This short documentary shows how a city's water supply is purified at a filtration plant. The complex system of the underground mains that supply all parts of the city with water is also illustrated, as is the safeguarding of water supplies on trains, ships and aircrafts.
This short documentary shows how a city's water supply is purified at a filtration plant. The complex system of the underground mains that supply all parts of the city with water is also illustrated, as is the safeguarding of water supplies on trains, ships and aircrafts.