Abstract

Xpert Design and Diagnostics' potassium permanganate in situ chemical oxidation (ISCO) process was evaluated under the EPA's Superfund Innovative Technology Evaluation program at the former MEC building site in Hudson, New Hampshire. At this site, both soil and ground water are contaminated with chlorinated volatile organic compounds (VOCs). The VOCs are primarily perchloroethylene (PCE), trichloroethylene (TCE), and cis-1,2-dichloroethylene (cDCE).

Three saturated stratigraphic zones were targeted for ISCO treatment. The zones were between 6 and 25 feet (1.8 and 7.6 meters) below land surface and were in a 1,200-square-foot (111.5-square-meter) area.

Only 320 pounds (lbs) (145 kilograms [kg]) of potassium permanganate could be injected into the shallow, sandy zone, but 1,500 lbs (680 kg) were injected into the intermediate peat layer and 1,860 lbs (845 kg) were injected into the deep, silty, sand layer.

The average soil concentrations of PCE decreased by 96 percent in the peat layer and by 88.5 percent in the deep layer. The average soil TCE concentrations decreased by 92 percent in the peat layers and by 98 percent in the deep layer. However, cDCE exhibited almost no change (1 percent) and an increase (2,570 percent) in the peat and deep layers, respectively.

The average final ground water concentrations were 746, 612, and 3,090 micrograms per liter (µg/L) of PCE, TCE and cDCE, respectively. These concentrations were below the respective site-specific remediation performance standards of 750, 5,500, 17,500 µg/L. No chlorinated ethylenes were measurable in samples with visible potassium permanganate, but potassium permanganate was not evenly injected into the target formation.

Contact

Michelle Simon

See Also

Superfund Innovative Technology Evaluation

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