Blackstone Environmental was retained to perform an environmental evaluation of a decommissioned metal plating facility. Intrusive sampling and testing revealed hexavalent chromium impact to soil, with a minor component of volatile organic carbon (trichloroethylene) impact to soil. Blackstone conducted additional exploration to evaluate the extent of impact and to characterize site hydrogeology. Potential viable remediation strategies were evaluated through bench and pilot-scale testing.
The depth of the impact limited the ability to physically remove contaminated media for treatment. The selected remedial alternative involved in-situ chemical fixation by amending impacted soil with calcium polysulfide which would reduce the very mobile and toxic hexavalent form of chromium to the stable, much less toxic trivalent chromium. The in-situ chemical fixation approach is innovative and provides a significant cost savings for the client compared to conventional remediation technologies.