Chemical Oxidation for Clean Up of Contaminated Ground Water

Contamination of soil and ground water by organic chemicals is a widespread problem across the U.S. and around the world. At sites where organic chemicals are present in the form of dense nonaqueous phase liquids (DNAPLs), clean up of contaminated ground water has been extremely difficult and costly; conventional ground water pumping and treatment approaches have commonly failed to achieve clean up goals. Major research and development efforts have been directed at finding alternative remedies that can clean up ground water and eliminate risks or reduce them to an acceptable level. Recent efforts have increasingly focused on source zone treatment of DNAPL contamination to reduce the volume and mass of DNAPLs available for dissolution into ground water. A variety of in situ technologies have been developed and demonstrated, including in situ chemical oxidation (ISCO). ISCO involves the delivery of chemical oxidants into the subsurface to destroy organic chemicals (e.g., chlorinated organic solvents or fuels) and thereby remediate a site to a risk-based clean up goal. ISCO can feasibly be implemented alone to treat a contaminant source zone or an associated groundwater plume, or used in combination with other remedial technologies (e.g., after surfactant flushing or before bioremediation).