Testing by citizen scientists of a estuary flowing into Windermere has revealed a major loss of invertebrate life in the lake. Cumbria which campaigners say is caused by sewage discharge.
Save Windermere and WildFish carried out tests on invertebrates in Cunsey Beck, a Site of Special Scientific Interest (SSSI), to assess the impact on its freshwater ecology of the Near Sawrey Wastewater Treatment Works, owned and operated by United Utilities.
Their first-year results showed a 76% decrease in river fly species and a 33% reduction in river fly diversity in samples taken below the sewer outlet compared to samples taken above it.
They said the permit issued by the Environment Agency – setting out when raw sewage can legally be discharged from the treatment works and providing limits for toxic pollutants – is not fit for purpose.
Save Windermere and WildFish say their findings indicate chronic damage to Cunsey Beck as a result of the regulatory failure of the EA. The stream was hit by a serious pollution event in 2022 that killed hundreds of fish, while Lake Windermere became the focus of national concern over sewage spillage and extensive algae.
Like all rivers in England, Cunsey Beck is affected by pollution from sewage – both raw and treated – and agricultural run-off. No river in England pass pollution tests for chemical and biological pollutants.
Cunsey Beck is categorized as having a “poor” ecological status under the pollution tests in the EU-derived Water Framework Directive. But despite the plight of the stream, which flows directly into Lake Windermere, campaigners say the agency has not carried out any invertebrate sample tests in the river for 10 years.
“The Environment Agency has shown time and time again that they are not fit for purpose. Not only should they review this permit immediately, they should never have allowed it in the first place. They are failing to protect our natural world and this is particularly disturbing within the Windermere catchment,” said Matt Staniek from the Save Windermere campaign.
Save Windermere is calling for urgent reform of the regulator and a public inquiry. In its analysis, the campaign group, together with Windrush Against Sewage Pollution, (Wasp), reviewed the EA permit for the Near Sawrey treatment works. The groups believe the permit is not sufficient to protect the SSSI.
The limit for ammonia nitrogen, a toxic pollutant, for the works is 30mg per litre. The groups compared it to permits for Thames Water where only one site had a similar limit, while 222 other permits had limits of 18mg/l or lower. Staniek said the cap on discharge in an SSSI is inappropriate.
Wasp ecologist Vaughan Lewis said: “The data from our SmartRivers monitoring shows that freshwater invertebrates are negatively affected by water quality in the Windermere catchment, and this is particularly evident downstream of United Utilities assets. Biodiverse invertebrate communities are a cornerstone of healthy freshwater ecosystems. We urgently need action to improve the ecological condition of these waterways.”
Revelations about the permit and the impact of pollution on the invertebrate population in the mouth come to an internal report found there had been a series of failings by the EA in the way it investigated the serious pollution of the mouth in 2022.
The independent report, obtained under freedom of information legislation by WildFish, found the EA had failed to properly investigate the serious pollution in the summer of 2022. The report by the Scottish Environment Protection Agency said the failures meant no source of the pollution had been identified not. The EA said at the time that it recognizes that there are things it should have done better and that improvements are being made.
A United Utilities spokesman said: “The Near Sawrey wastewater treatment plant is operating in accordance with its environmental permit as determined by the Environment Agency.”
An Environment Agency spokesman denied the permit was fit for purpose and pointed out that the UU permit had already considered the SSSI status of Cunsey Beck. They added that recent modeling has shown that the EA limits ensure a good ecological status for ammonia. We carried out invertebrate samples in Cunsey Beck as recently as June 2023”.
“We are committed to further improving the water quality in Lake Windermere and are working closely with various organizations as part of the Love Windermere partnership to do this. As part of this work, we have begun the process of reviewing all the permits for this lake to determine if there are any further steps we can take.”