A two-year performance evaluation on the longevity of a 90-foot deep Feroxsm Treatment Cell (FTC) was recently completed at a DOD facility in Tennessee. Installation of the FTC was implemented in October 2004 as part of a Remedial Investigation Pilot Study within a suspected source area impacted with elevated concentrations of TCE and 1,1,2,2-PCA. As part of the field application, ARS utilized an innovative injection process combining sonic drilling and our proprietary gas-based injection technique to disperse 25,000 pounds of H-200 ZVI powder via four injection points from a depth of 75 - 90 ft bgs.

Groundwater samples collected within the FTC two years after the installation indicated the continuing reduction of CVOCs by the ZVI. More notably, CVOC levels in a monitoring well situated with the FTC have been reduced from a baseline concentration of 11,000 ppb to Non Detect. In addition, geochemical conditions within the FTC, as demonstrated by such indicators as D.O., ORP, pH and ferrous iron, remain highly reductive as the emplaced iron continues to react and reduce the contaminants.

The two-year evaluation also revealed limited increases in groundwater pH and therefore minimizing the formation of oxide coatings on the iron particles.