Current and future bioremediation applications: Bioremediation from a practical and regulatory perspective

Abstract

Chlorinated solvents have been a primary focus of the remediation industry since the 1980s, and many remedial technologies have been developed, tested, and applied to remove these constituents from contaminated aquifers. The relative ease of stimulating organohalide-respiring bacteria in situ and the availability of low cost electron donor substrates and effective bioaugmentation cultures have allowed in situ bioremediation technologies to be applied successfully at thousands of sites around the world. Typically, the success of the remediation is dependent more on the site characteristics (e.g., geochemistry, geology, hydrology, contaminant concentration, etc.) than the fidelity of the microbes. As we begin to address the most challenging contaminated sites that remain to be remediated, including those with free product contamination, complicated geologies (e.g., low permeability soils or fractured rock), or complex contaminant mixtures, in situ bioremediation may not be the sole technology applied at these sites but it will likely be an important component of many remedies. Therefore, fundamental understandings of microbiology and the development of novel application approaches remain essential to ensure continued success in remediation of the most difficult chlorinated solvent-contaminated sites.