A Permeable Reactive Barrier (PRB) is a treatment zone of reactive material that is built below ground to clean up polluted groundwater. The reactive zone may be installed as a wall to intercept a migrating plume of contaminated groundwater. Alternatively, the contamination can be funnelled by low permeability barriers (e.g. slurry walls) to a gate or vessel containing the reactive media – funnel and gate method.
The reactive media is selected to absorb or adsorb the pollutants from the groundwater or to convert harmful chemicals to harmless by-products. Typical examples of reactive media are:
Cleaning groundwater with a PRB may take many years. The time taken depends on the amount of pollution present in the groundwater and how fast the groundwater moves through the PRB.
There are several advantages of using a PRB to remediate contaminated groundwater:
PRBs have been installed at more than 80 sites.