Electrical Resistance Heating (ERH) also known as  “Six Phase Heating”, is an In-Situ remedial technology that reduces concentrations of volatile constituents adsorbed to soils in the unsaturated (vadose) zone or to volatile constituents in groundwater, dissolved or in Dense Non Aqueous Phase Liquid (DNAPL) or even Light Non-Aqueous Phase Liquid (LNAPL). In this technology, electrical current is passed through the subsurface soil or groundwater by use of installed electrodes. The natural resistance to electrical current flow provided by the soil creates heat (similar to a toaster oven). This manner of In-Situ heating allows the energy to more effectively focused and efficiently delivered to the treatment volume. The subsurface volume is heated to approximately 100 degrees Celsius and in the process volatile constituents of the contaminant mass “Evaporate” or Boil Off into the Atmosphere.

This technology has been proven effective in reducing concentrations of Volatile Organic Compounds (VOCs) and Semi-Volatile Organic Compounds (SVOCs). Although a relatively new technology more than 60 sites have completed remediation using this technology and the number is growing rapidly. Electrical Resistance Heating is generally more successful when applied to the lighter (more volatile) products such as gasoline and chlorinated hydrocarbons such as PCE. However, significant success has been obtained for such constituents as diesel fuel, heating oils, and kerosene, which are less volatile than gasoline. It has been proven that significant biological stimulation occurs with the application of this technology therefore opening up a wide range of applications.
Unfortunately one of the main draw-backs is that it requires and consumes large quantities of Electricity and Vents the Contaminents into the Atmosphere.