Shallow groundwater at the site became contaminated due to the leaks of a chromium plating factory operating since 1950s. Groundwater monitoring since 2008 has shown a plume extending downgradient the source area and, in 2011, the in situ P&T system shown an asymptotic Cr(VI) concentration trend. In addition, Hexavalent Chromium concentrations and geochemical sampling data indicated that no natural attenuation was occurring. In early 2012, an application of Metals Remediation Compound (MRC) and 3-D Microemulsion® (3DMe) was performed in the main contaminated area through 10 fixed wells as first step of a full scale design to evaluate the efficacy of the treatment reagents in the aerobic aquifer.

An overview of the remediation approach, results from monitoring actions and field studies will be presented. Measurements of stable Cr(III) in groundwater samples along with the field parameters demonstrated the reagent distribution in the contaminated area and the on-going geochemical reduction of Cr(VI).