to the  positive pole
for acid-base neutralization.

The cost of  cleaning a cubic yard of soil in this way is estimated to be $80 to $190, considerably
less than alternatives that require removal of soil or water. Costs can be reduced by at least
30 percent, for example, compared with deep soil  mixing at $290 per cubic yard.
                      Lasagna™ Technology
                         Applied Electrical Potential

ground surface



        Note: electro-osmotic flow is reversed upon switching electrical polarity.

                           For more information about Lasagna7
         technology and cleanup at the Paducah  Gaseous Diffusion Plant, contact:
             Leon Duquella
             U.S. Department of Energy
             55 Jefferson Circle
             Oak Ridge, TN 37831
             423 576-9649

             Carl R. Froede Jr., P.G.
             Federal Facilities Branch
             Waste Management Division
             U.S. Environmental
             Protection Agency
             Region 4
             Atlanta Federal Center
             10th Floor
             61 Forsyth Street, SW.
             Atlanta, GA 30303-8960
             404 562-8550
Myrna Espinosa Redfield
U.S. Department of Energy
P.O. Box 1410
Paducah, KY 42001

Tuss Taylor
Division  of Waste Management
Kentucky Department for
Environmental Protection
14 Reilly Road
Frankfort, KY 40602
502 564-6716

Please contact the Federal Facilities
Restoration and Reuse Office at 202
260-9924 for copies of this fact sheet
or view the fact sheet on the Internet
by visiting.
   United States
   Environmental Protection Agency
   Washington, DC 20460
     Federal Cleanups That
        Put Citizens First