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Gallery 8

# Hidden Water

Water used to manufacture items such as food,  clothing and cars is called embedded water.

## How it works

This multimedia exhibit calculates the amount of embedded water in an everyday object (e.g. the volume of water used to manufacture a pair of jeans). Also discover which part of the object’s manufacturing process uses the most water.

## Things to try or ask around the exhibit

• Let's see if we can calculate how much water was used to produce the clothes I'm wearing now.
• Would something 'dry' like a sheet of paper require less water to produce than something 'wet' like a piece of fruit?

## Background

You may assume that it only takes one litre of water to produce one litre of milk, but typically, 1000 litres of water is actually required to manufacture that one litre of milk. By measuring and estimating volumes of water required to manufacture something from start to finish, a product's 'embedded water' can reveal the environmental impact of manufacturing and consuming that product. So to manufacture the milk, farming companies need to grow crops to feed the cow, wash and sterilise factory equipment, produce the milk and undertake other manufacturing processes, the volume of water required to produce something such as milk.

## Finding the science in your world

Even seemingly 'dry' products require surprising amounts of water for their production. One sheet of A4 paper typically requires around 10 litres of water to produce, which is about one bucket of water per sheet of paper. Hence, an A4 folder full of note paper would take many thousands of litres of water to produce.