Potable Water

Key Stage 4

Potable water is water that is safe to drink.

Potable water can be obtained from fresh water or salt water.

The method to obtain potable water depends on the source.

Fresh water is the easiest to make potable. This is done by filtering the water to remove solid particles then adding Chlorine or using Ultraviolet Light to kill any harmful micro-organisms.

Salt water must have the salt removed first. This can be done by distillation which also kills micro-organisms and purifies the water. However, this is very expensive because it requires heating the water. It can also be done using a process called reverse osmosis in which the salt water is sent through pipes at extremely high pressure. The walls of the pipes are a partially permeable membrane and so the high pressure forces the water through but not the salt.