Earth potential rise (EPR), also called ground potential rise (GPR), happens when a large fault current from a substation or power line flows into the earth through a grounding grid, causing the ground voltage to spike at the injection point and decrease with distance. This creates hazardous potential gradients, which can injure people through step voltage (between a person's feet), touch voltage (between a metal object and a person's feet), or mesh voltage (within a grounding grid). The danger isn't confined to the substation, as any connected conductive object—like telephone wires, fences, or pipes—can carry this transferred potential far away, posing risks to people and equipment. The severity of an EPR event depends on factors such as the available fault current, soil type and moisture, and the time it takes to clear the fault. To mitigate these risks, engineers conduct fault analyses and implement protective measures like equipotential zones (using metal mats), insulating equipment, and restricted work areas to keep step and touch voltages safe.