540/R-07/005

Xpert Design and Diagnostic's (XDD)potassium permanganate in situ chemical oxidation (ISCO) process was evaluated under the EPA Superfund Innovative Technology Evaluation (SITE) Program at the former MEC Building site located in Hudson, New Hampshire. At this site, both soil and groundwater 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, occurring between 6 and 25 feet (1.8 to 7.6 m) below land surface (bls) and within an approximate 1,200 ft² (111.5 m² ) area, were targeted for ISCO treatment. Little [320 lb (145 kg)] potassium permanganate was able to be injected into the shallow, gravelly sandy zone, whereas 1,500 lbs (680 kg) and 1860 lbs (845 kg) were injected into the intermediate peat and deep, silty sand layers, respectively. The average soil concentrations of PCE decreased by 96 percent and 88.5 percent, in the peat and deep layers, respectively. The average soil TCE concentrations decreased by 92 and 98 percent, in the peat and deep layers, respectively. However, cDCE exhibited a no change (+1 percent) and strong increase (+2,570 percent) in the peat and deep layers. The average final ground water concentrations were 746, 612, and 3,090 µg/L PCE, TCE and cDCE, respectively, which were below the 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