Evaluation of Soil Venting Application 1
The ability of soil venting to inexpensively remove large amounts of volatile organic compounds (VOCs) from contaminated soils is well established. However, the time required using venting to remediate soils to low contaminant levels often required by state and federal regulators has not been adequately investigated. Most field studies verify the ability of a venting system to circulate air in the subsurface and remove, at least initially, a large mass of VOCs. As venting proceeds, lower molecular weight organic compounds will preferentially volatilize and degrade. Venting circulates air in soils at depths much greater than are possible by tilling, and oxygen transport via the gas phase is much more effective than injecting or flooding soils with oxygen saturated liquid solutions. Minimum depths are recommended by some practitioners for venting operation to avoid short-circuiting of air flow. Optimizing venting performance is critical when attempting to meet stipulated soil-based cleanup levels required by regulators.