A variety of soil/vapor extraction devices have been installed at contaminated properties for site remediation purposes. These devices are most often used to mitigate gasoline spills but can also be effective for a wide range of volatile organic solvents. The equipment usually consists of a blower with air extraction wells vented to an activated carbon filter. On some sites, the activated carbon may be replaced with a thermal oxidizer, catalytic oxidizer, scrubber, or passive vent. In nearly all instances, the basic operating principle involves the passing of clean air through the contaminated soil to remove a volatile contaminant.