U.S. Environmental Protection Agency

Field Applications of in Situ Remediation Technologies: Permeable Reactive Barriers U.S. Environmental Protection Agency

Approximately 85% of the hazardous waste sites in the United States have contaminated ground water. The conventional approach for remediating contaminated ground water has been to extract the contaminated water, treat it above ground, and reinject or discharge the clean water in a process known as "pump-and-treat." The recovered contaminants must be disposed of separately. Pump-andtreat technologies require considerable investment over an extended period of time, and it has been shown that these technologies often do not actually remove the source of the contamination. Current policies and laws stress "permanent" remedies over simple containment methods. Consequently, there is considerable interest in and effort being expended on alternative, innovative treatment technologies for contaminated ground water.