When a fault occurs at a high-voltage electrical facility, large amounts of current flow into the earth through the grounding system. This current creates voltage gradients in the soil that can be hazardous to personnel in the vicinity of the fault. Step voltage is the voltage between two points on the earth's surface separated by one pace (approximately one meter), in the direction of maximum potential gradient. Touch voltage is the voltage between a grounded metallic structure and the surface of the earth at the point where a person is standing while touching the structure.