How UK Water Firms Make £340m From Industrial Wastewater
UK water companies earned more than £340m last year from accepting industrial and commercial wastewater at sewage treatment works, according to analysis published on 9 October 2026. The Guardian
The estimate is based on a database of 26,000 trade-effluent consents compiled by Watershed Investigations with the Guardian and River Action. It puts the permitted annual flow at 608bn litres of industrial wastewater entering sewage works from power stations, pharmaceutical plants, food factories, hospitals, abattoirs and waste facilities.
United Utilities earned £61.6m from industrial waste last year, the most of any UK water company. Yorkshire Water earned £48.8m. By permitted volume, Thames Water is largest at 113bn litres, followed by United Utilities at 105bn litres and Severn Trent Water at 79bn litres. At Anglian Water, revenue from receiving industrial and commercial wastewater rose 62% over five years.
Trade-effluent consents are permits that allow businesses to send industrial wastewater to sewage works. Think of them as permission slips that set what a factory or hospital can put into the public sewers. 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 detail points to a structural tension, because the same company collects the fee and polices the permit. The commercial transaction and the compliance function sit inside the same business.
The broader context here is sustained pressure over sewage performance. In March 2022, the UK water regulator tightened scrutiny of five water firms and asked firms to submit information about how many 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 could mean 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. Volumes above 100bn litres at individual companies point to 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.
