Case Studies - NJ004 - Feroxsm

Manufacturing Facility - New Jersey

The Feroxsm process was applied at a former manufacturing facility located in Totowa, New Jersey. The remedial action was implemented under the NJDEP ISRA program initiated by the cessation of operations at the facility

The project scope consisted of the installation of a 170-foot long by 20-foot wide Feroxsm Treatment Zone at the downgradient boundary of the site. The system was designed to reduce TCE in both adsorbed and dissolved phases in the shallow aquifer. TCE concentrations were as high as 11,600 µg/L in the groundwater. The shallow geology at the site consists of highly permeable zones of silty and fine to medium sand interbedded between clay lenses. The layout of the Treatment Zone is shown below.

As-built layout of the Feroxsm Treatment Zone and sampling locations.
The table right shows the results of the baseline and post-injection groundwater sampling.

Utilizing a direct-push injection nozzle system, 4,200 pounds of a special formulation zero-valent iron (ZVI) powder were injected into the formation. The injection nozzle was advanced by a vibratory drilling technique to the design depths.

During injections, the FeroxSM material was observed at adjacent monitoring wells more than 20 feet away. Under injection pressures ranging from 80psi to 250 psi, the Feroxsm powder was intermixed with the permeable sand by fluidizing the matrix within two discrete intervals starting at 5 feet and terminating at 20 feet below the surface.


Feroxsm injections are applied using a direct push drill rig, which vibrated the injection nozzle to depth.

Outcome

Based on field observations, the injection process was a success in effectively dispersing the Feroxsm powder into the targeted zone. A data summary table on the following page presents the results of the baseline and post-injection sampling. Post-injection 1 shows an increase in CVOC concentrations in most of the monitoring wells. These temporary increases are commonly observed as the injection process makes connections with hydraulically isolated zones within the formation where residual contamination is located. The data shows evidence of dechlorination of the TCE. As TCE concentrations decreased after the first post-injection event, concentrations of cis-1,2-DCE, TCE's sequential dechlorination daughter product, showed significant increases.

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