Potable Water

• What is potable water?

  Potable water is water that has been treated or is naturally safe for humans to drink.
• How does the definition of pure water differ from that of potable water?

  Pure water only contains H₂O molecules, while potable water can contain other dissolved substances.
• What are the acceptable levels of dissolved salts in potable water?

  The levels of dissolved salts in potable water should not be too high and should be between 6.5 and 8.5.
• What types of harmful substances should be absent in potable water?

  Potable water should not contain harmful bacteria or other microbes.
• What is fresh water?

  Fresh water is water that doesn't have much dissolved in it.
• How can rainwater be collected?

  Rainwater can collect as surface water or as groundwater.
• What are the two forms of water collection from rain?

  Surface water and groundwater.
• What is the primary source of fresh water in the UK?

  The source of fresh water in the UK depends on location, with surface water in warm areas and groundwater in others.
• Why does fresh water need to be treated before use?

  Fresh water needs to be treated to make it safe before it can be used.
• What are the steps involved in treating fresh water to make it potable?

  1. Filtration: Wire mesh screens out large twigs, followed by gravel and sand beds filtering out solid bits.

  2. Sterilisation: Kills harmful bacteria or microbes using chlorine gas, ozone, or ultraviolet light.
• What is desalination?

  Desalination is the process of treating seawater to provide potable water.
• How can seawater be desalinated?

  Seawater can be desalinated using distillation.
• What laboratory method can be used to test and purify a sample of water?

  Distillation can be used to test and purify a sample of water.
• What chemicals can be added to water supplies for health benefits?

  Chemicals such as fluoride can be added to water supplies for dental health.
• Why might some people not be given fluoride in their water supply?

  Some people might not be given fluoride due to health concerns or personal choice.
• What factors influence the production of potable water?

  • Local conditions
  • Availability of surface and groundwater
  • Treatment processes used