UK Water Firms Made £340m From Industrial Wastewater Under Self-Issued Permits
UK water companies generated more than £340m in revenue last year from receiving industrial and commercial wastewater into sewage treatment works, according to analysis published on 9 October 2026. The Guardian
The figure is based on a database of 26,000 trade-effluent consents compiled by Watershed Investigations with the Guardian and River Action. The database puts the annual permitted flow at 608bn litres of industrial wastewater entering sewage works from sites including power stations, pharmaceutical plants, food factories, hospitals, abattoirs and waste facilities.
United Utilities made £61.6m in revenue from industrial waste last year, the most of any UK water company. Yorkshire Water made £48.8m. By permitted volume, Thames Water holds the largest position at 113bn litres, followed by United Utilities at 105bn litres and Severn Trent Water at 79bn litres. Anglian Water's revenue from receiving industrial and commercial wastewater increased by 62% over five years.
Trade-effluent consents are the permits that allow businesses to send industrial wastewater to sewage works. They are issued and enforced by the water companies themselves with no direct role for environmental regulators. Some permits cover chemicals including cyanide, chromium, cadmium and mercury.
The mechanism is a standard part of sewerage charging. In Scotland, a business must obtain a trade effluent consent or enter a trade effluent agreement with its water and sewerage company before discharging trade effluent. Ofwat's RAG 4 Appendix 1 on income categorisation includes a fee for trade effluent consent revision. Ofwat Respondents to Ofwat's 2025-26 review of Retail Exit Code protections argued that surface water drainage and trade effluent charges are poorly captured by consumption-based caps. Ofwat
That is self-regulation with revenue attached. The commercial transaction and the compliance function sit inside the same company.
The broader context here is sustained regulatory and legal pressure on sewage performance. In March 2022, the UK water regulator tightened scrutiny of five water firms and asked water firms to submit information about how many of their sewage treatment works might not be meeting requirements. Reuters In May 2023, Britons protested against water companies over dumping of raw sewage and poor river quality. Reuters
Six British water companies later faced lawsuits alleging they under-reported sewage discharges and overcharged customers by up to 1.5 billion pounds ($2 billion). Reuters In October 2024, Ofwat said the water industry was falling far behind a target to cut sewage spills by 30% over 2020-25, and UK water firms were required to cut customer bills by $206 million. Reuters
Looking at what this means for policy, the trade-effluent data adds an industrial layer to a debate that has centred on household sewage and storm overflows. The questions for regulators and investors concern capacity, influent risk and oversight. Sewage works receive domestic sewage plus very large permitted industrial flows. Permits can authorise hazardous substances. Enforcement rests with the revenue recipient.
For an expert audience, the figures to weigh are scale and trajectory. More than £340m is material non-household income. Volumes above 100bn litres per company indicate concentrated industrial loading in specific catchments. A 62% five-year revenue increase at one company points to growth in the trade-effluent book, whether from volume, tariff or customer mix. None of those points resolves whether treatment performance is affected. They define where to look next: consent conditions, monitoring data, and how industrial load interacts with spill frequency and compliance at receiving works.
