The two most commonly used in situ thermal technologies are Thermal Conductive Heating (TCH) and Electrical Resistance Heating (ERH). Energy is delivered based on the subsurface thermal conductivity and electrical resistivity. Most sites must be heated to 100C before the remedial goals are met.
The energy delivery by TCH and ERH is typically in the range of 250-1,000 W/ft of heater or electrode (800- 3,000 W/m).
Flowing water can carry energy away much faster than that. The flow of groundwater will also cool geological layers located above and below the flowing groundwater.
If groundwater cannot be slowed down by controlling influx via pumping or a physical barrier, other options need to be considered. In these types of situations, the Steam Enhanced Extraction (SEE) technology is the answer.
