Potable water

• Sources of fresh water

  • Aquifers
  • Lakes
  • Rivers
  • Reservoirs
• Fresh water in rivers already has very low levels of dissolved minerals
• In the UK, chlorine is used to sterilize potable water, while in some parts of the world ozone or ultraviolet light are used
• Producing potable water from fresh water

  1. Use a good source of fresh water

  2. Pass the water through filter beds to remove material such as leaves and suspended particles

  3. Sterilize the water to kill microbes using chlorine
• Potable water


  Water that is safe to drink, with low levels of dissolved salts and microbes
• Producing potable water from salty water

  1. Desalination reduces the levels of dissolved minerals down to an acceptable level for potable water

  2. Desalination methods include distillation and reverse osmosis

  3. Both distillation and reverse osmosis reduce the levels of dissolved minerals, but they require large amounts of energy making them expensive
• Seawater has very high levels of dissolved minerals
• Rainwater provides most of the potable water in the UK
• Desalination


  Reduces the levels of dissolved minerals in salty water to make it potable