Water companies in the UK generated over £340 million in revenue last year by processing billions of litres of industrial and commercial wastewater at sewage treatment works that are not equipped to remove many chemical pollutants. This practice has raised concerns as pollutants are often discharged into rivers, seas, and farmland.

Overview of the Wastewater Trade

Under current regulations, water companies are required to accept industrial wastewater and issue permits known as "trade-effluent consents". These permits allow businesses to send their waste to sewage works, although companies can refuse applications. However, there is no independent regulator overseeing this process, and no central register exists. An investigation by Watershed Investigations, the Guardian, and the campaign group River Action compiled a database of 26,000 consents, providing the first comprehensive view of the system.

The investigation revealed that a total of 608 billion litres of industrial wastewater entered sewage works from various sources, including power stations, pharmaceutical plants, food factories, hospitals, abattoirs, and waste facilities. The permits are issued and enforced by the water companies themselves, with environmental regulators having no direct role.

Chemical Pollutants and Environmental Impact

Most sewage treatment works utilize only biological treatment facilities, which are inadequate for removing industrial chemicals such as:

  • Flame retardants
  • PFAS
  • Solvents
  • Pharmaceuticals

Some permits in the database include hazardous chemicals like cyanide, chromium, cadmium, and mercury. Pollutants that survive treatment are released into natural water bodies as "treated effluent," while those captured in sewage sludge are often spread on farmland as fertilizer. This process contributes to the overloading of sewer networks, leading to raw sewage spills that have sparked community protests and calls for nationalization of the industry.