In this deck, we'll explore the vital topic of water. You'll learn how we get safe drinking water, what the difference is between potable and pure water, and how we treat waste water to protect the environment. We will also cover the required practical for analysing and purifying water samples.

Let's start with a key definition. Water that is safe to drink is called potable water. It's important to understand that potable water is not the same as pure water. Pure water contains only water molecules, H two O, and nothing else. Potable water, on the other hand, can and usually does contain dissolved substances, like salts and minerals. The crucial thing is that the levels of these dissolved substances, and any microbes, are low enough not to be harmful.

Most of the potable water in the UK comes from fresh water sources like rivers, lakes, and reservoirs. However, this water needs to be treated before it's safe to drink. The treatment process involves two main stages: filtration and sterilisation.