Understand that water of appropriate quality is essential for life and that human drinking water must have sufficiently low levels of dissolved salts and microbes.
Define potable water as water that is safe to drink, recognising that it is not pure water in a chemical sense due to the presence of dissolved substances.
Explain that the methods used to produce potable water depend heavily on the available water supplies and specific local conditions.
Describe how rain provides fresh water with low levels of dissolved substances that collects in the ground, lakes, and rivers, particularly in the United Kingdom (UK).
Outline the standard process for producing potable water from fresh water, including choosing an appropriate source, passing the water through filter beds, and sterilising.
Identify common sterilising agents used for potable water treatment, including chlorine, ozone, or ultraviolet light.
Explain the necessity of desalination processes for salty water or sea water when fresh water supplies are limited.
Describe methods of desalination, such as distillation and membrane processes like reverse osmosis, and note their requirement for large amounts of energy.
Distinguish clearly between the concepts of potable water and pure water.
Describe the differences in the required treatment processes for ground water versus salty water.
Provide clear scientific reasons for each of the steps used in the production of potable water.
Analyse and purify water samples from different sources practically, including testing pH, checking for dissolved solids, and performing distillation.
