NJ012 – Atomized Liquid Injection of EHC
Industrial Site, Central New Jersey
Atomized Liquid Injection (ALI) was used to optimize the amendment delivery and increase the extent of influence for enhanced in situ bioremediation of a source zone within a chlorinated ethene-impacted, shallow unconfined aquifer at an industrial site in Middlesex County, New Jersey. Both the unsaturated and saturated soils and groundwater were impacted by PCE and TCE in the source zone. EHC™, a patented combination of controlled-release carbon and Zero-Valent Iron (ZVI), was selected as the bioremediation amendment due to the high contaminant concentrations and amenable site conditions. A field pilot test was designed and implemented to comparatively evaluate the spatial distribution of EHC™ by conventional hydraulic injection and enhanced injection with ALI.
Seven (7) hydraulic and four (4) ALI injection points were used to inject 8,500 lbs. of EHC™ as a 30% slurry over the 2,400 ft. source zone area. Pressure influence, changes in geochemical conditions and visual observations at nearby groundwater monitoring wells were used to evaluate the spatial distribution and extent of influence of both delivery techniques. Pressure influence was consistently observed 25 ft. away from the ALI injection points. The results confirmed that the ALI technique enhanced the amendment distribution and increased the extent of influence significantly compared to hydraulic injection. The use of ALI resulted in significant cost savings for the remedial program, while effectively delivering the amendment within the impacted zone.