UK water companies generated more than £340m in revenue last year by accepting industrial and commercial wastewater at sewage treatment works, according to an investigation by The Guardian. The companies are legally required to process this waste under permits called "trade-effluent consents," though they retain the right to refuse applications.
The investigation found that sewage treatment works across the UK receive billions of litres of industrial and commercial wastewater annually. Experts quoted in the reporting say these facilities are not designed to remove most of the chemical pollutants contained in such waste. Contaminants pass through treatment systems and enter rivers, seas and farmland.
Water companies issue trade-effluent permits to businesses seeking to dispose of their wastewater through the public sewage system. The Guardian's reporting characterises this arrangement as a "black box" trade, suggesting opacity in how the process operates and its environmental consequences.
The scale of revenue involved, £340m annually, indicates the financial incentive water companies have to accept industrial and commercial waste. The reporting raises questions about whether environmental protection adequately constrains the practice, given that treatment works lack the capability to filter many pollutants before discharge.
The Guardian investigation does not specify which water companies generated this revenue, the types of industrial sectors sending waste, or which pollutants most commonly escape treatment. It also does not detail whether regulators have investigated the practice or whether any enforcement action has been taken against specific companies.