Lab Studies and Site Characterization for Permeable Reactive Barrier Walls
One area of site characterization for reactive barriers that needs further study is microbial activity. The interactions of such native microbial populations, contaminants, and reactive barrier materials are likely to be quite complex, and have the potential for either beneficial or detrimental effects on the remediation. Native microbial consortia are often responsible for natural plume attenuation processes. Other beneficial effects could include enhanced contaminant degradation within the barrier; for example the further reduction in Eh due to the presence of sulfate-reducing bacteria might increase the rates of contaminant reduction. Adverse effects could include the potential loss of permeability of the reactive zone due to biofouling. Additional laboratory and field studies are needed to understand these interactions and learn how to enhance the positive effects and reduce the potential negative effects of native microorganisms.