Wastewater Rainbows

wastewater education lesson

Class-based lesson for pupils in years 5 to 8.

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Your pupils will have the opportunity to discover what wastewater is, how the liquids and solids are treated, and where it ends up. They will also find out how we managed wastewater many years ago.


Your pupils will be set the challenge of making a rainbow. They will carry out a liquid density experiment during which they can change the density of water to make a rainbow. They can also practise their colour-mixing skills.

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You may also like to download the following resources:

Mangere Wastewater Treatment Plant

​The wastewater process

Te Reo Māori water cycle posters

Water cycle game with Te Reo Māori names

Te Reo Māori water cycle answers