Every water and wastewater company in England and Wales under investigation for sewage spills

OFWAT is now investigating all 11 water and wastewater companies in England and Wales for wastewater treatment practices after launching four more enforcement cases.

The water regulator has issued formal notices on Dŵr Cymru Welsh Water, Hafren Dyfrdwy, Severn Trent, and United Utilities, adding to the ongoing cases against Anglian Water, Northumbrian Water, Southwest Water, Thames Water, Wessex Water, Southern Water and Yorkshire Water.

Ofwat has been running its investigations in parallel with the Environment Agency’s (EA) criminal investigations since 2021 after water companies admitted that they may be releasing unpermitted sewage discharges into rivers and watercourses. Both bodies are investigating more than 2,000 wastewater treatment works.  

David Black, Ofwat chief executive, said: “This is the largest and most complex investigation Ofwat has undertaken.”

He added: “The fact that Ofwat now has enforcement cases with all 11 of the wastewater companies in England and Wales demonstrates how concerned we are about the sector’s environmental performance.”

Unnecessary sewage discharges

The EA issues water companies with environmental permits with conditions attached on how to treat wastewater before it can be released into the environment.

Companies have flow to full treatment (FFT) operations that measure the amount of wastewater they can treat at any given time. Ofwat’s investigation involves these operations.

If wastewater levels exceed FFT due to storm overflows, environmental permits allow companies to dispose of partially treated water into the environment.

However, with more wastewater monitoring equipment being installed at treatment works, water companies have admitted that they may have discharged untreated wastewater.

The 2022 EA water and sewerage performance report for companies in England found that there had been 2,026 pollution incidents, up from 1,883 the year before.

For its investigation, Ofwat requires all water companies to provide information on how many discharges they have made and why, and how they intend to reduce unprohibited spills.

Financial penalty

Ofwat says any company found to have breached its environmental permit will be subject to prosecution, enforcement actions, and fines.

The fines can be up to 10% of the company’s annual turnover for civil cases, or unlimited in criminal proceedings.

In 2022, Ofwat ruled that Thames Water and Southern Water would have to return around £50m (US$65m) and £30m respectively to customers due to missed targets on treatment works compliance.

The regulator has imposed penalties and payments of more than £300m on companies who have failed to comply with treatment conditions.

However, Ofwat maintains that it supports the efforts of companies that are trying to reduce discharges, including Severn Trent which plans to invest £4.4bn across 25 years to improve wastewater storage capacity and treatment.