Case Studies - NJ012 - Liquid Atomized Injection of EHC at Industrial Site

Central New Jersey

Liquid Atomized Injection (LAI) 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, 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 LAI.

Seven hydraulic and four LAI injection points were used to inject 8,500 pounds of EHC™ as a 30% slurry over the source zone area of 2,400 square feet. 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 feet away from the LAI injection points. The results confirmed that the LAI technique enhanced the amendment distribution and increased the extent of influence significantly compared to hydraulic injection. The use of LAI resulted in significant cost savings for the remedial program, while effectively delivering the amendment within the impacted zone.

 

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