*Weaknesses of ERH include heat losses on small sites.  Treatment volumes that have a large surface area but are thin with respect to depth will have significant heat losses which makes ERH less efficient.  The minimum treatment interval for efficient ERH remediation is approximately 10 vertical feet.
*Co-contaminants like oil or grease make remediation more difficult.  Oil and grease cause a Raoult’s Law effect which requires more energy to remove the contaminants.
*Peat or high organic carbon in the subsurface will preferentially adsorb VOCs due to van der Waals forces.  This preferential adsorption will increase the amount of energy required to remove the VOCs from the subsurface.
*Fuel sites are less-commonly treated by ERH because other less-expensive remediation technologies are available and because fuel sites are usually thin (resulting in significant heat losses).
*Sites within landfills are also challenging because metallic debris can distort the electric current paths. ERH is more uniform in natural soil or rock.