The Times: Campaigners demand action over Windermere blue-green algae
Campaigners have urged the new environment minister to act after levels of blue-green algae in Windermere exceeded World Health Organisation safe guidelines for swimming in England’s largest lake.
Blue-green algae, also known as cyanobacteria, can be toxic to humans, causing rashes, vomiting and fever. For animals the microbe can be deadly and it devastates fragile aquatic ecosystems by starving them of oxygen.
To form large blooms in Windermere, the microbe requires nutrients including phosphorus and nitrogen, which come from three main sources: sewage treatment works run by the local water company United Utilities, farming and private septic tanks.
The Save Windermere campaign is demanding that United Utilities crack down on its share of the pollution. The company’s treatment works in Ambleside, on the banks of Windermere, released a blend of raw sewage and rainwater for more than 1,700 hours in 2020.
The campaigners are also calling for Steve Reed, the environment secretary, to have the Environment Agency regularly test whether the Windermere blooms are producing toxins.
Samples taken by the Save Windermere campaign last month at Ambleside showed cyanobacteria concentrations that far exceeded the WHO guidance for recreational use of the lake.
The samples were taken after an algal bloom was spotted, extending about 100 metres along the shoreline and stretching between 5-10 metres into the lake. People were swimming in the water at the time.
Three samples taken in the worst affected area were well above the WHO cyanobacteria recreational limit of 100,000 cells per millilitre (mL) — at 666,846 cells/mL, 772,182 cells/mL and 809,298 cells/mL. Analysis showed that toxins were not being produced at the time of testing.
The samples were analysed by Dr Nick Everall, former principal biologist at Severn Trent Water and a registered expert witness. “Sixty to 70 per cent of blue-green algal blooms produce toxins and other bi-products which can cause allergic skin reactions and vomiting sickness when ingested by humans,” he said.
“Certainly monitoring of recreational waters should be adequate to protect all water users and allow them to make their own informed decisions on health and safety.”
Matt Staniek, founder of Save Windermere, said: “In the face of a changing climate, these blooms are going to become an increasing concern. Not enough has been done to protect Windermere and ensure its long-term health. This is as much about the failure of the regulator as it is of the water company.
“Despite United Utilities claims about their investment in the catchment, they are still the largest source of nutrients feeding the blue-green algae in Windermere and they have prioritised dividend return over environmental protection.”
