Effective In-Situ Treatment of a 3,280 Ft. PCE Plume in Finland

Case study highlights:

• PCE concentrations were reduced to below the drinking water limit at the water supply well
• Results indicate that the ERD and PlumeStop approach can be successfully applied in cold groundwater aquifers with low organic carbon content
• Integrated source area/PlumeStop-ERD barrier treatment is an effective strategy for treating elongated chlorinated solvent plumes

In Eastern Finland, a fast-moving PCE (perchloroethene) plume beneath a metal-processing facility was remediated to reduce impacts on a municipal drinking water source. The demonstration project achieved PCE concentration reductions of approximately 80% in the plume within months and 90 to 95% by 18 months, ultimately reducing PCE to below the drinking water limit at the municipal water supply well. The in situ remedy applied enhanced reductive dechlorination (ERD) beneath the source area at the industrial building, combined with downgradient plume area treatment comprising ERD plus adsorption, facilitated by PlumeStop, to form an injectable permeable reactive barrier. The progressive approach uses relatively few injection points to reduce the contaminant flux into the plume and to impede contaminant migration downgradient, resulting in the effective and economical treatment of a 3,280-ft.-long chlorinated solvent plume to mitigate the potential exposure risk.