Water Use in Manufacturing

Water is a renewable resource: rain refills rivers, lakes and reservoirs through the water cycle, so the supply keeps being replaced. Even so, making digital devices can use large amounts of it. A factory that moulds the plastic cases for headphones, for example, uses water to cool the moulding machines and to wash leftover plastic and oil out of the moulds between production runs.

That water is usually drawn from a river, a reservoir or a borehole underground. A factory that takes a lot can leave less for the town around it: families in their homes, a local leisure centre with its pool, a nearby bakery, and farms that irrigate their crops. The river suffers too, because very low water levels can harm the fish, insects and plants that live in it. Water is renewable overall, but the amount available in one place at one time is limited, so heavy use can lead to water scarcity.

Before a factory can use it, water usually has to be collected, treated and delivered. Pumps lift it, filters and chemical treatment take out grit and impurities, and pipes carry it to the factory gates. Every one of those steps needs energy, and most of that energy comes from power stations that burn fossil fuels.

Burning those fuels releases carbon dioxide, a greenhouse gas. Extra carbon dioxide in the atmosphere traps more heat and adds to global warming. Water use in manufacturing is therefore linked both to local water shortages and to climate change.