The Use of Permeable Reactive Barriers for In-situ Remediation of

The treatment of contaminated groundwater is among the most difficult and expensive environmental problems and often the primary factor limiting closure of contaminated sites. The most common technology used historically for remediation of groundwater has been ex-situ pump-and-treat systems. Pump and treat systems are still suited for certain site-specific remediation scenarios; however, the limitations of pump-and-treat technologies have also been recognized. This has been accompanied by the recognition for the need for new innovative solutions for the treatment of contaminated groundwater. Over the past decade, permeable reactive barriers (PRBs) have provided an increasingly important role in the passive interception and in situ treatment of groundwater as a component of remedial action programs. PRBs have been used to remove a wide range of organic and inorganic contaminants from groundwater including petroleum hydrocarbons, chlorinated solvents, nutrients, metals and radionuclides. The concept of PRBs is relatively simple. A reactive material is placed in the subsurface at a location that intercepts a groundwater contaminant plume, such as a deep backfille