potable water

• What is potable water?

  Water that is safe to drink
• Why is potable water not considered 'pure'?

  It contains dissolved substances
• What must potable water have to be safe?

  Sufficiently low levels of dissolved salts and microbes
• What are the methods used to produce potable water in the UK?

  1. Select an appropriate source of fresh water
  2. Pass water through filter beds to remove solids
  3. Sterilize the water to kill microbes
• What is an appropriate source of fresh water in the UK?

  Rainwater collected in ground/rivers/lakes
• What is the purpose of filter beds in water treatment?

  To remove different sized insoluble solids
• What are the sterilizing agents used for potable water?

  Ozone, UV light, or chlorine
• What is required if only salty or sea water is available?

  Desalination
• What are the methods of desalination?

  1. Distillation
  2. Processes with membranes (e.g., reverse osmosis)
• Why are desalination methods considered very expensive?

  They require advanced technology and resources