Remediation of Contaminated Groundwater

In order to decrease the health risk deriving from a contamination event,a number of cleanup and corrective actions, collectively called remediation, can beimplemented. Remediation can be applied directly at the site of contamination (insitu) or off site (ex situ), in which case the contaminated environmental compo-nent is physically extracted and treated in dedicated facilities at the surface. Thereare three main remedial approaches, generally categorized as: containment, whichaims at preventing the migration of the contamination and hence the exposure ofsensitive targets; active restoration, which entails removing or treating the contami-nation; and natural attenuation, which relies on naturally occurring biological, chem-ical and physical degradation or transformation processes that convert contaminantsinto harmless compounds. This Chapter reviews the main containment and remedialstrategies available for the management of a groundwater contamination event, andprovides valuable information to support the choice of the most suitable approach.The presented strategies include: free product recovery for light non-aqueous phaseliquid removal; vacuum enhanced extraction; subsurface containment; pump andtreat; air- and bio-sparging; permeable reactive barriers; in situ flushing; in situ oxi-dation;insitubioremediation.Applicability,designoptionsandoperatingconditions,as well as advantages and drawbacks of the presented methods are illustrated.