Potable water

• Water you can drink
• Not pure, pure water only contains H2O molecules where potable water contains dissolved substances
• Levels if dissolved salts arent too high and has a PH of 7 aren’t any nasties
• rainwater Is a type of fresh water
• When it rains water can either be collected as surface water (rivers lakes) or underground water (rocks that trap water)
• Still needs to be treated to be safe

  • filitration- wa wire mesh screens out large twigs then cracks and sand beds
  • sterilisation- kills any harmful bacteria or microbes
• Some dry countries but enough surface or ground water so seawater used and treated
• Distillation used to desalinate seawater
• seawater can also be treated through processes that use membranes like reverse osmosis
• Both distillation and osmosis are expensive and need loads of energy