Produces potable water.

Chlorine is added to kill germs.

The main product of this plant is called effluent.

Baby wipes have to be removed before the water can be treated.

Water from rivers or lakes enters the treatment plant.

Water is allowed to settle in large sedimentation tanks. Sludge sinks to the bottom and is tapped off.

Bacteria are encouraged to grow, so that they can break down nitogenous waste and kill harmful microrganisms.

Bacteria are killed by adding chlorine or ozone.

Water is passed through beds of sand to filter it.

A coagulant is added to clarify the water.

Water from this plant is pumped to homes, schools and offices.

Sludge can be pressed and dried to make a crusty, solid 'cake'.

Biogas can be given off as a by-product.

Living next door to one of these treatment plants would be unpleasant because they can be smelly.

Flocculation - a process where small particles of dirt stick together - occurs before filtration.

The water has no smell or taste when it leaves the plant.

This is a treatment plant for waste water.

Water stays in this treatment plant for over a month.

Which plant produces the purest water?

This shows water being irradiated with UV light

This shows three sedimentation tanks.