Millions of gallons of sewage has been illegally pumped into England’s largest lake in recent years, a BBC investigation has claimed.
According to the report, from the beginning of 2021 to the end of 2023, waste management company United Utilities illegally pumped at least 36 million gallons / 136 million liters of potentially hazardous, untreated sewage into historic Lake Windermere, a popular spot for wild swimming.
In the UK, water treatment companies release untreated sewage into open water when heavy rainfall threatens to overwhelm water waste management systems. In this case, United Utilities is authorized to release raw sewage into the lake during wet weather if at least 54 gallons / 245 liters per second are still going to treatment works.
But the BBC says data it has seen reveals that United Utilities repeatedly failed to comply with these regulations, releasing sewage into the lake for a combined 165 hours while an insufficient amount was sent for treatment. In that time, between 37.8 million gallons / 143 million liters and 75.6 million gallons / 286 million liters of untreated sewage were released into Windermere, which campaigners say could have a potentially devastating effect on its environment.
In July 2022, amid the height of the wild swimming season, Windermere turned bright green due to algal blooms. Caused by a combination of warm temperatures and nutrients, algal blooms discolor and increase toxicity in open waters. They're worsened by the release of sewage as it’s often rich in nutrients.
Only a month before, Windermere had hosted the Arla Great North Swim, the UK's largest wild swimming event, with 7,500 swimmers swimming around the Brockhole section of the lake.
United Utilities told Advnture it was aware of the releases, saying in a statement: “In January 2024, we discovered an engineering issue on the configuration of the Windermere system that meant some of the discharges recorded by our Event Duration Monitors were potentially non-compliant. Even though these spills were happening when it was wet and our storage system was already full and spilling, we reported them to the Environment Agency as soon as we became aware of the situation.”
But the BBC claims United Utilities still failed to flag at least 26.9 million gallons / 102 million liters of untreated sewage.
Described as a ‘chemical cocktail’ by lawmakers, British and Northern Irish waters have become increasingly polluted in recent years, with around 35% stemming directly from excess sewage dumps. In 2021 alone, the river Thames, which runs through London and much of southern England, was bombarded by 8.4 billion gallons / 32 billion liters of excess sewage.
The weight of this increased pollution has fallen heavily on the UK’s open water swimmers. Last June, at least 35 competitors experienced sickness after taking to the Thames for the Royal Windsor Triathlon, while swim campaigners have warned Olympic open water hopefuls may miss out on future medals due to a lack of safe training spots.
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