Water Purification

Test your knowledge with free interactive questions on Seneca — used by over 10 million students.

Potable Water

We need to drink water to stay alive. However, water is often found with other substances dissolved in it. These substances can be harmful so we treat water to make it potable (safe for human consumption).

Reduce concentrations of microbes

To make water potable, we need to drastically reduce the number of microbes found in it.

Reduce concentrations of dissolved minerals and salts

To make water potable, we need to reduce the concentrations of dissolved minerals and salts found in the water.
We do not eradicate the minerals and salts from the water completely.

Not chemically pure

If water is potable, it does not mean that it has to be chemically pure (made up solely of H₂O molecules).

Potable Water in the UK

There are different methods for producing potable water. Which method is chosen depends on what water is available and the local conditions.

Rainfall

In the United Kingdom, levels of rainfall are quite high.
Rain water is a type of fresh water, meaning that it contains low concentrations of dissolved substances.

Collecting fresh water

Step 1 in potable water production in the UK is collecting fresh water from a suitable source (one that is not close to heavily polluted areas).

Treating water

Once collected, the water is put through a 2-step treatment process:
1. Filtration: passed through wire mesh to remove solid particles.
2. Sterilisation: chlorine gas is added to kill harmful microorganisms.