The cleanup of environmental pollution involves a variety of techniques, ranging from simple biological processes to advanced engineering technologies. Cleanup activities may address a wide range of contaminants, from common industrial chemicals such as petroleum products and solvents, agricultural chemicals and metals, to radionuclides. Cleanup technologies may be specific to the contaminant (or contaminant class) and to the site. This entry addresses the cleanup of contaminated soil and water. Air pollution is addressed generally at the point of release by control technologies, because the opportunities to capture and recover airborne contaminants are limited once they are released into the atmosphere.

Cleanup costs can vary dramatically depending on the contaminants, the media affected, and the size of the contaminated area. Much of the remediation to date has been in response to such historical chemical management practices as dumping, poor storage, and uncontrolled release or spillage. Greater effort in recent...