In 2024, England’s largest lake, Windermere, experienced an unprecedented level of illegal sewage discharge, according to a new analysis conducted by environmental campaigners.

Using operational data from United Utilities—the water company responsible for the region—activists from Windrush Against Sewage Pollution (WASP) and Save Windermere uncovered 140 days where raw sewage was spilled into the lake in apparent violation of environmental laws.

This figure exceeds that of any of the previous three years, marking a disturbing record in a growing environmental crisis.

The campaigners’ analysis focused on periods where United Utilities was discharging sewage when it should have been processing it, as mandated by environmental permits. These permits typically allow companies to release sewage only when treatment facilities are overwhelmed, such as during heavy rainfall.

However, the law also stipulates that a minimum volume of wastewater must be treated before any overflow is discharged. By comparing spill events with treatment volumes, the campaigners were able to identify repeated violations across six sewage facilities around Windermere.

United Utilities, however, rejected the analysis, calling it “inaccurate” and based on “erroneous” data. Despite repeated requests, the company declined to provide any written evidence or specific examples to back up its claims.

Regulators—namely the Environment Agency (EA) and Ofwat—are currently investigating United Utilities as part of broader inquiries into the practices of several UK water companies. The EA has described its probe as a “major criminal investigation,” while Ofwat has labeled it the most extensive and complex investigation it has ever undertaken.

Windermere, located within the Lake District National Park and a UNESCO World Heritage Site, is home to over 14,000 residents and attracts approximately seven million visitors annually. But its reputation as a pristine natural retreat is under threat. Excessive sewage discharges have increased nutrient levels in the lake, contributing to algal blooms that cloud the water and disrupt aquatic ecosystems.

The problem is not new. In 2023, an investigation revealed that a single pumping station near Windermere had illegally released over 140 million litres of raw sewage over a three-year period. The same year, a report accused United Utilities of misreporting pollution events.

This March, Environment Secretary Steve Reed condemned the situation, calling the pollution “a disgrace” and pledging government intervention to clean up the lake.

The data examined by campaigners spans four years and is limited to the period since United Utilities began publishing complete datasets in 2021. Their findings reveal that the worst continuous illegal spill lasted ten days, originating from the Hawkshead pumping station, which drains into the lake via Cunsey Beck.

“This is an indication that their works have not been maintained properly or they’re not being watched over properly,” says Prof Peter Hammond, a mathematican and retired academic from campaign group Windrush Against Sewage Pollution.

Professor Peter Hammond, a data analyst whose work has previously been cited by regulators and even praised in Parliament by water company executives, supported the analysis. His review further validates the campaigners’ findings and underlines a systemic problem in the way sewage is managed and reported.

The Environment Agency, in response to growing concerns, reviewed all environmental permits within the Windermere catchment last year. This review prompted United Utilities to triple its planned investment in the region, raising its commitment from earlier estimates to £200 million. These funds are intended to improve nine wastewater treatment works, including two that were implicated in the latest analysis, and reduce the number of storm overflows discharging into the lake.

“We are currently carrying out investigations into suspected pollution incidents on the Windermere catchment and are unable to comment on these in detail until they have reached a conclusion,” an EA spokesperson said when the campaigners’ analysis was shared with them.

“Where we find breaches of environmental permits, we will take the appropriate enforcement action up to and including a criminal prosecution.”

Despite this planned investment, United Utilities’ public image has been further tarnished by its financial disclosures. The company, which serves over seven million people in northwest England and carries a debt load exceeding £9 billion, faced public scrutiny after revealing that its CEO, Louise Beardmore, received £1.4 million in pay last year—including a £420,000 bonus.

“The methodology used by the campaigners is different to that used by the Environment Agency for its compliance assessments,” the water company said in a statement.

“On top of that, erroneous data has been used, tags and naming conventions in data sets appear to have been misunderstood, and assumptions seem to have been made on whether different types of flow meters have been installed.”

“The methodology fails to use other corroborating information from the sites which would prove that spills did not occur. As a result, the numbers quoted are inaccurate.”

When confronted by the BBC with five specific examples of alleged illegal spills, drawn directly from the company’s own data, United Utilities declined to provide an explanation or rebuttal either on camera or in writing.

Meanwhile, customers will feel the financial impact of these environmental and regulatory challenges.

“What we’re seeing is the failure of privatisation. We’re seeing a prioritisation of dividend returns over the long-term environmental protection of places like Windermere” says Matt Staniek from Save Windermere.

“The bill payer has paid for a service that has never fully been provided, and the illegality demonstrates that for all to see.”

Over the next five years, water bills in the United Utilities service area are set to rise by 32% above the rate of inflation. For the average household, this translates to an increase of £86 starting in April.

As public pressure mounts and legal scrutiny intensifies, Windermere has become a focal point in the UK’s broader battle over water quality, corporate accountability, and environmental protection. While United Utilities has pledged improvements, many remain skeptical, calling for greater transparency and urgency in restoring the health of one of the nation’s most cherished natural landmarks.

 

 

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