Waste Water from Manufacturing

Manufacturing digital devices often uses water to wash equipment, cool machinery, dissolve chemicals or carry materials. Once it has been used, that water may hold substances that were not in it before. Waste water from manufacturing is water that leaves a process after being used, and it can be contaminated.

What contamination means

Contaminated means the water contains harmful substances. These might be acids or alkalis from cleaning, oils from machines, solvents, detergents or tiny metal particles. Water can be contaminated even when it looks clear. For example, a factory making tablet screens washes glass panels with water; the waste water carries fine glass dust and polishing chemicals. If it flows into a stream, the chemicals can harm fish, and the glass dust settles in the mud.

Pollution when it is released uncleaned

If contaminated waste water is released without being cleaned, it can pollute rivers, seas and land. In a river, chemicals can poison fish and the insects they feed on, and suspended particles can block light so water plants struggle to grow. In the sea, pollution can spread along the coast and harm shellfish and other creatures. On land, contaminated water can soak into soil, damage crops and collect in puddles or muddy ground where animals drink.

Harm to people and wildlife

People can be harmed if they swallow contaminated water by accident, or if spray from waste water gets into their eyes or a cut. Wildlife can be harmed directly, for example birds feeding in polluted mud may take in toxic substances, or indirectly as poisons build up through a food chain. Factories can reduce this by cleaning waste water before release: letting solids settle, filtering particles, neutralising acids and alkalis, or treating it with chemicals. Releasing it uncleaned into the environment can cause this pollution.