This site in downtown Chicago, was impacted by chlorinated solvents used in various historic manufacturing activities. DCE and TCE concentrations were recorded up to 7,440 µg/L in a sand formation over clay. As the site was to be redevelopment as a hotel and sports arena, and any programme delays would be extremely costly, the client needed a quick and permanent remedy to achieve the stringent target levels (of: total VOC MCL 567 µg/L and TCE MCL 242 µg/L) REGENESIS successfully remediated the groundwater to below target levels within the tight time window.
The designed volumes of PlumeStop, HRC, and BDI Plus were successfully applied within the defined treatment zones (see map right) during the application event. A combined volume of 265 m3 of PlumeStop, HRC and BDI Plus was injected via 138 direct push injection points.
78 days post-application, the two key validation wells (AW 3-3 and AW 3-2) observed 80% and 97% reduction in total CVOCs. BDI Plus was used to facilitate the bioaugmentation. As a result, the DHC sp. count and functional genes of the anaerobic metabolic pathways increased significantly from baseline measurements, as determined by QuantArray® analysis. This means that not only contaminant sorption is occurring, but that biodegradation is happening as well. The second and third monitoring round (at 108 and 138 days) confirm the production of breakdown products, indicating that enhanced reductive dechlorination (ERD) is ongoing. Regulatory sign-off is applied for.
PlumeStop™ Liquid Activated Carbon™ is composed of very fine particles of activated carbon (1-2μm) suspended in water through the use of unique organic polymer dispersion chemistry. Once in the subsurface, the material behaves as a colloidal biomatrix binding to the aquifer matrix, rapidly removing contaminants from groundwater, and expediting permanent contaminant biodegradation.
HRC® is a controlled release, electron donor material, that when hydrated is specifically designed to produce a controlled release of lactic acid. The newly available lactic acid is critical for the production of hydrogen to fuel anaerobic biodegradation processes in soil and groundwater.
Bio-Dechlor INOCULUM® Plus is an enriched natural microbial consortium containing species of Dehalococcoides sp. (DHC). This microbial consortium has since been enriched to increase its ability to rapidly dechlorinate contaminants during in situ bioremediation processes.