The Lasagna Technology for In Situ Soil Remediation. 2. Large Field Test

A full-scale field test of the Lasagna process was conducted at a Department of Energy trichloroethylene-contaminated clay site in Paducah, Kentucky. The test covered an area 21 ft × 30 ft (6.4 m × 9.2 m) and reached 45 ft (13.7 m) deep. A modified sheet piling method was utilized for installing electrodes and treatment zones in thin layers through stiff clay soil without generating solid waste. Iron filings were used in the treatment zones for in situ TCE degradation. Complications encountered during the test included contamination at significantly higher levels than anticipated and complex hydrogeology in the subsurface. Treatment effectiveness seems to vary with location, but in the contaminated areas bracketed by treatment zones, TCE removal ranged from 95% to over 99%. There are strong indications that some of the TCE was transported and degraded in the DNAPL form, which has significant implications. On the basis of the field results, treatment cost for a typical one-acre site with contamination from 15 to 45 ft deep ranges from about $45 to $80/yd3. Implemented in its full configuration for the first time at a real site, the Lasagna process has demonstrated its robustness and cost-effectiveness in cleaning up TCE-contaminated soil in place.