We all turn on the tap and expect pure, clean water to flow. Then after we've used water, we pull the plug or chain and it is taken away, cleaned and returned to the environment.

But have you ever wondered how this happens? Water is a complicated business but you can learn all about it here.

There are a number of treatment processes for both drinking water and wastewater that are designed to produce high quality water and protect the environment.

• Water treatment
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