Very low voltage of electricity travels through the ground. The amount of electricity that can be carried by the ground depends on the type of soil. For example, damp hard clay soil has a high conductivity potential and dry coarse sand has virtually no conductivity potential.
Since electricity travels through the ground, if it finds a steel evacuation line, it will use it for whatever distance suits it. When electricity leaves the steel evacuation line, a chemical reaction occurs. This chemical reaction is the underground corrosion, which can be fast or slow depending on the type of soil in the area.
GEA recommends the use of a sacrificial anode on the equipment and at every 120 feet (36.5 m) on steel evacuation line.