Soil Vapor Extraction (SVE) also known as “soil venting” or “vacuum extraction”, is an In-Situ remedial technology that reduces concentrations of volatile constituents in petroleum products adsorbed to soils in the unsaturated (vadose) zone. In this technology, a vacuum is applied through wells near the source of contamination in the soil. Volatile constituents of the contaminant mass “evaporate” and the vapors are drawn toward the extraction wells. Extracted vapor is then treated as necessary (commonly with carbon adsorption) before being released to the atmosphere. The increased air flow through the subsurface can also stimulate biodegradation of some of the contaminants, especially those that are less volatile. Wells may be either vertical or horizontal. In areas of high groundwater levels, water table depression pumps may be required to offset the effect of upwelling induced by the vacuum.

This technology has been proven effective in reducing concentrations of volatile organic compounds (VOCs) and certain semi-volatile organic compounds (SVOCs). SVE is generally more successful when applied to the lighter (more volatile) products such as gasoline and chlorinated hydrocarbons such as PCE. Diesel fuel, heating oils, and kerosene, which are less volatile than gasoline, are not readily removed by SVE alone. Because almost all petroleum products are biodegradable to a certain degree, these heavier petroleum products may be suitable for removal by Bioventing. In-situ heating can be used to enhance the volatility and remediation of these heavier petroleum products (and lighter products) because vapor pressure generally increases with temperature.