Pollution in Windermere: Will water companies clean it up?

Windermere residents are once again being warned not to swim in England’s largest lake, after water quality tests at Waterhead found elevated levels of harmful bacteria associated with faecal matter. 

Bacteria is not the only risk. As summer temperatures continue to rise, it is believed that the risk of algal blooms on Windermere is growing. Algal blooms strip water bodies of oxygen and prevent sunlight from penetrating its surface, harming its entire ecology. Algae can also be harmful to health, as seen in May when people were warned not to swim at Lakeside YMCA in Windermere due to reports of blue-green algae. They are caused by excessive nutrients in the water and their growth becomes more rapid in warmer weather. 

Nutrient pollution has been a serious issue in Windermere and the most recent figures suggest that without change the health of the lake will continue to decline. The BBC reported that in 2024, United Utilities discharged untreated sewage into Windermere on 140 days, more than in any of the previous three years where data has been available. Sewage is high in phosphorus, one of the primary contributors to the growth of algal blooms. The Environment Agency previously attributed 30-46% of all phosphorus pollution in Windermere to United Utilities’ operations, making it the largest single entity polluting the lake. 

The need for change has been clearly recognised in Windermere and progress is being made. In March, Environment Secretary Steve Reed pledged to “clean up Windermere” and announced a feasibility study investigating the requirements to fully remove sewage discharges from Windermere. The study is to be carried out by a coalition of local stakeholders and organisations including United Utilities, the Environment Agency, Ofwat, Save Windermere, Love Windermere, the Lake District National Park authority, and Westmorland and Furness Council. 

This is a positive step, removing all sewage discharges from Windermere would help to protect against further damage and lay the necessary foundations for the lake’s restoration to its natural beauty. However, in light of recent events, there remains reason to be cautious.  

Our primary concern with this study is the leading role which United Utilities is positioned to play. As outlined above, United Utilities has been identified as the largest polluter of Windermere, and it discharged untreated sewage into Windermere more in 2024 than in any of the previously recorded years. Nonetheless, the company reported that over the same period it had doubled its profits from the previous year, even before raising its bills by 32%.  

Can water companies be trusted to take the lead in preventing pollution which has resulted from their own activities without increasing the cost to customers?  

It is also important to remember that a feasibility study is not a full commitment to remove sewage discharges from Windermere. United Utilities completed its own feasibility study for such a project in 2023, with no further action taken.  

As lawyers investigating the potential for a legal claim over sewage pollution in Windermere, we say it is essential that a new study leads to positive action.  

We believe that a legal action brought by members of the community will help to sustain pressure on United Utilities to deliver on its promises to clean up the pollution of Windermere. 

Group litigation would give those individuals and businesses who have been affected by pollution in Windermere a voice and use the power of the law to pressure United Utilities to take action. Under the ‘polluter pays’ principle, United Utilities could be ordered to account for the harm it has reportedly caused to England’s most iconic lake. Legal action could also lead to an injunction by the court, ordering United Utilities to follow through with such a scheme. 

In light of these considerations, Leigh Day continues to believe that legal action may play an important role in advocating for the health of Windermere and the rights of the local community. Our specialist environmental legal team is examining any impact that sewage pollution in Windermere may be having on the local community. 
  
To register your interest in a potential legal claim and to receive updates from us, please complete the online form here.