Cleaning Soil with Electric Current.

• Position: Brief Article

Industry is warming up to a new way to treat contaminated soil and groundwater, utilizing electricity to heat soil and strip contaminants from the ground. Commercial and industrial sites around the country are using Six-Phase Heating to remove contaminants such as gasoline, chlorinated solvents, and other volatile and semi-volatile compounds from the soil and groundwater quickly and cost-effectively.

"One advantage of Six-Phase Heating is that there is no need to excavate contaminated sites," explains Bill Heath, a senior development engineer at Pacific Northwest National Laboratory, Richland, Wash., who helped develop the technique. The process uses electric current to create heat, raising the temperature until the moisture in a contaminated aquifer boils and turns to steam.

The steam, carrying the stripped contaminants, rises to the surface, where it is captured by extraction wells and treated. Compared to traditional vapor extraction methods, Six-Phase Heating is much less sensitive to the type of soil or how...