Insitu source area bioremediation (Sabre) is a potential new weapon in dealing with chlorinated solvents. By Phil Studds, White Young Green Environmental, and Lawrence Houlden, Archon Environmental Consultants. This paper was first published in GE’s June 2006 issue.
Chlorinated solvents have been used in large quantities by a diverse range of industries, including chemicals production, metalworking, automotive, aerospace, electronics and dry cleaning. They account for about 30% of groundwater pollution incidents in England and Wales. Trichloroethene (TCE) is reported to be the most frequent contaminant within this group.
In the subsurface, all except very small releases may result in dense non-aqueous phase liquid (DNAPL) contaminant source areas, which will persist for decades and act as long-term sources of groundwater contamination - 7l of TCE can contaminate 100M.l of groundwater to 100μg/l. Current methods of remediation are usually very expensive, with uncertain results.