Key facts
- UK water companies earned over £340 million last year from industrial wastewater.
- 608 billion liters of industrial wastewater entered UK sewage works.
- Most sewage works are not designed to remove industrial chemicals.
- Pollutants can enter rivers, seas, and farmland or trigger raw sewage spills.
- There is no independent regulator or central register for the trade-effluent consent process.
- Water companies issue and enforce their own permits for industrial wastewater.
UK water companies generated over £340 million in revenue last year by accepting billions of liters of industrial and commercial wastewater into sewage treatment works that are not designed to remove most chemicals, according to an investigation by Watershed Investigations, The Guardian, and the campaign group River Action.
The investigation compiled a database of 26,000 trade-effluent consents, revealing that 608 billion liters of industrial wastewater entered sewage works from various sites, including power stations, pharmaceutical plants, and hospitals. The permits, which allow businesses to send wastewater to sewage facilities, are issued and enforced by the water companies themselves, with environmental regulators having no direct oversight.
Industry experts described the process as a "black box" and noted that most sewage works primarily use biological treatment, which is ineffective against industrial chemicals like flame retardants, PFAS, solvents, and heavy metals such as cyanide, chromium, cadmium, and mercury. Pollutants that are not removed are discharged into waterways or spread on farmland as sludge, while the waste also contributes to the overloading of sewer networks, leading to raw sewage spills.
United Utilities reported the highest revenue from industrial waste at £61.6 million, followed by Yorkshire Water at £48.8 million. Thames Water handles the largest volume of permitted industrial sewage, with 113 billion liters, followed by United Utilities (105 billion liters) and Severn Trent Water (79 billion liters). Revenues from this trade have increased significantly over the past five years, with Anglian Water's revenue rising by 62%.
An industry expert suggested that water companies have a "financial incentive to accept far more toxic material than they should," and that the current permit regime is outdated. An Environment Agency officer highlighted landfill leachate as a major concern due to its chemical composition and noted that basic tests by water companies are insufficient to identify most contaminants. The officer stressed that "ignorance is no defence" and companies should seek adequate information from waste producers.
Amy Fairman, head of campaigns at River Action, stated that "industrial pollution must not become a lucrative business for water companies" and called for polluters to be held accountable. A spokesperson for the Department for Environment, Food and Rural Affairs acknowledged that the water industry has not been working in the public interest and that reforms are underway. The Environment Agency is working to improve the management of contaminants, recognizing that the trade-effluent framework is over 30 years old and predates current concerns about substances like PFAS.