Both soil vapor extraction, or “SVE,” and air sparging extract (remove) contaminant vapors from below ground for treatment above ground. Vapors are the gases that form when chemicals evaporate. SVE extracts vapors from the soil above the water table by applying a vacuum to pull the vapors out. Air sparging, on the other hand, pumps air underground to help extract vapors from groundwater and wet soil found beneath the water table. The addition of air makes the chemicals evaporate faster, which makes them easier to extract with another technology, such as SVE. SVE and air sparging are often used together. Both methods are used for chemicals that evaporate easily─like those found in solvents and gasoline. These chemicals are known as “volatile organic compounds,” or “VOCs.”